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Hohm Tech Work V2 18650 2547mAh 25.3A Battery

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Description

Specifications.

You MUST read the safety warnings and resources before purchasing, using, and/or handling batteries.

warning WARNING:

Before handling and/or using a Hohm Tech lithium-ion battery, please read: Hohm Tech’s Battery Safety Information

Use caution as misusing or mishandling the battery may cause a FIRE or EXPLOSION which may result in personal injury, property damage, or death. The user must have an appropriate understanding of the potential dangers of LITHIUM ION BATTERIES before purchase and usage. No express or implied guarantee of compatibility, suitability, or fitness for any particular purpose or device can be made. This battery is manufactured and sold for the intended use of system integrations with proper protection circuitry or battery packs with a BMS (battery management system) or PCB (circuit board/module). This battery is neither designed nor intended to be used with an E-CIGARETTE, VAPORIZER, or similar device and MUST NOT be used with such devices due to RISK OF FIRE or EXPLOSION. If purchasing this battery for resale purposes, you MUST forward ALL warnings to ALL customers for their reference and safety! 

• DO NOT USE WITH E-CIGARETTE, VAPORIZER, OR SIMILAR DEVICE
• Additional battery manufacturer and battery industry association warnings for using lithium-ion batteries in e-cigarette or vaping devices can be viewed here: Be-CigaretteSafe.org
• BATTERY IS ONLY FOR USE IN PROTECTED BATTERY PACKS
• ONLY ASSEMBLE A BATTERY PACK IF YOU ARE COMPETENT IN DOING SO
• DO NOT STORE BATTERY/CELL LOOSE OR IN A POCKET, PURSE, ETC. ALWAYS USE A PROTECTIVE CASE OR BOX FOR STORAGE AND TRANSPORT
• WHEN NOT IN USE, ALWAYS STORE LITHIUM ION BATTERIES IN THE PROTECTIVE CASE/BOX IN WHICH BATTERIES WERE DELIVERED
• Misusing or mishandling lithium ion batteries can pose a SERIOUS RISK of PERSONAL INJURY, PROPERTY DAMAGE, OR DEATH
• BATTERIES MAY EXPLODE, BURN, OR CAUSE A FIRE IF MISUSED OR MISHANDLED
• Usage of batteries is AT YOUR OWN RISK!
• ONLY use with proper protection circuitry
• DO NOT short circuit intentionally or unintentionally
• KEEP AWAY from metal/conductive objects to prevent short circuiting
• DO NOT use if PVC wrapper or terminal insulator is damaged or torn
• DO NOT use if battery is damaged in any way
• DO NOT over-charge or charge above the maximum voltage rating
• DO NOT over-discharge or exceed the continuous discharge rating
• DO NOT modify, disassemble, puncture, cut, crush, or incinerate
• DO NOT expose to liquids or high temperatures
• DO NOT solder onto battery, spot weld only
• DO NOT use force to install or install in reverse/backwards
• ONLY use within manufacturer’s specification
• KEEP AWAY from pets and children
• ALWAYS charge in or on a fire-proof surface and never leave batteries charging unattended
• ONLY use a smart charger designed for this specific type of battery
• DO NOT mix and match brands and models, old and new, used and unused batteries
• STOP immediately if while charging/storing/using the battery it emits an unusual smell, feels hot, changes color or shape, or appears abnormal in any way
• It is your responsibility to determine that your charger or device is functioning properly
• If exposed to battery electrolyte, flush with water immediately and/or immediately contact a physician or emergency services
• DO NOT throw away in trash; contact your local jurisdiction for proper recycling or disposal
• Resellers MUST forward ALL warnings to ALL customers for their reference and safety

BATTERY TYPE, NOMINAL VOLTAGE, DISCHARGE CURRENT (AMPS), NOMINAL CAPACITY (MAH),

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SPECIFICATIONS:

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Heartbeat of Hohm Tech

PERFORMANCE | CAPACITY | SAFETY

Advanced Battery Chemistry

…built to push harder, longer, with utmost safety

Brochure >

Learn More >

Battery Safety Information (BSI) >

We emphasize safety while aiming for chart-topping performance.

TIRED OF COUNTERFEITS? So are we. Every Hohm Tech cell comes standard with a proprietary embossed power guard to ensure authenticity.

18650 : HOHM LIFE 4 | WORK 2 | ALONE 18650 ( NEW ): HOHM DEPOT | MEGA 20700 : SHERLOCK 2 HOHM 21700 : HOHM RUN | RUN XL 26650 : HOHM GROWN 2

Specifications

Started with raw materials sourced from multiple renowned providers

Lowered internal resistance by a multitude of various internal modifications (used UHPAI for cathode tag, shortened cathode tag, among other mods)

After 1000’s of trials and tests, we zero’d in on the perfect combination of what we call PPLS (Price, Power, Longevity, & Safety)

Expanded our safety efforts by placing a stronger bitumen compound Poly Seal in every battery

HOHM WORK 2 > Learn More Learn More

Power Demanding Devices?  Bring’em On!

2547mAh | 25.3A CDR | 35.8A @ 80 o C cut-off

Can be charged at a tested/proven 3.82A rating: Yes, 3.82, as in THREE POINT EIGHT TWO. It is possible, tested, proven, and approved**

Phenomenal amperage delivery to drive power demanding devices

Purest form of Li-NMC (Nickel [Ni], Manganese [Mn], Cobalt [Co]) used to date

Exceeds all previous designs and chemistry results with greater amperage and capacity

EPTC (Enhanced Positive Thermal Coefficient): Reduction in Thermal Runaway potential

Updated Poly Seal: Enhances security of seal & proper operation

Cathode Tag made from UH Purity Aluminum: Ultra-High Purity (UHP)

Ahead of schedule chem bonding to U-Mn specifications: one of many processes conducted to achieve documented specs

NEW chemical stimulation and unity process achieves greater purity: Cycle Life is increased to 69% nominal average of original capacity

NEW meld process over 7kHz: results in charge rate capable of 3.82A

Ahead of schedule chem bonding to  Li-Mn specifications

Phenomenal amperage-to-capacity ratio to drive power demanding devices

NEW HT 5-brace embossed top to alleviate impostures from distributing fakes in the industry

Many proprietary processes conducted to achieve documented specs

HOHM ALONE > Learn More Learn More

The Do-It-All-Day Battery

3309mAh | 15.3A CDR | 19.6A @ 80 o C cut-off

Can be charged at a tested/proven 4.14A rating: Yes, 4.14, as in FOUR POINT ONE FOUR. It is possible, tested, proven, and approved**

NEW NiMnCo Meld over 7kHz: process increases charging rate to 4.14A (1.25C) compared to standard 0.5C – 1C rates of Li-NMC formulation

Utilizing industry-unique QSP Li-NMC (4x raw compound wash)

Exceeds all previous designs and chemistry results with greater amperage-to-capacity ratio in 18650 format

Purpose-built to take on both high amperage and high capacity tasks simultaneously. Utilizing proprietary structure, top cap, and QSP chemistry in the Li-NMC family. More amps ~ cooler temps ~ even safer.

HOHM DEPOT > Learn More Learn More

Your New Superpower!

3005mAh | 16.8A CDR | 22.5A @ 80 o C cut-off

Can be charged at a tested/proven 3.60A rating with minimal impact to degradation

Amperage delivery at sustained voltages ensures powering relevant loads

Recalibrated chemistry formula comprised of DSP compounds

Progressive amperage-to-capacity and capacity-to-weight

Equipped with the UPS sealing compounds as an extended assurance of proper operation and performance

DSP (Dual Stripping Process) formula and selection of raw chemistry achieves a greater cycle life than any previous Hohm Tech cell

2nd Gen Cathode Tag integration to promote reduction in internal resistance

NEW slurry stir process enables greater consistency and minimizes cell-to-cell variation

Proprietary ACT (Anti-Counterfeit Top) embossment on every Hohm Tech cell

UPDATED test procedures validate greater cycle life for the Hohm Tech DSP cells

HOHM MEGA > Learn More Learn More

The Superhero Battery

2505mAh | 22A CDR | 29.5A 80 o C cut-off

Can be charged at a tested/proven 4.14A rating: Yes, 4.14, as in FOUR POINT ONE FOUR. It is possible, tested, proven, and approved

Designed to drive both inefficient and power-demanding devices to help get to where you need to

Utilizing the DS (2x Stripping) process; resulting in an effective method of consistent performance

As all cells, it too is enabled with the OLC for swift understanding of capabilities

Built with the refined bitumen Poly Seal to secure the consistency of repeated operation

HOHM LIFE 4 > Learn More Learn More

The ‘GO’ All Day Battery

3015mAh | 22.1A CDR | 31.5A @ 80 o C cut-off

Wattage output up 5% to 63W; Amperage up 6.8% to 22.1A CDR; Capacity up 7.4% @ >15A loads

Designed to feed power-hungry devices without having to swap batteries every other minute

Chemistry enhanced by QSP (quad stripping process), which is proven to deliver greater voltage-sag resistance

A multitude of processes conducted to achieve documented specs

Anti-Counterfeit ‘Ohm’ embossed top to stop knock-offs/clones

NEW Mn bonding process that achieves greater purity: Cycle Life is increased to over 70% nominal average of original capacity

NEW QSP NiCo Meld over 10kHz: process increases charging rate to 4.43A from previous 4.25A

Production date coding now on every cell (applicable to Grown 2 )

UPDATED bonding process that achieves greater end-product purity: Cycle Life @ 80% nominal average of original capacity

HOHM GROWN 2 > Learn More Learn More

Amps & Capacity… Let’s Party

4244mAh | 30.3A CDR | 41.1A 80 o C cut-off

Can be charged at a tested/proven 5.30A rating: Yes, 5.30, as in FIVE POINT THREE. It is possible, tested, proven, and approved

Designed to feed insanely power-hungry devices without having to swap batteries every other minute

Now utilizing our latest Li-NMC chemistry with QS (4x Stripping) process; resulting in our purest chemistry to date

Exceeds all previous designs and chemistry results with greater CDR running at 8 o C cooler than previous model

SHERLOCK 2 HOHM > Learn More Learn More

The ‘DRIVE’ Through Any Task Battery

3116mAh | 30.7A CDR | 41.6A 80 o C cut-off

Can be charged at a tested/proven 4.67A rating: Yes, 4.67, as in FOUR POINT SIX SEVEN. It is possible, tested, proven, and approved**

Originally developed and intended to power automobiles, it has been reformulated and equipped with a proprietary EPTC ring

Not reinvented, rather RE-formulated, achieving a unique blend new to Hohm Tech International

Since date of release, cell progression is up in all amperage and safety tests

EPTC (Enhanced Positive Thermal Coefficient) equipped: Reduction in Thermal Runaway potential

Updated Poly Seal from inception: Enhances security of seal & ensures it excels in various applications and environments

As with all ICHT cells, the Cathode Tag is utilizing UH Purity Aluminum: Ultra-High Purity (UHP) for internal resistance suppression

Ahead of schedule chem bonding to Li-Mn specifications

NEW bonding process that achieves greater purity: Cycle Life is increased to 69% nominal average of original capacity

CoO 2 coalesce process unlocks 1.5C charging rates

World’s First NAI 20700 (non automotive intent) extended with a backing of LLI, GLI, and PLI for robust protection from start to finish

Proprietary “Ohm” cap to ensure utmost authenticity!

QSP process that achieves greater end-product purity: Cycle Life 73% @ 500 cycles of nominal average capacity

Hohm RUN 21700 > Learn More Learn More

Amperage for Serious Power Needs!

QSP Li-NMC | 39.1A-49.5A | 3023mAh | 3.6V

Can be charged at a tested/proven 5.29A rating: Yes, 5.29, as in FIVE POINT TWO NINE. It is possible, tested, proven, and approved

Purpose-built to exceed amperage capabilities of ALL previous non-QSP batteries

Utilizing our latest QSP Li-NMC processed chemistry; resulting in the purest chemistry to date

39.1A CDR runs from 4.2V down to 2.5V @ under 76 o C MAX (Neware Analyzer  |  Palmer Probes  |  22-25 o C Ambient  |  No Moving Air)

Utilizing the proven compound in updated Poly Seal: Enhancing security of seal & proper operation

Hohm RUN XL 21700 >  Learn More Learn More

Hohm RUN XL 21700 > Learn More Learn More

Named Hohm RUN XL for a reason…

QSP Li-NMC | 30.3A-38.6A | 4007mAh | 3.6V

Can be charged at a tested/proven 6.01A rating: Yes, 6.01, as in SIX POINT ZERO ONE. It is possible, tested, proven, and approved**

Development started in 2017 with intent to only power Electric Vehicles.  It’s just too good to keep it restricted to only EV projects

Using the proprietary “Ohm” cap in a 21.5mm width; 71.4mm length structure.  100% blend new to Hohm Tech International

>4k capacity, >30A load, in a structure under 72g weight!

Utilizing same identical seal compounds as Hohm RUN to ensure battery remains sealed in hot/cold weather and applications

QSP Li-NMC with ample cobalt is proving to be desirable to other factories that Hohm Tech International is now licensing the technology to

NEW bonding process that achieves greater purity: Cycle Life is increased to >70% nominal average of original capacity

QSP unlocks consistent and reliable 1.5C charging rates

World’s First NAI 21700 (non automotive intent) cell in compliance of ATD & ANSI, while achieving IEC certification

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Hohm Tech Hohm Work 18650 INR 2531mAh 35.8A Flat Top Battery

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• Description
• Helpful Tips

SAFETY NOTICE / WARNING:    CLICK HERE  

In the world of vaporizer products, the power source is often overlooked. That’s not to disparage its importance, for obvious reasons. However, most enthusiasts – if they’re being perfectly honest – focus understandably on the core, physical features, such as sub-ohm tanks or advanced mods . However, renowned manufacturer Hohm Tech is bringing sexy back to the battery!

The Hohm Tech Hohm Work 18650 2531 mAh 35.8A Battery is one of the latest releases from the company’s innovative power-source brands. Featuring a massive 2,531 mAh capacity, with a 21.5A CDR rating, the Hohm Work is a genuine tour-de-force. Designed for the vaping connoisseur, this bad boy will not leave you stranded.

In addition, the Hohm Work 18650 2531 mAh 35.8A Battery integrates unique, proprietary chemical mixtures to improve performance to levels not previously seen before. This includes a 37% Cobalt (Co) and Nickel (Ni) composition that facilitates superior conductivity and astounding consistency.

Like other Hohm Tech power sources, the Hohm Work utilizes the company’s distinctive EPTC system, or Enhanced Positive Thermal Coefficient. This platform maximizes performance metrics while keeping maintaining safe operating thresholds. The end result is that you can confidently push your vaporizer to its limits without fear of damaging your battery.

Finally, the Hohm Work utilizes a meld process with over 10kHz cycles. This helps increase the charge rate from a previous 4.25A rating to a mind-blowing 4.75A! And like every component within the Hohm Tech product portfolio, the Hohm Work is priced competitively.

WARNING :   LI-ION  CELLS  HAVE INHERENT RISKS IF MISUSED OR MISHANDLED.   CELL CAN EXPLODE   CAUSING SEVERE BURN INJURY, FATALITY, AND PROPERTY DAMAGE.  

– read below thoroughly –.

• KEEP OUT OF REACH  of anyone under 18 years of age, AND pets.
• DO NOT PUT IN FIRE , oven, microwave, or expose to anything over 100 o C ( 212 o F )
• DO NOT  CARRY  or store  OUTSIDE  of its protective packaging or a  PROTECTIVE CELL CASE .
• DO NOT PUT IN POCKET , bag, purse, or anywhere  WITH METAL OBJECTS  including  COINS  and  KEYS . Otherwise, cell(s) could short-circuit and explode.
• DO NOT PUT A DEVICE WITH CELL(S) INSTALLED IN POCKET  or  ON YOUR BODY.   As unlikely as it may be, a device can malfunction, have a defect, internal damage, and/or be affected by conductive debris or object(s) in pocket that can overload or short-circuit cell causing it to explode.
• DO NOT USE IN A DEVICE THAT CAN EXCEED MAX CELL WATTAGE (W)  or  AMPERAGE (A)  ( listed on each cell and retail packaging ).  Otherwise, this can overload a cell, causing it to explode.
• DO NOT USE A LOWER RESISTANCE  (Ω)  # ( listed on each cell and retail packaging ).  Otherwise, this can overload cell, causing it to explode.
• DO NOT USE CELL WITH ANY DAMAGE TO ITS STRUCTURE OR OUTER PROTECTIVE LABEL  ( also called “WRAP”, “sleeve”, “skin” ). Damage may include: dent(s), tear(s), nick(s), puncture(s), corrosion, or any other undisclosed abnormalities or damages.  Otherwise, a cell can short-circuit and explode.   ALWAYS  INSPECT cell VISUALLY and by TOUCH to SEE/FEEL for damage BEFORE EACH USE.   **  SEE ILLUSTRATION BELOW AS GUIDELINE. **
• DO NOT LEAVE UNATTENDED WHILE CHARGING, & REMOVE CELL(s) FROM CHARGER ONCE FULLY CHARGED  to ensure it is not exposed to any potential charger malfunction such as overcharging which could damage cell causing it to explode.
• DO NOT CHARGE HIGHER THAN MAX CHARGE VOLTAGE (V)  ( typically 4.2V )  or  DISCHARGE BELOW MAX VOLTAGE CUT-OFF (V)  ( typically 2.5V ).  Overcharging or over-discharging cell(s) can cause irreversible damage and cause it to explode.
• DO NOT MIX WITH USED or DIFFERENT BATTERY TYPES . Differences in cell capacity can lead to one or more cell(s) being overcharged or over-discharged. 
• IF USING A MULTI-CELL DEVICE,  the device  MUST HAVE A NON-CONDUCTIVE BARRIER  ( typically plastic )  OR FITMENT  that  PREVENTS CELL(S)  from  TOUCHING THE SIDE(S) OF ONE ANOTHER OR ANY ADJACENT METAL  except for the very center of top and bottom of the cell. Otherwise, cell(s) could short-circuit and explode.
• ALWAYS  use, connect, charge, and operate cell(s) within their capabilities as listed on each cell, packaging, and product detail pages, while adhering to the device’s user manual.
• COMPLETELY READ  and follow the  WARNING  section listed on each cell, packaging, and here, in its entirety.
• SEARCH www.YouTube.com  for  “18650  EXPLOSIONS ”  to understand the importance of consistently taking safety precautions and using Li-ion cells properly.  Vapor Authority advocates recycling and replacing any damaged Li-ion cell/battery.  As a tool to find your  LOCAL RECYCLE CENTER .  Your safety is #1.

PLEASE BE SURE TO ALSO READ THE IMPORTANT SAFETY INFORMATION IN THE "HELPFUL TIPS" TAB BELOW.

Hohm Tech Hohm Work 18650 2531mAh Battery Specifications:

Manufactured By: Product of Indonesia Chemistry

Chemistry Type: Li-NiMn (Lithium Nickel Manganese)

Size: 18650

Battery Capacity: 2531 mAh

Battery Structure: Flat Top

Pulse Discharge Current: 40.6A

Maximum Continuous Discharge Current: 21.5A

Nominal Voltage: 3.7

Voltage at end of Discharge: max cut-off is 1.95V, but it is best to list “ 2.5V ” as 1.95V ages battery faster

Maximum Charging Current: 4.75A

Standard Charge: 2A

Charging Temperature Range: ideal between 10 o C – 40 o C (50F – 104 o F)

Discharging Temperature Range: ideal between 0 o C – 82.5 o C (32 o F – 180.5 o F)

Inner Resistance: ≤20mΩ

Length: 65mm (2.56 inches)

Diameter: 18mm (0.7 inches)

IMPORTANT SAFETY INFORMATION BELOW:

We strongly recommend that you do not hold batteries inside of your pocket along with other metallic items, such as keys or loose change. If the battery comes into contact with the metallic objects, it can potentially cause a short, which can be potentially dangerous. In addition, we recommend that batteries be stored separate from metallic objects. Housing them in a plastic container is a good practice, and is highly recommended.

Lithium-Ion batteries should only be purchased by adults 18-years-old or older. This battery is not intended for sale to minors under the age of 18-years-old.

Please take caution in purchasing a battery charger that is compatible with this specific battery type. Using an improper battery charger can be potentially dangerous.

Lithium-Ion (Li-Ion) batteries are made with a very different chemistry than conventional batteries. Although Lithium-Ion batteries are more powerful than conventional batteries, they do have more known risks, and can be extremely volatile and dangerous. Make sure to use caution when using and handling Lithium-Ion batteries.

Using an incorrect battery for your device can be potentially dangerous. Moreover, improperly using the correct battery can result in harm to your property or to your body. It is highly recommended that you use the appropriate batteries for your specific device, and that you are utilizing a suitable charger as well.

It is your responsibility to ensure that you know and understand the potential dangers of using Lithium-Ion batteries. We strongly recommend taking time to educate yourself as to the chemistry of, the potential hazards of, and the ways to avoid harm when using Lithium-Ion batteries prior to purchasing and using them.

We strongly recommend obtaining a minimum of 6 months’ experience prior to using Lithium-Ion batteries on your own. Please make sure that you have the adequate experience necessary prior to purchasing Lithium-Ion batteries.

By purchasing and using this product, you hereby consent to wholly taking full responsibility and sole liability for the purchase and use of this item. You further agree to hold harmless and indemnify Vapor Authority, its managers, executives, successors, shareholders, owners, employees, directors, and all affiliates from any and all liability for the usage of this product. Vapor Authority, Inc. is in absolutely no way, shape, or form liable for the harm or hazard that may arise due to the use of this product.

IMPORTANT SAFETY TIPS:

• In the event that the battery leaks, and substances such as electrolytes make contact with your eyes, make sure to avoid rubbing your eyes. Rather, immediately and thoroughly rinse your eyes out with fresh water and immediately call 911 to obtain proper medical attention, as this can cause severe permanent damage to your eyes.
• Make sure that you do not use or store Lithium-Ion batteries in very hot temperature environments. Make sure to avoid direct sunlight making contact with Lithium-Ion batteries, as this can cause the battery to overheat and leak.
• If you notice any sort of odor emitting from a Lithium-Ion battery, discontinue use immediately and discard it appropriately. If you notice the battery becoming very hot to the touch, discontinue use and discard the battery appropriately. If you notice any discoloration from the battery, discontinue use and discard the battery appropriately. In the battery appears to be warped, deformed, buckled, or otherwise misshapen, cease using it immediately and discard it appropriately.
• Do not use this battery in conjunction with other primary batteries, such as dry-cell batteries, that are of varying capacities, types, or brands.
• Avoid allowing the battery to be physically shocked in any severe fashion, such as throwing it or allowing it to drop onto the floor. In the event that this occurs, make sure to physically inspect the battery for any damage. If any is noticed, appropriately discard the battery and do not use it.
• Never puncture, stab, or otherwise penetrate any battery. Never attempt to open any battery. Doing so will expose the internal chemicals and is extremely dangerous and hazardous.
• Do not allow any battery to be submerged in water, or otherwise made wet. If your battery has been made wet, discontinue use and discard it appropriately.
• When charging Lithium-Ion batteries, do not remove the battery from the charger while the charger is plugged in. Rather, first unplug the charger, then remove the batteries.
• Make sure that your batteries do not come into contact with metallic objects, as this can be dangerous.
• If you will not be using your device for extended periods of time, make sure that you remove the battery from your device prior to storing it.
• Make sure that your batteries are stored in a moderate climate, such as standard room temperature.
• Make sure to read manufacturer charging instructions prior to charging any battery.
• Never connect wires or any metallic object to either the positive or negative pole of any battery, as this can cause a short and be extremely dangerous.

Customer Reviews

I bought two sets and the hold a charge okay. I bought another brand and I can go two days without charging them. They work but there’s others out there that work a little better. I bought them because at the time I didn’t want to go too another site to get the batteries and they came at a different date. They will work for what they are.

I saw all of the great reviews for these batteries, and bought 4 of them. 2 of them only hold a charge for about 2 hours and the other 2 hold a charge for almost 4 hours. My old batteries last longer than these. Maybe it is just the ones that I got. I am vaping at 9w with a 1.0ohm coil. My previous batteries before would last all day, and I did not change them until before I went to bed. I gave a 3 rating, because I am a huge fan of Vapor Authority, and they are an excellent vendor!

battery work great

AUTHENTICITY YOU CAN COUNT ON

We are proud to carry 100% authentic products direct from the top manufacturers in the industry. We guarantee all products we carry to be genuine and you can rest assured nothing you receive from us will ever be a clone or knockoff.

CUSTOMER SERVICE IS OUR TOP PRIORITY

We take customer service very seriously and will do our best to keep our customers happy. Send emails to [email protected] or call 888-927-VAPE to report problems or concerns. We also invite our customers to send suggestions or requests for any product we may not currently carry.

QUALITY WITHOUT ANY COMPROMISE

We strive to carry the finest vaporizing products at the lowest prices available. Our products are tried and tested by experienced "Vapers" who have taken the time to sift through the countless products on the market.

Proud USA Company

Vapor Authority is an American company, headquartered in sunny San Diego, California. We purchase all of our products directly from the manufacturer or authorized distributor, and store them entirely in-house. Unlike many other retailers who are stationed abroad or drop-ship from China, when your order is placed with Vapor Authority, our team will process, package, and ship your order all from our San Diego location.

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Terms and conditions

                By checking out you are agreeing that you are of legal smoking age in the state which you reside. You further agree that you will keep all of the products purchased through the Vapor Authority, Inc. website out of reach of children and minors below the legal smoking age in the state which you reside. Nicotine is harmful to ingest in any form or fashion, particularly if you are pregnant or nursing. DO NOT use any electronic cigarette product, even those with no nicotine, if you are pregnant or nursing. Nicotine is also known to be an addictive substance.

BY CHECKING OUT, YOU AGREE TO INDEMNIFY AND HOLD VAPOR AUTHORITY, INC. THEIR OFFICERS, AGENTS AND EMPLOYEES HARMLESS FROM ANY AND ALL LIABILITY, LOSS OR DAMAGE YOU MAY SUFFER AS A RESULT OF CLAIMS, DEMANDS, COSTS, JUDGMENTS, DAMAGE TO HEALTH, AND/OR HARM TO ANY PART OF YOUR BODY ARISING OUT OF THE USE OF ANY AND ALL OF THE PRODUCTS PURCHASED FROM VAPOR AUTHORITY.

BY CHECKING OUT, YOU AGREE TO INDEMNIFY AND HOLD VAPOR AUTHORITY, INC. THEIR OFFICERS, AGENTS AND EMPLOYEES HARMLESS FROM ANY LIABILITY, LOSS OR DAMAGE YOU MAY SUFFER AS A RESULT OF FIRE, DAMAGE TO ANY AND ALL PROPERTY, AND ANY AND ALL LOSSES THAT MAY RESULT FROM THE USE OF ANY AND ALL PRODUCTS PURCHASED THROUGH VAPOR AUTHORITY, INC.

WARNING : LI-ION BATTERIES HAVE INHERENT RISKS IF MISUSED or MISHANDLED. THEY CAN EXPLODE CAUSING SEVERE BURN, INJURY, FATALITY, and/or PROPERTY DAMAGE.

ALWAYS KEEP ALL BATTERIES OUT OF REACH OF MINORS AND PETS.

DO NOT PLACE BATTERIES NEAR A FIRE, AN OVEN, A MICROWAVE, OR EXPOSE IT TO ANY TEMPERATURE OVER 100 °C ( 212 °F).

DO NOT CARRY OR STORE BATTERIES OUTSIDE OF ITS PROTECTIVE PACKAGING OR PROTECTIVE CELL BASE.

DO NOT CARRY BATTERIES IN YOUR POCKET, BAG, OR PURSE.

DO NOT STORE BATTERIES OR BRING THEM IN CLOSE PROXIMITY TO ANY METAL OBJECT, INCLUDING COINS AND KEYS. DOING SO CAN SHORT-CIRCUIT THE BATTERY, CAUSING EXPLOSION, COMBUSTION, AND/OR FIRE.

DO NOT CARRY ANY DEVICE THAT CONTAINS A BATTERY IN YOUR POCKET OR ON YOUR PERSON. THE DEVICE MAY MALFUNCTION AND/PR SHORT-CIRCUIT, CAUSING AN EXPLOSION, COMBUSTION, AND/OR FIRE.

DO NOT EXCEED THE MAXIMUM CELL WATTAGE OR AMPERAGE LISTED ON THE BATTERY OR PACKAGING. DOING SO MAY OVERLOAD THE BATTERY CELLS AND CAUSE IT TO COMBUST, EXPLODE, AND/OR CATCH FIRE.

DO NOT USE AN OHM RESISTANCE LOWER THAN SPECIFIED ON THE BATTERY AND/OR PACKAGING.

DO NOT USE A BATTERY THAT SHOWS ANY SIGN OR DAMAGE TO ITS STRUCTURE OR  PROTECTIVE OUTER LABEL/WRAP/SLEEVE/SKIN. THIS INCLUDES ANY AND ALL DENTS, TEARS, NICKS, PUNCTURES, CORROSION, OR ANY AND ALL OTHER ABNORMALITIES OR UNDISCLOSED DAMAGE.

DO NOT LEAVE ANY BATTERY UNATTENDED WHILE CHARGING.

REMOVE BATTERIES FROM THE CHARGER AS SOON AS THEY HAVE BEEN FULLY CHARGED TO ENSURE THAT THE BATTERIES ARE NOT EXPOSED TO ANY POTENTIAL CHARGER MALFUNCTIONS, SUCH AS OVERCHARGING.

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A Beginner's Guide To 18650 Battery

by Genius Sky May 14, 2021 14 min read

Quick Links

What Does 18650 Mean

How to calculate the battery runtime, working principle of lithium-ion battery.

• Construction of lithium-ion battery

Reasons behind the safety issues with lithium-ion batteries

Difference between flat top and button top, unprotected battery, protected battery, battery sellers should ensure that customers use them properly.

Just like other lithium-ion cells,  the 18650 battery is named after dimensions.

The first two numbers(18) refer to the diameter of the battery in millimeters.

The next two numbers (65) stand for the height, and the final number (0) means the shape of the battery.

In this case:

• 18mm Diameter
• 65mm Height
• 0 Shape (Cylindrical)

What is voltage

Voltage , or electrical pressure, is the difference in electric potential between two points.

We can think of the 18650 battery as a bucket of water.

Water level, indicating the height of the water, is somehow very similar to voltage.

Because they are both used to gauge the range, difference between the lowest and highest.

When the water is consumed, the water level declines. After refilling, the water level rises.

So you know that voltage decreases when the battery is running/discharging, and increases again when the battery is being charged.

Nominal voltage

The voltage of 18650 lithium battery doesn't decrease evenly.

It begins at 4.2V and decreases slightly. It then drops rapidly to around 3.2V, until it stops working altogether.

From the graph, you can see that most of the time, it remains at around 3.7V midway through the discharging cycle.

Nominal voltage is often the midpoint of that range. 

Cell manufacturers mark the nominal voltage of their lithium-ion as 3.6V or 3.7V.

For marketing purposes, some manufactures would mark it as 3.7V on the package to imply that it's more powerful.

Why nominal voltage is 3.7V

You may wonder, why the nominal voltage of a 18650 battery has to be 3.6V or 3.7V.

Why isn't it 1.1V, 2.3V, or any other arbitrary number?

The nominal voltage is a function of anode and cathode materials, as well as impedance .

This sentence sounds complicated to understand.

Let's put it this way.

Nominal voltage depends on the chemistry of the battery.

Battery chemistry and their nominal voltage

For lithium-ion batteries, the mid-way point is between 3.6V to 3.7V.

This value varies among other types of batteries.

Why it needs to increase battery voltage

You have a 3.7V 2600 mAh 18650 battery cell.

You use it to power a 5V, 3W clip on fan.

However, the 3.7 voltage is not sufficient to power those devices that require 5V or more.

What does this mean?

Here comes the water bucket analogy again.

Let's suppose you want to spin a small waterwheel because you enjoy watching the rotation.

In the figure below, you can see this waterwheel contraption. It has a bucket sitting next to it with a tap halfway down.

The jet of water doesn't reach a high enough height to push the waterwheel.

We move the same quantity (or volume) of water to a slimmer and taller bucket. This allows the water level to increase.

This allows it to work, and the little waterwheel will spin as you wish.

You have a 3.7V 2600mAh battery, and you are expecting it can power a 600mAh fan for 4 hours or more.

2600mAh / 600mAh = 4.3 h

This calculation seems straightforward, but it's not correct.

Let's go back to the water example.

One bucket has a wider base area. The other one is smaller in diameter.

But you can't say the first bucket holds more water depending on the size of the bottom area.

The water depth also counts, right?

What really matters is the total energy stored in the battery or, in other words, how much water is in the bucket.

So, here comes another unit, Wh.

What is Wh?

Wh is short for Watt Hours.

It describes the energy capcity or  capacity  do useful work stored in the battery.

Why battery capacity is given in mAh instead of Wh

If you are buying a replacement battery, you might see their capacity listed in mAh (milliamps hours).

"Wait. Didn't you just say Wh stands for battery capacity? How come all the battery capacity was marked in mAh?"

I know you must be confused right now.

Relax, the water bucket analogy will help you sort things out over and over again.

Imagine you are looking to buy a bucket online.

The product page only tells you the radius and height. They think you don't necessarily need to know the volume.

 When indicating battery capacity, the relationship between mAh and Wh is very similar to the radius and volume of a bucket.

If you take a closer look, you will find that battery capacity was actually given in 3.7V 2600mAh .

It's like telling you how high(3.7V) and how wide(2600mAh) this product is.

How to convert mAh into Wh (Watt Hours)

 While mAh only suggests "two dimensions" of capacity, Wh is a solid "three dimensions" figure that calculates battery capacity as a whole.

Ah * V = Wh

You may not have heard of AH before.

Don't feel stressed about another unknown terminology.

Ah is just a different unit that is equal to 1000mAh

For a 3.7V 2600mAh battery, the Wh will be:

2600mAh * 3.7V

2.6 Ah * 3.7V = 9.62 Wh

So now we know the energy of a 3.7V 2600mAh battery is 9.62Wh.

Like we said before, Wh is similar to the amount of water in the bucket.

So, what does W mean? 

While the term Wh is used to describe the energy stored in a battery, W is more frequently used to describe how much power (power is energy per unit of time) your device consumes.

Different appliances require different amounts of W (Watts or wattage)

Assuming there are 3 small waterwheels, the weight of their bodies differs.

To spin the wheel, the heaviest one requires a strongest jet of water.

The other two wheels are lighter, which means less water is needed to get them to continuously spin.

We can reduce water flow from the tap to prevent any waste.

If we think about the tap pushing out electricity instead of water, we could say it's delivering different numbers of Watts for different water wheels.

Now if the bucket was filled with 9.62 Wh of water, it could supply the heaviest waterwheel for one hour.

We would say this waterwheel consumes 9.62W.

Other waterwheels, however, only consume 5W and 2W.

To find out how long these waterwheels keep spinning, just do the math:

9.62Wh / 9.62W = 1h

9.62Wh / 5W = 1.9h

9.62Wh / 2W = 4.8h

Now that you understand the terminologies of voltage, mAh, Wh, and wattage, it's time to calculate the battery runtime.

Battery doesn't run dry

We have used some examples like a 9.62Wh water bucket can supply the 2W waterwheel for 4.8 hours.

But that's not realistic.

You may have noticed that the water stops coming out when the water is level with the tap.

So, the bucket won't completely run out of water. 

The same applies to the battery.

It will disconnect the device at a certain voltage.

A 18650 battery is not supposed to run dry, or it will become permanently damaged (dead).

Conversion loss

As the amount of water remains the same, if you want to increase the height, you can simply move water from one bucket to another.

When it comes to batteries, you cannot literally change the "container". This is not how a battery works.

In reality, using a 3.7V battery to power a 5V device, a 3.7V to 5V boost converter required.

You can think of it as a pump.

As a working water pump requires energy, the 3.7V to 5V boost converter will consume battery power as well.

So, not all the battery energy is used by the device.

The boost converter also consumes battery energy.

During the conversion from 3.7V to 5V, you lose some battery energy.

The ultimate calculation

mAh is not a direct indicator of the stored energy. The first step is to calculate the battery energy Wh.

For a 3.7V 2600mAh 18650 battery , the Wh will be:

3.7V x 2600mAh

3.7V x 2.6Ah = 9.62Wh

Then, we take the conversion efficiency (assume, typically 65%) into consideration.

9.62Wh x 65% = 6.253Wh

We know the "realistic" battery energy is approximately 6.25 Wh.

Using the battery to power a 3W device, the runtime will be:

6.253Wh / 3W = 2.08h

That's approximately two hours of runtime.

Sometimes, you don't know the exact wattage of your device. Manufacturers put something like " 5V @ 0.6A " on the package instead.

No problem.

Based on the formula of A*V=W, you know the wattage is:

5V x 0.6A =3W

The below graph will help you organize the calculation process.

All batteries have the same three basic parts:

• a positive electrode called a cathode
• a negative electrode called an anode
• a chemical layer called an electrolyte

Generally, the positive electrode of 18650 cell is a metal oxide that contains lithium atoms.

The negative electrode is typically made from carbon, which has a layered structure, called graphite.

These layers are loosely bonded, so, lithium-ions can be stored easily between them.

Charge and discharge

During charging, there are lithium atoms are released from the metal oxide.

Because the lithium atom is highly unstable, it will instantly form a lithium-ion.

The electrolyte between the metal oxide and graphite acts as a guard which allows only lithium-ions to pass through.

After the lithium-ions flow through the electrolyte, they reach the negative electrode and get trapped there.

As soon as the power source is removed, this transportation goes in the opposite direction. Those lithium-ions will go back to the metal oxide.

Each lithium atom has only one electron. When a lithium atom transforms into lithium-ion, it will lose the electron.

Unlike lithium-ions moving back and forth through electrolytes, electrons move only through the external circuit. That's how electricity is generated.

Construction of a lithium-ion battery

In a practical 18650 cell, the metal oxide is coated onto aluminum foils.

The graphite is coated onto copper foils.

The foils are current collectors here with the positive and negative tabs attached to them respectively.

For safety reasons, a separator sheet is used to prevent contact between positive and negative electrodes.

So, there are basically three kinds of sheets. Positive electrode, negative electrode, and separators.

All these three sheets are wound into a cylinder around a center pin,  making the cell more compact.

For further protection, they are inserted into a stainless battery case.

Before sealing the case, separators and electrodes are filled completely with electrolyte.

Since the stainless battery case is a metal that conducts electricity, an extra insulating PVC wrapper is needed.

So, there are five major steps of the manufacturing process

• Coating the positive and negative electrode materials on metal foils
• Rolling the positive electrode, negative electrode, and separator
• Inserting the wound center pin into the battery case
• Sealing the battery case

Wrapping the battery with a protective cover

There have been many reported cases about the dangers of lithium batteries.

For example, there have been reports of fires in Tesla cars and exploding power banks in various other applications.

These serious safety issues were almost always caused by an internal short circuits.

How does an internal short circuit occur?

An internal short circuit can be triggered by various causes.

It sometimes happens because the separator in a battery melts due to overheating.

Without the protection of the separator, two electrodes could touch each other very easily, causing a short circuit.

Another cause of internal short circuits is the growth of dendrites.

Dendrites (from the Greek dendron meaning "tree"), form on the surface of an electrode.

They grow over repeated cycles of overcharging and over-discharging.

How lithium dendrites form?

(A) Charging: When charging a battery, the lithium-ions move from the cathode to anode.

(B) Overcharging: Numerous ions fill the anode. They are stuck in the graphite and unable to get out. If ions were trapped, electrons cannot be released. That's why the battery capacity is reduced. Since there is limited room in the graphite to accommodate lithium-ions, excess ions will begin to accumulate on the surface with nowhere else to go.

(C) Discharging: When discharge occurs in the battery, ions will return to the cathode.

(D) Over-discharging: The layered structure has a tendency to collapse as graphite when it contains only a small number of ions. The collapsed structure becomes less able to accommodate ions during the following recharging cycle. This problem makes overcharging more likely to occur.

• As noted in (B), ions pile up on the surface of an anode.
• Next, the accumulating ions begin to form metallic crystals.
• Then, dendrites branch out from the metal crystals to pierce the separators.
• The anode and cathode then touch each other.
• An internal short-circuit occurs, and a surge current follows within a few seconds.
• Large current flow happens, which leads to overheating.

Internal short circuits in Li-ion cells

Once the short-circuit happens, the damage is irreversible.

All the battery energy converts into heat. The voltage drops to zero. It won't hold a charge anymore, which leads to the premature replacement of a battery.

In conclusion, maintaining the good conditions of lithium batteries is very important.

Users should minimize the occurrence of dendrites by properly charging and discharging the battery. Making sure the battery is stored at moderate temperature is another practice to keep internal short-circuits from happening.

The battery's positive end is flat.

The battery's positive end is protruding.

Before you are trying to swap out the battery, look at the + pole.

Some devices, will only accept a flat top cell. 

As the flat top ones are slightly shorter, a button top will not fit in vaping devices, for example. 

Some brands of flashlights like Nitecore & Jetbeam, only work with button-top batteries. 

Aside from the size, it's also worth mentioning that  NOT all of the button top batteries are protected.

There are opinions like "the button top comes with a protected circuit, and the flat top is unprotected". 

This is not true.

Below, we will walk you through the terminologies for protected and unprotected batteries, and how to know which one is protected.

Unprotected battery. With this name, it sounds unsafe and acts like a buyer-repellent.

If that were the case, they will NOT be allowed in the market. So, how come there are so many unprotected cells out there?

Actually, unprotected battery has the PTC and CID, which means they are safe when properly handled.

PTC thermistor is a small disc that is found at the top of the battery.  

When the temperature rises, the resistance increases . 

If there is a surge current and the battery heats up significantly, the PTC will increase its resistance to limit the current. 

And then the temperature will drop normal, which prevents your battery from overheating.

When the battery is overcharged and the pressure inside becomes too high, the CID will disrupt the connection of the positive terminal . 

Imagine you are pumping air into a balloon. 

After it has reached the optimal level, you are still blowing air into the balloon. 

Guess what happens? It burst! 

CID, which is like a small hole (the pressure valve), works by releasing the gas through the hole. 

So, the "balloon" will slowly leak without causing an explosion.

What's the added benefit of protected cells

PTC and CID are built into the majority of 18650 batteries . They prevent the danger of fire and explosion. So, users are not exposed to the potential risks associated with batteries.

However, overcharge and over-discharge can still happen, causing damage to the battery itself.

PCB, the most advanced protection method, helps resolve the issue by detecting voltage above or below safe limits.

With the help of PCB, the battery will disconnect at a certain under, or over-voltage. 

It protects the battery against overcharging and over-discharging, assuring longer battery life.

Limit charge voltage , the maximum voltage of 18650 battery voltage, is 4.2V.

When charging the battery, the voltage keeps increasing.

Once the voltage reaches above 4.2V, it can be considered as overcharge.

Over-discharge

Cut-off voltage , the lower limit of a 18650 cell varies from 2.75V to 3V, depending on the specification.

It is recommended NOT to discharge the battery lower than 3V, just to be on the safe side.

You may know battery discharges when it connects to a device that needs power.

However, the chemical discharge reaction still happens, albeit relatively slowly, when the battery is not connected to any load.

This phenomenon is called self-discharge .

Self-discharging is not a manufacturing defect.

It occurs to all the batteries.

Although batteries stop connection with any devices when the voltage drops to around 3V, self-discharge will continue to consume the battery's energy.

As mentioned above, rechargeable li-ion batteries is charged and discharged by the movement of li-ions through the electrolyte.

At a very low voltage, the ions cease their movement entirely. That's usually why your device has trouble holding a charge.

You can run a lithium-ion cell totally flat and nothing dangerous will happen.

The thing is, once voltage decreases to the minimum limit, the lithium ions inside are not active anymore, and the cell cannot be recharged.

Sellers and manufacturers may ask you to recharge the battery every 3 months when it's not being used, which can help voltage remain at an optimal level.

If you are using the unprotected cells

Don't panic if you found your battery was the unprotected type when opening the battery compartment.

Modern devices are way smarter with managing power. 

Both your device and charger have built-in protection. 

They protect the battery against excessive charge and discharge conditions. 

That's why unprotected batteries are still being widely used in consumer electronics devices.

Some electronic hobbyists demand "raw" or unprocessed batteries to build their own battery packs. Besides, electronics manufacturers will purchase unprotected batteries from industrial distributors and design the protection circuit into the OEM products.

In all situations, PCB will be added to the device or the battery packs.

So, there's not really any reason to worry about it. The only danger comes from misusing these batteries and causing a short circuit. All you need to do is to use and maintain the device and battery properly.

However, don't ever think about adding PCB on your own. With limited knowledge about electrical engineering, most people don't know what they're handling.

Online sellers should use a pop-up disclaimer and help their customers making an educated purchase decision.

What is a protected battery

As mentioned above, a protected battery includes PCB protection.

How PCB works

1. Overvoltage: When the battery voltage reaches 4.35V, PCB makes it stop charging.

2. Over-discharging: PCB limits the voltage to 2.5V to prevent the battery from over-discharging.

3. Overcharging: PCB controls the maximum charge to, 3.4Ah (3400mAh, for an 18650 cell), which protects the battery against overcharging.

4. Short circuit: PCB works by preventing the flow of current. This method is kind of like the third one. But this time, it reacts much quicker (usually within 0.007 seconds) to the surge current.

How to tell your battery is protected

To identify if your battery is protected, check to see if there is a thin ridge under the plastic wrapper on the outside of the cell. This is a characteristic of a protected cell.

With a protected battery, you'll be able to feel the pole connecting the wire to the side of your battery. While the surface of unprotected battery appears smooth.

You can also identify a protected cell as it's generally longer than the unprotected version. This is due to the  PCB board attached to the cell bottom.

Finally, the bottom of a protected battery usually indicates its status.  It will differ in color from the main body.

If you are looking for a protected 18650 battery, check the spec. Reputable sellers should list this information on the product page.

Protected battery doesn't mean you are free of concern

The specific voltage of a working 18650 battery ranges from 3.2V to 4.2V

The voltage limit setting of PCB is 3V ~ 4.35V.

Unfortunately, this control system is not very precise.

PCB doesn't stop charging until the voltage reaches 4.35V. But the peak voltage of the battery should be 4.2V.

For the sake of longer battery life, don't leave it charging overnight. The advised charging time of one single 18650 cell in a typical charger is between 2 to 3 hours.

There are many dangerous goods on sale. But people are aware of the potential risks of those goods and take caution.

Cars can be dangerous. Therefore, there are driving license and traffic laws.

Excessive alcohol use can be dangerous. Thus, warning signs and education are required.

Most people seeing rechargeable lithium-ion batteries would probably assume they are normal batteries.

Few people know the danger of mishandling an unprotected battery.

Sellers should make customers aware of the correct use and the danger of incorrect use when it comes to lithium batteries or the devices that contain them.

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What is an 18650 Battery?

An 18650 Battery is a lithium-ion rechargeable battery. The first 4 digits of the designation “18650” indicate the physical dimensions while the 5 th digit indicates it is a cylinder cell. The standard 18650 battery is 18mm around by 65mm long. This type of battery is very common in applications such as laptop battery packs, flashlights, electric vehicles, cordless tools and various other devices that require portable power. Some types of 18650 have been modified adding either a button top and/or internal protection circuit. This can increase the physical length of an “18650” battery from 65mm to 70mm or in certain cases even longer.  If you're using an 18650 battery for a consumer product, you should always verify with that product's manufacturer for the exact specifications required to power the device.

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How Many 18650 Batteries to Make 1 kWh?

To calculate the number of 18650 batteries needed to make up 1 kilowatt-hour (kWh), you first need to know the voltage of a single 18650 cell, which is typically 3.6V or 3.7V. Then, convert 1 kWh to watt-hours (Wh), which is 1000 Wh. Using the formula Number of batteries=Total Wh required/(Voltage per cell×Capacity per cell (mAh)) , you can determine the number of cells needed.

For a 2600mAh cell, the calculation would be 1000/(3.7×2.6)≈97.2 , so you would need approximately 98 cells to reach 1 kWh.

• Battery Capacity: If each 18650 battery has a capacity of 2Ah and stores 7.4Wh of energy.
• Calculation: To create a 1kWh battery, you would need approximately 136 of these batteries.
• Parallel Connection: Connect the 136 batteries in parallel to achieve a 1kWh capacity.

How Many 18650 Batteries Would Make a 12V 20Ah Battery?

To achieve a 12V battery with a 20Ah capacity, you would (series) and (parallel) 18650 cells. Since a single 18650 cell has a voltage of around 3.6V to 3.7V, you would need 4 cells in series to reach 12V. To achieve 20Ah, you would then parallel the 4-cell packs. The number of parallel packs needed would be 20/2.6≈7.69 , so you would need 8 packs in parallel to reach 20Ah. This results in a total of 32 cells (4 cells per pack x 8 packs).

• Battery Capacity: If each 18650 battery has a capacity of 2500mAh.
• Calculation: To create a 12V 20Ah battery, you would need 24 batteries.
• Configuration: Connect the 24 batteries in a configuration of 3 rows of 8 batteries in parallel to achieve the desired capacity.

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The Ultimate Guide to the 18650 Battery

We get a lot of questions about the difference between rechargeable batteries and common one-time use batteries like AA & AAA batteries. Between different brands, strengths and confusing names, it can be easy to get lost when trying to research different types of rechargeable batteries and how to best care for them. We put together a complete list of our most frequently asked questions about 18650 batteries to help you understand how to get the very most out of your Fenix light and battery life.

What is an 18650 Battery?

An 18650 battery is a lithium-ion battery. The name derives from the battery’s specific measurements: 18mm x 65mm. For scale, that’s larger than an AA battery. The 18650 battery has a voltage of 3.6v and has between 2600mAh and 3500mAh (mili-amp-hours). (Osborne, 2019) These batteries are used in flashlights, laptops, electronics and even some electric cars because of their reliability, long run-times, and ability to be recharged hundreds of times over. 18650 batteries are what would be considered a “high drain battery.” This means that the battery is designed to generate high output voltage and current to meet the power demands of the portable device in which it is being used. Hence why these powerful little batteries are utilized in more complex, power-hungry electronics that require a constant, high level of power for operation. It also has a high depth of discharge, meaning that the battery can be drained all the way down to 0% and still have the capacity to fully recharge the battery. However, this is not recommended practice, as overtime this will cause long term damage to the battery and affect its overall performance. Learn more about caring for and enhancing the life of your 18650 later in the article.

History of the 18650 Battery

The lithium-ion battery was first invented in the 1970’s by an Exxon researcher named Michael Stanley Whittingham. His pioneering work to create the first version of the lithium ion battery then set in motion decades more research to finetune the battery to be as efficient and safe as possible. Then in 1991, a team of researchers and scientists named John Goodenough, Rachid Yazami, and Akira Yoshino worked together to develop and bring to market the lithium ion cell. The very first lithium ion battery cells were mass produced and sold by Sony. (Neverman et al., 2020) Since then, tweaks and enhancements have been made to extend the output and lifespan of the battery. Each of these changes resulted in a more efficient battery and in turn, a higher demand for their use and applications in the market. Today, lithium-ion batteries dominate the battery industry and have become ubiquitous in many household products we use everyday. There’s a very good chance you own many products powered by 18650 batteries, whether you realize it or not. As of 2011, lithium-ion batteries account for 66% of all portable rechargeable battery sales. (Osborne, 2019)

How a 18650 Battery Works

There are two types of 18650 batteries: protected and unprotected. As a rule of thumb, we always recommend using protected 18650 batteries. 18650 protected batteries have an electric circuit embedded within its packaging. This circuit protects the battery from “over charges” and “over discharges.” Both are situations you want to avoid. When a battery over charges, it can overheat, burst or catch fire.

It doesn’t take much imagination to understand how this malfunction can cause some serious problems for both the user and the manufacturer of the batteries. In fact, In 2016, Samsung released its newest smartphone, the Galaxy Note 7. It didn’t take long for reports to begin coming that the phones were exploding while charging. There had been a flaw in the design of the phone’s lithium ion battery that caused it to short circuit and catch fire.

Two separate recalls were put in place by the The U.S. Consumer Product Safety Commission, covering 1.9 million phones in the United States. Globally, to date, 96 percent of the 3 million phones that were sold have been returned. The debacle cost Samsung a pretty penny and a damaged reputation because of the number of fires and injuries the phones caused. It should be noted that the batteries within these phones were not specifically 18650, they were a larger, different type of 3500mAh lithium ion battery.

But for how widely used these batteries are, it seems like it is one of those easily overlooked technologies that we take for granted. From the moment we wake up to the moment we go to bed, there’s a very good chance we used some kind of 18650 battery. We don’t really realize how much they really do for us throughout our daily lives. Perhaps it’s because lithium-ion batteries are rarely seen on their own, instead they’re always encased inside the object they are charging. Not a lot of people take the time to consider how their electric toothbrush works, let alone how the batteries powering the toothbrush work.

There is actually a lot going on inside the battery’s tiny, colorful packaging. While the battery is being charged, the positive electrode lithium-cobalt oxide gives up some of it’s lithium ions which travel through the electrolyte to the negatively charged graphite electrode on the opposite side of the battery. The ions remain there until the battery is in use, during which the lithium ions travel back to the positive electrode, producing energy and powering the battery as it does so. In both the charging and discharging instances, electrons are flowing in the opposite direction of the ions around the outer circuit of the battery. (Osborne, 2019) The flow of ions through the electrolyte and electrons through the outer circuit are an interconnected process. One does not and can not happen without the other. Thus, should the battery completely discharge and the ions stop moving through the electrolyte, the electrons can’t make their way through the outer circuit and power is lost.

In the same way, should you turn off the object your battery is powering, the electrons will stop flowing through the circuit and so too will the ions. In essence, the battery stops discharging at a high rate. It should be noted that the battery will still continue to discharge at a very slow rate, regardless of whether the appliance is connected. Hence why you should always check the power level of your batteries every month or two in appliances that get more infrequent use.

What makes lithium-ions different from more simplistic batteries is their electronic controllers. These can be found only in the aforementioned “protected” batteries. Electronic controllers are built-in systems that regulate how the battery charges and discharges. It’s meant to prevent any overcharging or overheating that can, in some cases like the Galaxy Note 7 incident, cause lithium-ion batteries to explode. Using an unprotected lithium-ion battery can be tricky business to the uninitiated battery user. They are designed much more simply, meaning there is less of a chance for something to malfunction and are a bit smaller than protected batteries so they can fit into tighter spaces. However, the lack of protection opens the door to higher risks of overheating and explosion. Using unprotected batteries will, in general, yield the same performance but require more vigilance when it comes to charging and discharging.

Average Cost of a 18650 Battery

The cost of a 18650 battery can range widely depending on the brand, package size and whether it is a protected or unprotected battery. For example, the Fenix 18650 battery can range in price from $9.95 to $22.95 (these batteries are cheaper than most other brands when factoring in discounts), depending on the particular battery variation you are interested in. These batteries have a USB charging port right on the side of the battery itself, making recharging simple. They are at a bit higher price point than others because they are built with safety as a top priority, boasting three sets of overheating protection to prevent short circuiting so you can get up to 500 charge cycles out of a single battery without cause to worry about explosion or over discharging. Some unprotected batteries on the market can be found at cheaper prices, but as with anything you buy online, it’s important to factor in more to your purchase decision than just the price.

Pro Tip: As a general rule, if it seems too good to be true, it probably is. We suggest always buying any kind of technology, especially potentially dangerous ones like lithium-ion batteries, from a trusted source or name brand manufacturer.

Buying improperly manufactured or poorly made chemically-based products can yield unpleasant results, causing injury and destroying the appliance you were meaning to power. Before purchasing batteries online, it might be a good idea to check reviews from past customers or online tech forums to make sure you’re making a safe choice that also fits your power needs.

Different Types & Uses of 18650 Batteries

There are as many brands of 18650 batteries as there are uses. 18650 batteries are some of the most versatile on the market. They can be used to power just about anything, from electric cars to digital cameras.

As stated before, it is important to do your research beforehand when it comes to purchasing such potentially dangerous, though extremely useful products. Electric cars, such as the Tesla Model X and Model S , is what is known as a BEV, aka: battery electric vehicle.

These cars are powered by a hoard of lithium ion cells all working together. The Model S is powered by a battery pack that contains over 7,104 18650 cells capable of storing up to 85 kWh of energy. Recently, Tesla engineers have redesigned a new battery pack for their electric cars to hold 516 cells in each module for a total of 8,256 cells capable of storing a little more than 100 kWh of energy. This makes it possible for these electric cars to have a max range of over 300 miles on a single charge. It is a marvel to see how far scientists and engineers have come to in such a relatively short time. Everyday new improvements and enhancements are pushing the bounds of what this technology can do, how we think about electricity, and what role it will play in our everyday lives in the future.

How to Charge 18650 Battery

Depending on the brand of 18650 battery , you might need to charge your batteries as they were designed. But, for the most part, you don’t really need a specific type of charger or special cord to recharge your batteries – as long as it’s rated safe to charge lithium ion batteries. If you use a charger that is not meant for lithium ion battery types, it could result in, at best, permanent damage to your batteries and at worst, they could explode. Some batteries, such as the Fenix 18650 battery detailed above, actually are charged directly using simply a USB cord.

To get the very most out of your battery’s life span, we suggest making sure that your batteries are never fully discharged or drop too low in power if you can help it. Totally discharging the battery makes the ion transfer process much harder when it comes time to recharge the battery, thus limiting the capacity of the battery as a whole. The same is true for overcharging your batteries. Intaking too much power at once can put stress on the cells and cause damage in the long run. Instead, experts suggest “partial” charges to extend the overall lifespan of your batteries. While this does mean you might have to charge your batteries more often, it will save you time and money in the long run by helping you get the very most out of your existing batteries, saving you from the need to buy more.

How Long Do 18650 Batteries Last?

Most 18650 batteries have a life cycle of around 300-500 charge cycles. For example, Fenix batteries are rated for 500 cycles. This means that the battery will be able to fully charge to at least 80% of its initial capacity. Once it reaches that threshold, the battery’s “life cycle” is considered over. Though you can still probably get plenty more charges out of the battery, it’s capacity will slowly diminish further with time.

Most of us have all experienced this first hand when buying a new smartphone. Time and use will slowly diminish the battery’s life capacity, even with careful charging considerations. Extreme hot or cold temperatures can affect your battery life, as well.

Pro Tip: Make sure to never charge your 18650 batteries in below freezing temperatures! This can cause significant degradation and damage. For example, don’t leave your batteries to charge in a freezing garage in the winter.

How Long Does It Take to Charge a 18650 Battery?

The average 18650 battery takes about 4 hours total to charge. Of course, this can vary a bit based on the health of your battery and the type of charger you are using. To check the health of your 18650 battery, try to take note of how long it takes the battery to charge up, whether it is accumulating more heat than usual while it charges, if it is not producing as much power as it once did, or holding a charge as well. These are all indicators that your battery is reaching its end of life.

18650 Battery Storage Best Practices

18650 batteries need to be stored in a dry, room temperature space. Avoid any situations that might subject your batteries to either extreme cold or heat. Between the range of -20 to +50°C (-4°F to + 122°F) is sufficient but the most optimal storage temperature is somewhere around 77°F or 25°C. If you are planning on storing your batteries over a long period of time, it is actually better to have them charged at around 50% rather than 100%. This will help extend the lifespan of your batteries over time. Make sure to remove the batteries from it’s application before long term storage. For example, if you use your rechargeable batteries in a flashlight, take them out to be stored separately.

Pro Tip: Never store batteries in a pocket or bag that also includes any metal items such as keys, pins, or coins. This might cause accidental discharge. (battery & Instructables, 2017)

How to Discard Batteries Safely

Once your 18650 battery has reached the end of its life span, it is important to dispose of them responsibly. Never simply through these batteries into the trash! Though lithium ion batteries do not contain as many of the dangerous chemicals as other batteries, they still are considered hazardous waste and can cause fires or leak harmful chemicals into the earth. Many electronic or home improvement stores will have battery drop off zones or hazardous waste collection bins where you can get rid of your dead batteries without potentially causing environmental damage. Stores or collection centers will then send these batteries to recycling centers where they can harvest the metals inside to be reused. This is the most environmentally-friendly and economical way to dispose of old, damaged, or leaking batteries.

Rechargeable Batteries, Accessories and Flashlights

If you are in the market for a new rechargeable battery, flashlight or accessory. Fenix Lighting has been a trusted leader in rechargeable lighting solutions for decades. We offer state-of-the-art lithium-ion battery technology. Our rechargeable batteries and lighting solutions provide some of the very best in efficiency, performance, and lifespan in the industry. With thousands of satisfied customers and counting, our customers and fans come back to us again and again because they know when they buy Fenix, they are getting reliable, quality products backed by a full guarantee. Give our lineup a look or feel free to contact our friendly customer service line for recommendations or advice.

Source Cited:

Osborne, O. (2019, September 09). Where did the Lithium Ion battery come from? – 18650UK. Retrieved January 25, 2021, from https://18650.uk/where-did-the-lithium-ion-battery-come-from/

Neverman, A., Says, G., Grammyprepper, Says, A., Says, D., Smith, D., . . . Alonso, R. (2020, October 28). Everything You Need to Know About the 18650 Battery. Retrieved January 25, 2021, from https://commonsensehome.com/18650-battery/#:~:text=18650%20protected%20batteries%20have%20an,over%20current%20and%20short%20circuit

Understanding Tesla’s lithium ion batteries. (n.d.). Retrieved January 25, 2021, from https://evannex.com/blogs/news/understanding-teslas-lithium-ion-batteries

Battery, 1., & Instructables. (2017, September 29). How to Prolong the Life of an 18650 Battery. Retrieved January 25, 2021, from https://www.instructables.com/How-to-Prolong-the-Life-of-an-18650-Battery/

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DIY Professional 18650 Battery Pack

Introduction: DIY Professional 18650 Battery Pack

The world is shifting away from fossil fuels and will one day become fully electric. In the present world, Lithium-ion is the most promising chemistry of all batteries. Most of the battery packs used in Laptops, RC Toys, Drones, Medical devices, Power tools, e-bikes, and electric cars (EV) are based on 18650 batteries. It is one of the most mature Li-ion formats available, is produced in high volume, and enjoys a low cost per Wh.

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The 18650 (18mm diameter and 65mm length ) battery is a size classification of lithium-ion batteries. It is the same shape, but a bit larger than a AA battery. AA batteries, by comparison, are sometimes called 14500 batteries because they have a 14mm diameter and 50mm height.

Earlier I have made a Solar Power Generator which is working really nice till now. But the main problem is its weight, it is really heavy. The main weight of the Solar Generator is due to the heavy lead-acid battery inside it. So I decided to make a light and compact 18650 Li-Ion Battery Pack.

In this Instructable, I will show you, how to make a 18650 battery pack for applications like Power Bank, Solar Generator, e-Bike, Power wall etc. The fundamental is very simple: Just to combined the number of 18650 cells in series and parallel to make a bigger pack and finally to ensue safety adding a BMS to it.

At the end of this project, I made a custom 3D printed enclosure for the battery pack.

Disclaimer: I cannot be held responsible for any loss of property, damage, or loss of life if it comes to that. This tutorial was written for those who have knowledge of rechargeable lithium-ion technology. Please do not attempt this if you are a novice. Stay Safe.

Step 1: Parts and Tools Required

Parts Required:

1. 18650 Battery ( GearBest / Amazon )

2. BMS ( Banggood / Amazon )

3. Ni Strips ( Banggood / Amazon )

4. Battery Level Indicator ( Banggood )

5. Rocker Switch ( Aliexpress / Banggood )

6. DC Jack ( Banggood / Aliexpress )

7. 18650 Battery Holder ( Banggood )

8. 3M x 10mm Screws ( Banggood / Aliexpress )

1. Spot Welder ( Banggood / Amazon )

2. 3D Printer ( Creality CR10S )

2. Wire Stripper/ Cutter ( Amazon )

3. Hot Air Blower ( GearBest )

3. Multimeter ( Amazon )

5. Li Ion Charger ( GearBest )

Safety Equipment :

1. Safety Googles ( Amazon )

2. Electrical Gloves ( Amazon )

Step 2: Selecting the Right 18650 Cells for the Battery Pack

You will find many types of 18650 cells in the market in the price range of $1 to $10, but which are the best? I will highly recommend buying 18650 cells from branded companies like Panasonic , Samsung , Sanyo , and LG . These cells that have well-documented performance characteristics and excellent quality control. Reputed brand 18650 cells are generally costly, but if you consider for long time use then they are worth having it.

Don't buy any cells with the word FIRE in the name like Ultrafire, Surefire, and Trustfire. In reality, these cells are just factory rejects, purchased by companies like Ultrafire and repackaged in their own branded cover. Many used batteries are rewrapped as new and white-labeled. They sell the battery by marking capacity up to 5000mAh, but in actual their capacity is between 1000 to 2000 mAh. Another major problem with these cheap 18650 cells is the high risk of explosion when overheated during the charging or discharging.

In this project, I have used green Panasonic 18650B cells of capacity 3400 mAh from GearBest .

Step 3: Choosing the Right Battery Strips

To make the battery pack, you have to connect the 18650 cells together by means of Nickel strips or thick wire. Generally, Nickel strips are widely used for this. In general two types of nickel, strips are available in the market: nickel-plated steel strips and pure nickel strips. I will suggest buying a pure nickel. It is a little bit costlier than nickel-plated steel, but it has much lower resistance. Low resistance means, less heat generation during the charging and discharging, which leads to longer useful battery life.

Nickel strips come with different dimensions and lengths. Choose the strips according to the current rating.

Step 4: Spot Welding Vs Soldering

You have two options two connect the 18650 cells together: 1. Soldering 2. Spot Welding

The best choice is always Spot welding, but Spot Welder is much costlier than a good quality Soldering Iron.

Soldering :

You should know why Spot welding is preferred over soldering, the problem with soldering is that you apply a lot of heat to the cell and it doesn’t dissipate very quickly. This enhances the chemical reaction in the cell which damages the cell's performance. Ultimately you will lose some capacity and life the cells.

But if you are not interested to buy a costly Spot Welder, you can solder the nickel tabs to the cell by following some precaution and tricks :

1. To minimize the contact time of your soldering iron on the cell, make sure the surface is scuffed up sufficiently and you use plenty of flux to allow for fast solder flow.

2. It is better to have a good quality high wattage ( min 80W ) iron with good thermal capacity so it can deliver the heat to the joint quickly so you don't have to hold the iron to the battery for ages and let the heat seep into it, causing damage to the battery.

Spot Welding :

The reason we spot weld because it securely joins the cells together without adding much heat to them. There are two grades of spot welders currently available in the market: hobby grade and professional grade. A decent hobby-grade Spot welder costs around $200 to $300, whereas a good professional grade may cost around ten times more. So I will suggest buying a hobby-grade spot welder from any online store like Banggood, Aliexpress, or eBay.I am using the SUNKKO 709A 1.9kw Spot Welder from Banggood.

Step 5: Check the Cell Voltage

Before connecting the cells in parallel, first, check the individual cell voltages. For paralleling the cells, the voltage of each cell should be near to each other, otherwise, a high amount of current will flow from the cell with a higher voltage to the cell with a lower voltage. This can damage the cells and even result in fire on rare occasions.

If you are using brand new cells, the cell voltage is near 3.5 V to 3.7 V, you can join them together without worrying much. But if you are going to use an old laptop battery, be sure the cell's voltage is nearly the same, otherwise, charge the cells to the same voltage level by using a good Li-Ion Battery Charger. I used my Nitecore SC4 Charger to charge all the 18650 cells before joining them together.

Step 6: Battery Pack Capacity and Voltage

To make the battery pack, you have to first finalize the nominal voltage and capacity of the pack. Either it will be in terms of Volt, mAh/ Ah, or Wh. You have to connect the cells in parallel to reach the desired capacity (mAh ) and connect such parallel group in series to achieve the nominal voltage (Volt ).

For this project let the requirement is: 11.1 V and 17 Ah Battery Pack

Specification of 18650 Cells Used: 3.7V and 3400 mAh

Capacity (mAh):

The desired capacity of the battery pack = 17 AH or 17000 mAh.

The capacity of each cell = 3400 mAh

No of cells required for parallel connection = 17000 / 3400 = 5 nos

Commonly cells in parallel are abbreviated in terms of ‘P’, so this pack will be known as a “5P pack”.When 5 cells are connected in parallel, ultimately you made a single cell with higher capacity ( i.e 4.2V, 17000 mAh )

Voltage(Volt) :

The desired nominal voltage of the battery pack is 11.1V.

The nominal voltage of each cell = 3.7 V

No of cells required for series connection = 11.1 /3.7 = 3 nos

Commonly cells in series are abbreviated in terms of ‘S’, so this pack will be known as a “3S pack”.

So we have to connect the 3 parallel groups (5 cells in each group ) in series to make the battery pack.

The final pack configuration is designated as a “3S5P pack” with a final specification of 11.1V,17AH.

Step 7: Assemble the 18650 Cells

From the previous step, it is clear that our battery pack is made up of 3 parallel groups connected in series ( 3 x 3.7V = 11.1V ), and each parallel group has 5 cells ( 3400 mAh x 5 = 17000 mAh). Now we have to arrange the 15 cells properly for making the electrical connection among them and with the BMS board.

Place the first parallel group of cells (5 nos) positive side up, then place the second parallel group negative side up, and then finally the last parallel group positive side up. For better understanding, you can see the above picture.

You can assemble the cells to make the pack by using hot glue or by using a plastic 18650 battery holder. I used plastic 18650 cell holders/spacers to assemble the 15 cells. The main advantages of using these cell holders are

1. You can make a custom pack of any size according to your requirement.It's like solving a puzzle.

2. It provides space between the cells, which allow fresh air to pass and the battery gets cooled easily.

3. It makes your battery pack solid and reliable.

4. It provides safety anti-vibration to your battery pack

Step 8: Spot Weld the Nickel Strips

Now it is time to know the procedure for using the Spot Welder ( I am talking about the Spot welder that I have used in this project). The Spot welder has three welding choices: fixed welding head, fixed welding head with foot switch, movable spot welding pen with the footswitch. I prefer to use the second option. Before welding, you have to prepare the nickel strips and welder.

Cut the nickel strips :

Lay your nickel strip on top of the 5 cells ( parallel ), ensuring that it covers all cells terminals, leave 10mm excess strips for connecting it to the BMS, and then cut it. For series connection cut small nickel strips as shown in the figure. You will need four long strips for parallel connection and 10 small strips for series connections.

Connect the first parallel group negative terminal to the positive terminal of the second group and then the negative terminal of the second group to the positive terminal of the third group.

Weld the Battery Strips :

This spot welder can be used to weld the pure nickel as well as nickel-plated steel strips. You have to adjust the welder pulse and current knob according to the thickness of the nickel strips.

For 0.15 mm nickel strips, press the pulse knob 4P and current knob to 4-5. Similarly for 0.2 mm nickel strip, press the pulse knob 4P,6P, and current knob to 7-8. Make sure the welding pen is compressed with the nickel strip and battery terminal, then press the footswitch. You will notice a small spark and two-dot mark on the strip.

Successful Welding :

You can check the weld quality by pulling on the nickel strip. If it doesn’t come off with hand pressure or requires a lot of strength, then it’s a good weld. If you can easily peel it off, then you have to increase the current.

Safety: Before starting the spot welding, always wear safety goggles.

Step 9: Adding the BMS

A battery management system (BMS) is an electronic system that manages a lithium battery pack and the main functionalities are

1. Monitors all of the parallel groups in the battery pack and disconnect it from the input power source when fully charged ( near 4.2V )

2. Balance all the cells voltage equally

3. Doesn't allow the pack from over-discharged.

The two important parameters required to buy a BMS are: i) Number of cells in series - like 2S / 3S / 4S

ii). Maximum discharge Current - like 10A/ 20A /25A /30A

For this project, I have used a 3S and 25A BMS board . These are the specifications of that BMS :

Overvoltage range: 4.25~4.35V ± 0.05V

Over-discharge voltage range: 2.3~3.0V ± 0.05V

Maximum operating current: 0~25A

Working temperature: -40℃ ~ +50℃

How to Connect?

Connect the BMS as shown in the wiring diagram. The BMS has four soldering pads: B-, B1, B2, and B+. You have to connect the first parallel group negative terminal bus to the B- and positive terminal bus to the B1. Similarly the third parallel group negative terminal bus to the B2 and positive terminal bus to the B+.

You can spot weld the nickel strips to the BMS or solder it to the PCB pad. I preferred to solder the nickel strips to the PCB for a sturdy connection. First, apply soldering flux to the PCB pads and end of the nickel strips. After that tin all the pads by applying a little amount of solder and then solder them together.

Credit: The wiring diagram is taken from the Banggood product page.

Step 10: 3D Printed Enclosure

The battery pack has all-around exposed nickel strips, to avoid any accidental shorting, I designed an enclosure for it. I used Autodesk Fusion 360 to design the enclosure for my battery pack. The enclosure has two parts: The main Body and top lid. You can download the.STL files from Thingiverse .

I used my Creality CR-10S 3D printer and 1.75 mm green PLA filament to print the parts. It took me about 6.5 hours to print the main body and around 1.2 hours to print the top lid.

My settings are:

Print Speed: 70 mm/s Layer

Height : 0.3

Fill Density: 100%

Extruder Temperature: 205 deg C

Bed Temp: 65 deg C

Step 11: Wiring the Components

Normally a standard battery has only two terminal for connecting the load and to charge the battery. Apart from this, I have added a battery level indicator, to see the battery level whenever required. I have used a 5mm DC jack ( 12V /3A ) for input/output, 3S battery level indicator module to see the battery status, and a rocker switch to ON/OFF the battery level indicator.

Now let's move on to the wiring of the components. I've prepared this simple wiring diagram for all the components. It's pretty simple! To insulate the conductive parts, I used heat shrink tubing.

Note: Don't solder the wires ( P+ and P- ) to the BMS before installing the components into the enclosure.

Step 12: Final Assembling

First, install the components into the respective slots in the 3D printed enclosure. You can see the above picture.

Solder the positive (red wire ) from the DC jack and Rocker switch to the P+ of the BMS, negative wires from the DC jack, and Battery level indicator to the P- of BMS.

Then apply hot glue at the base of the battery compartment, then secure the battery pack. So that it will seats firmly and prevent any loss of wire connections.

Finally, screw the top lids in place! I used 3M x 10 screws for securing the lid. Now the battery pack is ready to use.

Charging the Battery Pack :

You can charge the battery pack by a 12.6V DC adapter like this . You can get it easily from aliexpress or eBay.

Hope you enjoyed reading about my project as much as I have enjoyed building it. If you’re thinking about making your own I would encourage you to do so, you will learn a lot. If you have any suggestions for improvements, please comment below.

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18650 Battery Capacity Chart

by Phil Borges // in Articles

Are you looking for the perfect 18650 battery for your device, but you’re not sure which one to choose? Don’t worry; we’ve got you covered. In this guide, we’ll take a closer look at the 18650 battery capacity chart, and help you choose the perfect battery for your needs.

What is the highest capacity 18650 battery?

The highest capacity 18650 batteries in the market are the 3500mAh 18650s. These batteries are perfect for high-drain applications such as vaping, flashlights, and power banks. However, it’s important to note that higher capacity batteries often have a lower discharge rate, meaning they might not be suitable for devices that require a high discharge rate.

How do you calculate 18650 battery capacity?

Calculating the capacity of an 18650 battery is relatively simple. All you need to do is multiply the voltage of the battery by its amp-hours (Ah) rating. For instance, a 3.7V battery with an Ah rating of 2.5 will have a capacity of 9.25Wh.

What is the max wattage for 18650?

The maximum wattage for an 18650 battery depends on its discharge rate. Typically, 18650 batteries with a high discharge rate of 20A or more can handle wattages of up to 80W, while those with a lower discharge rate might only handle wattages of up to 40W. It’s important to choose the right battery for your device to prevent overheating or other safety hazards.

Can 18650 batteries overcharge?

Yes, 18650 batteries can overcharge, and it’s important to avoid overcharging them to prevent damage to the battery or device. Fortunately, most 18650 batteries come with built-in protection circuits that prevent overcharging. However, it’s still a good practice to check your battery’s charging progress occasionally and remove it from the charger once it’s fully charged.

Choosing the right 18650 battery for your device can make a significant difference in your device’s performance and longevity. Make sure to consider factors such as capacity, discharge rate, and wattage when selecting your battery. And, always follow the manufacturer’s recommendations and best practices for charging and using your batteries to ensure your safety and the longevity of your device.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.

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Ultimate Guide to Building and Maintaining a 12v 18650 Battery Pack: Tips, Tricks, and Troubleshooting for DIY Enthusiasts

Discover how to build your own 12v 18650 battery pack with this comprehensive guide, covering everything from selecting cells to troubleshooting common issues. Boost your DIY skills and create a reliable power source for various applications.

Table of Contents

Introduction: the growing popularity of 18650 batteries.

In recent years, the 18650 battery has gained widespread popularity due to its versatility and impressive energy density. These rechargeable 3.7 volt batteries are commonly used in a variety of applications, from flashlights and power banks to electric vehicles and solar energy systems. As a lithium battery, the 18650 offers a perfect combination of portability and power, making it the go-to choice for many DIY enthusiasts and hobbyists. In this article, we’ll explore the world of 18650 lithium batteries, discuss their benefits, and guide you through the process of building your own 12v 18650 battery pack.

First, let’s take a look at why 18650 batteries have become so popular. These batteries offer several advantages over other types of batteries, such as their relatively high energy density, which allows them to store more energy in a smaller space. This makes them perfect for portable devices, such as flashlights and power tools, as well as larger applications like electric vehicles and solar energy storage systems.

The rechargeable nature of 18650 batteries also adds to their appeal. Unlike disposable batteries, which need to be replaced after they’re depleted, 18650 batteries can be recharged and used again, saving both money and the environment. In addition, the 3.7 volt output of these batteries provides enough power to run most devices, making them a versatile choice for a wide range of applications.

Another factor contributing to the popularity of 18650 batteries is the availability of various chemistries and capacities. Different 18650 cells, such as IMR, INR, ICR, and NCR, offer unique performance characteristics, allowing users to choose the best battery for their specific needs. Furthermore, the capacity of 18650 batteries can range from around 1800mAh up to 3600mAh, providing options for different power requirements.

Now that we understand the benefits of 18650 batteries, let’s dive into some popular brands and models. Well-known manufacturers like Samsung, Panasonic, Sony, and LG produce high-quality 18650 batteries that have been extensively tested for safety and performance. Some popular models include the Samsung 30Q, Samsung 25R, LG HG2, Panasonic NCR18650B, and Sony VTC6. These batteries offer a great balance of capacity, discharge rate, and reliability, making them excellent choices for various applications.

For those looking to buy 18650 batteries, finding a reputable 18650 battery store is crucial to ensure you’re getting genuine, high-quality products. Online retailers and local brick-and-mortar shops are good options for finding 18650 batteries near you. Just be sure to buy from a reliable seller to avoid counterfeit batteries and chargers.

So, how do you go about building a 12v 18650 battery pack? The process involves selecting the appropriate number of 18650 cells, a suitable charger, and a battery management system (BMS) to ensure safe charging and discharging. We’ll delve into the specifics of assembling a 12v 18650 battery pack later in the article, but it’s essential to have a basic understanding of the components and process before getting started.

In conclusion, the 18650 battery offers numerous benefits that make it a popular choice for a variety of applications. With its versatility, high energy density, and the availability of different chemistries and capacities, it’s no wonder that 18650 batteries have become a go-to option for many DIY enthusiasts and hobbyists. Whether you’re an experienced builder or just starting out, building your own 12v 18650 battery pack can be a rewarding project that will provide you with a reliable and powerful energy source for your devices.

Understanding the Basics: All About 18650 Batteries

Before we jump into the process of building a 12v battery pack, let’s take a closer look at what an 18650 battery is and why it’s become so popular. The 18650 is a cylindrical lithium-ion rechargeable battery, with a nominal voltage of 3.7 volts. Its name is derived from its dimensions: 18mm in diameter and 65mm in length. These batteries boast a high energy density, which makes them ideal for applications that require both power and portability.

While the 18650 battery is widely used, it’s not the only option when it comes to lithium-ion batteries. Other popular sizes include the larger 21700 and 26650 batteries. These variants offer even more capacity and power but come with an increased size and weight.

Now that we’ve covered the basics, let’s explore the different chemistries of 18650 batteries. Various chemistries, such as IMR, INR, ICR, and NCR, provide unique performance characteristics that cater to specific applications. For instance, IMR batteries are known for their high discharge rates and safety features, making them suitable for high-drain devices. On the other hand, ICR18650 batteries have a higher energy density but lower discharge rates, which makes them better suited for low-drain applications.

Understanding the terminology related to 18650 batteries is essential when selecting the right battery for your needs. The 3.7 volt rechargeable battery is a key component of 18650 battery systems, providing the necessary power for various devices. Moreover, the capacity of 18650 batteries is measured in milliampere-hours (mAh), which indicates the amount of energy the battery can store. Higher mAh values translate to longer runtimes for your devices.

Now that we’ve got a handle on 18650 battery basics, let’s discuss some popular brands and models. Some of the best 18650 battery options come from well-known brands such as Samsung, LG, Panasonic, and Sony. These companies produce high-quality, reliable batteries that have been extensively tested for safety and performance.

Some popular 18650 battery models include the Samsung 30Q, Samsung 25R, LG HG2, Panasonic NCR18650B, and Sony VTC6. The Molicel P26A and P28A 18650 2800mAh 35A batteries are also top contenders, known for their high discharge rates and reliability.

To find the right 18650 battery store or locate an 18650 battery near you, a quick online search should yield plenty of results. Just be sure to buy from a reputable seller to ensure you’re getting genuine, high-quality batteries.

Now that we have a better understanding of 18650 batteries, their chemistries, and the popular brands and models available, we can start exploring how to build a 12v 18650 battery pack. This process involves selecting the appropriate number of 18650 cells, a suitable 18650 charger, and a battery management system (BMS) to ensure safe charging and discharging.

In the following sections, we’ll delve deeper into the process of assembling a 12v 18650 battery pack, along with safety precautions and best practices to keep in mind. By the end of this article, you’ll have all the knowledge and tools you need to build your own 12v 18650 battery pack and power your devices with confidence.

Choosing the Best 18650 Battery: Comparing Brands and Models

With a plethora of 18650 battery options available, selecting the right one for your needs can be challenging. To make an informed decision, it’s essential to compare different brands and models based on factors such as capacity, discharge rate, and overall performance. In this section, we’ll guide you through the process of choosing the best 18650 battery for your 12v battery pack.

First, let’s discuss some of the top brands in the 18650 battery market. Reputable manufacturers like Samsung, LG, Panasonic, and Sony are known for producing high-quality, reliable batteries that have been extensively tested for safety and performance. These brands have established themselves as industry leaders, so you can trust their products for your battery pack.

Now, let’s dive into some popular 18650 battery models from these brands. The Samsung 30Q and 25R, LG HG2, Panasonic NCR18650B, and Sony VTC6 are all excellent choices, offering a balance of capacity, discharge rate, and reliability. Other noteworthy models include the Molicel P26A and P28A 18650 2800mAh 35A batteries, which are renowned for their high discharge rates and dependability.

To help you decide on the best 18650 battery for your needs, consider the following factors:

• Capacity: The capacity of an 18650 battery, measured in milliampere-hours (mAh), determines how much energy it can store. Higher capacities translate to longer runtimes for your devices. For example, a 3500mAh battery will provide more runtime than a 2500mAh battery.
• Discharge rate: The discharge rate, measured in amperes (A), indicates how much current the battery can deliver continuously. Higher discharge rates are necessary for high-drain devices, while lower discharge rates are suitable for low-drain applications. Be sure to choose a battery with a discharge rate that meets the requirements of your device.
• Battery chemistry: As mentioned earlier, 18650 batteries come in various chemistries, such as IMR, INR, ICR, and NCR. Each type has its advantages and drawbacks, so consider the specific needs of your application when selecting a battery chemistry.
• Price: While it’s essential to invest in high-quality batteries, you should also consider your budget when choosing an 18650 battery. Keep in mind that reputable brands may come with a higher price tag, but they often provide better performance, reliability, and safety.
• Availability: Some 18650 battery models may be more readily available than others, depending on your location. Be sure to choose a battery that you can easily find and purchase, either online or at a local store.

Once you’ve considered these factors, it’s time to find an 18650 battery store or locate an 18650 battery near you. A quick online search should provide you with plenty of options, but be sure to buy from a reputable seller to ensure you’re getting genuine, high-quality batteries.

In conclusion, choosing the best 18650 battery for your 12v battery pack involves comparing different brands and models, considering factors such as capacity, discharge rate, chemistry, price, and availability. By taking the time to evaluate your options and select the right battery for your needs, you’ll be well on your way to building a powerful and reliable 12v 18650 battery pack.

Assembling Your 12v 18650 Battery Pack: Step-by-Step Guide

Now that you’ve selected the best 18650 batteries for your needs, it’s time to start building your 12v battery pack. In this section, we’ll provide a step-by-step guide to assembling your 18650 battery pack, ensuring a safe and reliable energy source for your devices.

• 18650 cells (the number of cells will depend on your desired capacity)
• 18650 battery charger
• Battery Management System (BMS)
• Nickel strips or wire for connecting cells
• Heat shrink tubing or a battery holder for protecting and organizing cells
• Soldering iron and solder (if using wire for connections)
• Determine your battery configuration: To achieve a 12v output, you’ll need to connect your 18650 cells in series. This means connecting the positive terminal of one cell to the negative terminal of the next. For example, if you’re using 3.7v 18650 cells, you’ll need to connect four cells in series (3.7v x 4 = 14.8v) to achieve a voltage close to 12v. If you need more capacity, you can also connect cells in parallel, which involves connecting positive terminals to positive terminals and negative terminals to negative terminals.
• Assemble the cells: Start by arranging your cells in the desired configuration, paying close attention to polarity. Ensure that the positive and negative terminals are aligned correctly before proceeding.
• Connect the cells: Using either nickel strips or wire, connect the cells according to your chosen configuration. If using nickel strips, you can use a spot welder to attach the strips to the cell terminals. If using wire, carefully solder the wires to the terminals, taking care not to overheat the cells.
• Attach the BMS: A Battery Management System is essential for ensuring the safe charging and discharging of your battery pack. Connect the BMS according to the manufacturer’s instructions, making sure to connect the appropriate wires to the positive and negative terminals of the battery pack, as well as the balance wires to each cell group.
• Test your battery pack: Before sealing your battery pack, it’s crucial to test its performance. Using a multimeter, measure the output voltage of your battery pack to ensure it’s close to 12v. Also, test the charging and discharging functionality of the BMS to verify that it’s working correctly.
• Protect and organize your cells: To prevent short circuits and provide a clean, organized appearance, use heat shrink tubing or a battery holder to secure and protect your cells. Be sure to leave access to the BMS for future maintenance or troubleshooting.
• Charge your battery pack: Using your 18650 battery charger, fully charge your newly assembled 12v 18650 battery pack before using it in any devices.

By following these steps, you’ll be able to assemble a reliable and powerful 12v 18650 battery pack for your devices. Remember to practice safety precautions when working with batteries, and always use a proper 18650 charger to ensure the longevity and performance of your battery pack. Happy building!

Maintaining and Extending the Life of Your 12v 18650 Battery Pack

Once you’ve successfully built your 12v 18650 battery pack, it’s essential to maintain and care for it properly to ensure its longevity and optimal performance. In this section, we’ll provide tips and best practices for maintaining and extending the life of your battery pack.

• Use a suitable charger: Always use a reliable 18650 battery charger specifically designed for lithium-ion batteries. This ensures that your batteries are charged safely and efficiently, preventing overcharging or undercharging that could lead to decreased performance or even damage.
• Monitor the charging process: Keep an eye on your battery pack while charging and avoid leaving it unattended for extended periods. This allows you to address any issues, such as overheating or overcharging, that may arise during the charging process.
• Charge and store at the appropriate temperature: Lithium-ion batteries are sensitive to temperature fluctuations. To maximize battery life, charge and store your 12v 18650 battery pack in a cool, dry environment, ideally between 20°C and 25°C (68°F and 77°F).
• Avoid deep discharge: Allowing your battery pack to discharge too much can significantly reduce its overall life. To prevent this, aim to recharge your battery pack when it reaches around 20% of its capacity. The Battery Management System (BMS) should also help prevent over-discharge.
• Store partially charged: If you plan to store your battery pack for an extended period, it’s best to store it at a partial charge, ideally between 40% and 60% of its capacity. Storing it fully charged or fully discharged can shorten its lifespan.
• Periodically check and clean connections: Over time, dirt and dust can accumulate on the battery terminals, leading to decreased performance. Regularly inspect and clean the terminals with a dry cloth or a contact cleaner to ensure optimal conductivity.
• Balance the cells: Occasionally, the individual cells in your battery pack may become unbalanced, resulting in uneven charging and discharging. Use a balancing charger or the BMS to periodically balance the cells and ensure they’re all performing at their best.
• Replace worn-out cells: Like any other battery, 18650 cells have a limited lifespan and will eventually need to be replaced. If you notice that a particular cell in your battery pack is underperforming or has swollen, replace it with a new one to maintain the overall performance of your pack.
• Dispose of old batteries properly: When it’s time to dispose of your old 18650 batteries, don’t just throw them in the trash. Instead, recycle them at a designated battery recycling facility or drop-off location. This ensures the proper disposal of hazardous materials and helps protect the environment.

In conclusion, proper maintenance and care are crucial for ensuring the longevity and performance of your 12v 18650 battery pack. By following these tips and best practices, you can maximize the life of your battery pack, providing a reliable and efficient power source for your devices.

Safety Precautions When Working with 18650 Batteries

Working with 18650 batteries can be relatively safe if you follow the appropriate safety precautions. However, mishandling or improper use of these batteries can lead to dangerous situations. In this section, we’ll outline essential safety tips to ensure your DIY 12v 18650 battery project is both safe and successful.

• Use genuine, high-quality batteries: Always purchase 18650 batteries from reputable manufacturers and sellers. Counterfeit or low-quality batteries can pose a significant risk of failure, overheating, or even explosion.
• Inspect the batteries before use: Before using your 18650 cells, inspect them for any signs of damage or wear, such as dents, bulging, or leaking. Damaged batteries should not be used, as they can pose a safety hazard.
• Be mindful of polarity: When assembling your battery pack, ensure you connect the cells with the correct polarity. Reversing the polarity can lead to short circuits, overheating, and potential damage to the cells.
• Use proper tools and equipment: When working with 18650 batteries, use appropriate tools and equipment, such as a high-quality charger, a spot welder for nickel strips, and a soldering iron with temperature control. Using the wrong tools can damage the cells and lead to unsafe conditions.
• Avoid puncturing or damaging the cells: When connecting cells, be careful not to puncture or damage the outer casing. Puncturing a lithium-ion cell can lead to a short circuit, causing the battery to overheat, catch fire, or even explode.
• Keep a fire extinguisher nearby: Although it’s unlikely that your 18650 batteries will catch fire if handled correctly, it’s always a good idea to have a fire extinguisher nearby when working with them. Ensure the extinguisher is suitable for electrical fires (Class C in the US or Class E in other countries).
• Charge and discharge safely: Use a suitable charger and follow the manufacturer’s guidelines for charging and discharging your 18650 batteries. Overcharging, undercharging, or charging at extreme temperatures can lead to battery failure or damage.
• Monitor battery temperature: While charging or discharging your batteries, keep an eye on their temperature. If they become too hot to touch, immediately disconnect them from the charger or device and allow them to cool down. Overheating can cause irreversible damage to the cells and even pose a fire risk.
• Store batteries safely: When not in use, store your 18650 batteries and battery pack in a cool, dry place away from direct sunlight, heat sources, and flammable materials. It’s also a good idea to store them in a fireproof container, such as a LiPo-safe bag.
• Educate yourself: Familiarize yourself with the specific characteristics and safety precautions associated with 18650 batteries and lithium-ion technology in general. By understanding the potential risks and best practices, you’ll be better equipped to handle these batteries safely.

By following these safety precautions, you can minimize the risks associated with working with 18650 batteries and ensure a safe and successful DIY 12v 18650 battery project. Remember, safety should always be your top priority when working with any type of battery.

Expanding Your DIY Skills: Exploring Other Battery Types and Applications

Now that you’ve successfully built and maintained a 12v 18650 battery pack, you may be interested in exploring other battery types and applications for your DIY projects. In this section, we’ll briefly introduce some alternative battery types and their potential uses, as well as some exciting applications for DIY enthusiasts.

• 21700 battery: Similar to the 18650 battery, the 21700 battery is a cylindrical lithium-ion cell with slightly larger dimensions. These batteries offer higher capacities and discharge rates, making them ideal for high-power applications, such as electric vehicles and power tools.
• 26650 battery: The 26650 battery is another cylindrical lithium-ion cell with even larger dimensions than the 18650 and 21700. These batteries provide higher capacities and can be used in various high-power applications.
• Samsung 25R, 30Q
• Sony VTC5A, VTC6
• Panasonic NCR18650B, NCR18650PF
• Molicel P26A, P28A
• DIY power bank: With your newfound battery skills, you can create a custom power bank to charge your devices on the go. Combine your 18650 or other lithium-ion cells with a suitable charging circuit and USB output to create a portable power solution tailored to your needs.
• DIY solar energy storage: Harness the power of the sun by creating a solar energy storage system using lithium-ion battery packs. Pair your batteries with solar panels and a charge controller to create a sustainable and eco-friendly power source for your home or other applications.
• DIY electric vehicle conversions: If you’re feeling particularly ambitious, you can use your battery knowledge to convert a conventional vehicle into an electric one. By assembling a large battery pack and integrating it with an electric motor, you can create a custom electric vehicle that’s both environmentally friendly and fun to drive.
• DIY portable power stations: Create a portable power station using lithium-ion batteries to power your devices during camping trips, power outages, or other off-grid situations. Combine your battery pack with an inverter, USB ports, and other outlets to create a versatile and portable power solution.
• DIY e-bike or e-scooter: Convert your traditional bicycle or scooter into an electric one by building a custom battery pack and integrating it with an electric motor. This can make your commute more comfortable and efficient while reducing your carbon footprint.
• DIY home energy storage: Build a large-scale battery pack to store excess energy generated by your solar panels or wind turbines. This stored energy can then be used during times of low power production, such as nighttime or cloudy days, to power your home.

The possibilities for DIY projects involving batteries are virtually endless. With the skills and knowledge gained from building your 12v 18650 battery pack, you can expand your horizons and tackle more ambitious projects using different battery types and applications. So, get creative, have fun, and always remember to follow safety guidelines when working with batteries.

Troubleshooting Common Issues with DIY 12v 18650 Battery Packs

As with any DIY project, you may encounter issues or challenges when building and using your 12v 18650 battery pack. In this section, we’ll address some common problems and offer solutions to help you overcome these obstacles and keep your battery pack running smoothly.

• Battery pack not holding a charge: If your battery pack isn’t holding a charge, there may be a problem with one or more of the cells. Use a multimeter to test each cell’s voltage individually, and replace any that are underperforming or showing signs of damage.
• Overheating during charging or discharging: If your battery pack becomes excessively hot during charging or discharging, stop the process immediately and allow it to cool down. Overheating can be caused by damaged cells, poor connections, or a faulty charger. Inspect your battery pack, connections, and charger for any issues, and replace or repair as needed.
• Inconsistent battery performance: If your battery pack is performing inconsistently, it may be due to imbalanced cells. Use a balancing charger or the BMS to balance the cells, ensuring they all charge and discharge at the same rate.
• Voltage drop under load: If your battery pack’s voltage drops significantly when connected to a load, it could be due to high internal resistance or weak cells. Test each cell individually and replace any that are underperforming. Additionally, ensure that all connections are clean and secure to minimize resistance.
• Charger not recognizing the battery pack: If your charger isn’t recognizing your battery pack, double-check the connections between the charger and the battery pack. Ensure the polarity is correct and that there are no loose connections. If the problem persists, it could be due to a faulty charger or an issue with the battery pack’s BMS.
• Short battery life: If your battery pack’s life is shorter than expected, it may be due to low-quality or damaged cells, imbalanced cells, or an issue with the BMS. Test and replace cells as necessary, and balance the cells to ensure optimal performance.
• Swollen cells: Swollen cells can occur due to overcharging, over-discharging, or exposure to high temperatures. Immediately remove and replace any swollen cells, as they can pose a safety risk.
• Battery pack not providing enough power: If your battery pack isn’t providing enough power for your intended application, it could be due to insufficient capacity, high internal resistance, or weak cells. Consider upgrading to a higher-capacity battery pack, improving connections, or replacing weak cells to boost performance.

By identifying and addressing common issues with your DIY 12v 18650 battery pack, you can ensure its longevity and optimal performance. Remember to always follow safety guidelines when troubleshooting and working with batteries, and don’t hesitate to consult with experts or online resources if you’re unsure how to resolve a particular problem. With proper care and maintenance, your DIY 12v 18650 battery pack can provide a reliable power source for your projects and devices for years to come.

With over 20 years in I.T. and as a small business owner. I spend my days troubleshooting and repairing systems. I have worked for companies like Siemens, HP/ Compaq, Dell, and Xerox. I have services for all major brand PC and Macs. Service CNC and Computer Automated machines like industrial embroidery machines and the like. If it’s an electronic device, I will probably work on it. The best way to understand something is to break it open and look.

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18650 Battery Cells

Here is an 18650 battery next to AA, AAA, and CR123A batteries.

Specifications

18650 batteries can be charged with a compatible smart charger, while some feature a convenient Micro-USB or USB-C port.

Replacement Sizes

168A, 18650, 19670, Protected 18650, Unprotected 18650

What are 18650 Batteries?

The 18650 battery is a lithium-ion cell classified by its 18mm x 65mm size, which is slightly larger than a AA battery. They’re often used in flashlights, laptops, and high-drain devices due to their superior capacity and discharge rates. 18650s come in both flat and button top styles, and usually boast 300-500 charge cycles. Learn more about 18650 batteries here.

What does 18650 mean?

The term ‘18650’ refers to the measurement of the battery’s size in millimeters, in this case, 18mm x 65mm. It has a similar naming convention to other rechargeable lithium-ion batteries, such as 21700 and 16340 cells.

What uses 18650 batteries?

A host of devices use rechargeable 18650 batteries, including flashlights, laptops, power banks, and even electric cars! Here at BatteryJunction.com we offer a wide selection of flashlights that are powered 18650 batteries, found here.

How do I charge an 18650 battery?

18650 cells can be charged with a smart charger. Some have a built-in USB port, with either Micro-USB or USB-C functionality. Batteries with a built-in charge port may be a valued choice for your average flashlight user because they are quick and easy to recharge. We recommend using a smart charger for those charging multiple 18650 batteries, as many allow you to check capacity and select different charge currents.

How long do 18650 batteries take to charge?

On average, it takes 4 hours to charge an 18650 battery, depending on the battery health and charger type. Avoid fully discharging 18650 batteries when you can, as this limits the ion transfer process when recharging and can reduce the overall battery capacity. Overcharging the li-ion batteries can put stress on them, causing damage long-term.

How long do 18650 batteries last?

Typically, rechargeable 18650 batteries have a shelf life of 3 years with a life cycle of 300-500 charges! However, it’s worth noting that factors like extreme cold or heat can negatively affect the lifespan of an 18650 cell.

How can I tell if an 18650 is protected?

You can tell based on the inclusion of PCB protection. 18650 batteries with built-in PCB protection have an electronic circuit board in the battery that monitors performance parameters, which helps to prevent issues like over-draining, overheating, and short-circuiting.

Bare cells are both shorter and cheaper when compared to models with built-in PCB options, but require more caution when charging and discharging. If you’re new to using lithium-ion batteries or just simply need an 18650 for your flashlight, we highly recommend a battery with built-in protection.

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For questions, news, and discussion about batteries, cells, chargers, charger/inverters, power banks and UPSs.

Recommendations for high-capacity 18650 lithium cells from Aliexpress.

Hello, I am planning to make 13s6p a battery pack and have been looking for high-capacity lithium cells on Aliexpress. However I haven't purchased cells from Aliexpress ever, does anyone have suggestions for some that are actually reliable? I am looking to get cells with a minimum capacity of 3400 mAh, but more would obviously be better. Thanks.

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18650 battery recommendations for beginners?

Since the DevTerm requires 18650 batteries, I’ve been looking to get some before my Devterm arrives. I’ve never used 18650 batteries before, so I went to the forum to find more information. After some research, I realized that 18650 batteries are more complicated than regular batteries. I also realized that I don’t actually know where to start in terms of choosing batteries. Do any of you have recommendations or advice on which batteries I should get and where to buy them? Hopefully, seeing other’s opinions on this topic will help point me in the right direction. Thanks in advance for the help!

I researched a few different capacities… I may have bought to large a capacity not sure of capability with the charging circuit on the DivTerm but they are available on Amazon: 18650 Rechargeable Li-ion Battery 3.7V 9900mah Large Capacity Lithium Batteries Safe Accessories for LED Flashlight, Emergency Lighting, Electronic Devices etc. 4/8 Pieces (Yellow) (4 pcs) $13.98…(typically they are 3000 mah capacity…

Ther is a lot of info… and im giving you a lot to go thru… but it is my hope that after all this, you should feel al little more comfortable make a decision. If after all this study, you still have queries, I invite you to ask and we can start discourse.

can you name a few “trusted” sources please?

read everything in the two posts i linked and you would have found what you are looking for… unless you want me to buy you the batteries too…

i used the search feature to pull posts that already contained detailed answers and link them for you… the least you can do is read them…

From what I can gather from the video sources you kindly together here

[check] protected cells [check] capacity over 3800 mah fake…fake fake [check] purchase wrapped cells(naked cells are dangerous) - re-wrap repurposed cells - same theme as folks on power walls suggest [check] lipo batteries (18650) cells are dangerous - saw a video where someone put a nail through one and it lit off like fireworks (dont mishandle)

I prefer lipoFe batteries and have two power boxes (one I built) for two way radio/camping emergency that are 14.4 volts nominally - that’s the world I operate in…12, 24 and 90 volt DC nominal systems -

own numerous other consumer items with single cell lipo 18650 type cells they meet the criteria - not asking to be spoon feed here. just a short answer of trusted vendors… if Amazon is not a suitable vendor I guess I will watch all the videos and see who they recommend… Yes I know Amazon has counterfeit vendors (arduino comes to mind) (personal preference is Panasonic and LG brands for batteries we buy at work but these are typically NiCad and are used for industrial system memory backup) Rambling here but the goal is to have what is needed when the DevTerm arrives…

Okay my browser compacts your lengthy post… managed to expand the post where it discusses vendors, dimensions… would not suggest unwrapped batteries to someone who wants to just put a couple in the unit and turn it on. Absolutely suggest getting a model with some internal protection. Lipo batteries can dump a great deal of current if they are shorted as in (you put one battery in the wrong way…) The DevTerm uses the lipo battery because of the energy density and has a built in charger for the type of battery so read the articles and also how to care for batteries when not installed in the unit - don’t put in a junk drawer with keys and other metial objects if they short they can dump current fast… (even if current limited they can spark and cause a great deal of heat)

"battery guide (i actually get my batts from here) Best 18650 Battery | 18650 Guide - Comparison Chart – 18650BatteryStore.com "

Got the cells I ordered per your recommended technical articles today … ordered a modest 2000 mah capacity with the better safety protection and best match for the load demand (as far as I can guess)

Now all you gotta do is charge em up

Do we need to purchase an extra charger case for 18650 batteries for the new DevTerm? Can we charge them up while they’re inside the DevTerm with the type-c port of the device?

that would be one way… I personally do not know enough about the charging circuit to trust it 100% (as opposed to a dedicated circuit). Like how fast does the DT charge these cells? Does the DT have to be on to charge them? In the links posted above, I did go through the trouble to actually recommend a decent charger and why.

Let us see. battery types, sizes, ratings, knock-offs, chemistries, chargers, wrappers/labels, safety, rewrapping, protections, dangers… did we discuss storage yet? i mean yea, sure. DT, Charger… check… but… now hear me out… what if you got 8 cells? like me? you gotta store them and safely too, right?

I have something like this…

I’m closing this topic as there are already plenty about batteries for the DevTerm.

If you want continue the discussion please use this topic: Battery model recommendation

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What is an 18650 lithium battery?

Meet the 18650, a remarkable lithium-ion rechargeable battery that goes by the formal name 18650 cells. These batteries operate at a voltage of 3.7 volts and come with varying capacities, typically ranging from 1800mAh to 3500mAh (milliamp-hours).

Notably, the 18650s may exhibit a voltage spectrum spanning from 2.5 to 4.2 volts or a charging voltage of 4.2 volts. However, the standard nominal voltage for a typical 18650 cell is 3.7 volts.

Within this category, there exist two distinct types: protected and unprotected. It’s highly recommended to opt for the protected cell 18650 batteries. Protected cells incorporate a safety-protection circuit, ensuring they won’t be overcharged, thus bolstering safety.

On the flip side, unprotected cells lack this safeguard, which means they have the potential to be overcharged, leading to ruptures and, in extreme cases, fire hazards—unless specific electronics are in place to shield the battery. Notably, some popular models like LG HG2, INR, and Samsung 25r and 35e fall into the category of UNPROTECTED batteries, and they should only be used in devices designed to accommodate such cells.

Another essential consideration is the quality of the 18650 battery . Sticking with well-established brand names is prudent to avoid subpar imitations that might falsely advertise higher capacities (mAh).

Regarding recharging, the average 18650 battery requires around 4 hours for a full charge. However, this charge time can vary based on factors such as the amperage and voltage of the charger, as well as the specific battery type you’re using.

The 18650 battery represents a noteworthy advancement in rechargeable power. Still, it comes with critical nuances, including the choice between protected and unprotected versions, the importance of brand reliability, and the variable charge times based on charger specifications and battery type. Understanding these intricacies ensures a safe, efficient, dependable experience with the 18650 Marvel.

Table of Contents

Diverse Battery Dimensions Unveiled: A Visual Comparison

Below is an illustrative depiction of various battery sizes, each possessing unique cubic millimeter measurements. The 18650 battery occupies 1170 cubic mm, while the 14500 and AA batteries share a volume of 700 cubic mm, with the AAA battery compactly residing within 467 cubic mm.

It’s worth noting that while the 14500 battery resembles the AA size, it’s only universally compatible with some AA devices if those devices support both 3.7-volt and 1.5-volt batteries. A noteworthy distinction arises with the 21700 battery, taking up 1550 cubic mm, surpassing the 18650 battery in size—highlighting that the 21700 and 18650 are not interchangeable.

Now, let’s compare 18650 batteries with other commonly used battery types, considering essential attributes such as rechargeability, voltage, maximum milliamp hours (mAh), watt hours (Wh), and length and diameter measurements.

●  Nitecore 21700: Rechargeable, 3.7v, 5000 mAh, 18.5 Wh, L: 74mm, D: 21.4mm.

●  XTAR Li-ion 14500: Rechargeable, 3.7v, 800 mAh, 2.9 Wh, L: 50mm, D: 14mm.

●  Eneloop Pro AA: Rechargeable, 1.2v, 2550 mAh, 3.0 Wh.

●  Eneloop Pro AAA: Rechargeable, 1.5v, 950 mAh, 1.4 Wh.

As a point of comparison, a 12v car battery is included, showcasing its considerable capacity with 40,000 mAh and a remarkable 480 Wh. This comprehensive overview underscores the unique features of each battery type, making it easier to select the right battery for specific applications based on rechargeability, voltage, capacity, and size requirements.

Understanding 18650 Battery Terminology: Demystifying the Features

When faced with a battery labeled as “protected mode 3.7v 18650 3000 mAh low self-discharge for high-drain devices,” it’s essential to decode the meaning behind these specifications.

Protected Mode indicates that the 18650 battery possesses built-in safeguards against overcharging and excessive discharging through an embedded circuit within the battery casing, enhancing safety

3.7v : This value signifies the optimal voltage or the peak power output. However, as the battery is used, the voltage will gradually drop.

3000 mAh : This measurement denotes the battery’s capacity, expressed in milliampere-hours (mAh). A higher number is preferable, but it’s essential to note that the most realistic capacity available today for 18650 batteries is around 4000 mAh. Claims exceeding this value often lean toward marketing hype.

Low Self-Discharge:  This positive attribute indicates that the battery can retain its unused charge. Batteries with low self-discharge lose minimal charge during storage, ensuring more power is available for devices when needed, such as flashlights.

For High-Drain Devices : This specification signifies that the battery is optimized for high-drain devices, which consume power rapidly. Examples include RC toy cars and other devices with significant power requirements.

Now, let’s delve into the distinction between protected and unprotected 18650 batteries:

Protected 18650 Batteries:  These batteries feature an embedded electronic circuit within the cell packaging, offering protection against overcharging, overheating, over-discharging, overcurrent, and short circuits. Opting for a protected 18650 battery enhances safety, reducing the likelihood of overheating, bursting, or fire hazards.

Unprotected 18650 Batteries:  Although cheaper, we strongly advise against using unprotected batteries without external monitoring and control of load, draw, and charging. Typically, protected batteries have a “button top,” but it’s crucial to check specifications. Flat-top 18650 batteries generally lack the protection circuit.

If you encounter any damaged or corroded 18650 batteries or if they appear leaking, ensure proper disposal at a battery recycling center for safety.

Power Capacity of an 18650:

A typical 3.7v 3400mAh 18650 can store around 2 ampere-hours (aH) to a maximum of 3.5 aH, translating to approximately 10 to 13 watt-hours (Wh). To put this in perspective, a small air conditioning unit capable of cooling around 9000 BTUs consumes about 1100 watts per hour. Running this air conditioner for an hour would require over 110 of these 18650 batteries.

In comparison, achieving the exact power requirement using traditional car batteries would necessitate three 12v 40 amp car batteries. Notably, the compact size of 110 18650 batteries surpasses that of three car batteries while meeting the same energy demand. This highlights the remarkable energy density of these small but potent 18650 cells.

In the world of rechargeable batteries, the 18650 stands tall. It holds its charge, serves high-drain devices with excellence, and even plays a role in the sustainable future of energy storage. Though seemingly diminutive, its impact is substantial. It’s a reliable companion, powering flashlights, RC cars, and many other devices.

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Understanding the 18650 Battery: Everything You Need to Know

History of the 18650 battery, specifications and design, applications and usage, advantages of the 18650 battery, disadvantages of the 18650 battery, safety considerations, future developments and trends.

The 18650 battery is a powerful and versatile energy storage device that has become increasingly popular in recent years. From its origins to its specifications and applications, this article will provide a comprehensive understanding of the 18650 battery, along with its advantages, disadvantages, safety considerations, and future developments.

• 1 History of the 18650 Battery
• 2 Specifications and Design
• 3 Applications and Usage
• 4 Advantages of the 18650 Battery
• 5 Disadvantages of the 18650 Battery
• 6 Safety Considerations
• 7 Future Developments and Trends

The 18650 battery was first introduced in the 1990s by the Japanese company SONY. The “18650” designation refers to its dimensions: 18mm in diameter and 65mm in length. Originally developed for use in laptops, the 18650 battery proved to be highly efficient and reliable, leading to its adoption by various industries.

The 18650 battery is a cylindrical lithium-ion battery that has gained recognition for its outstanding performance. Here are some key specifications and design features:

• Voltage:  The 18650 battery typically operates at a nominal voltage of 3.7 volts.
• Capacity:  It comes in various capacity options, ranging from 1500mAh to as high as 3500mAh, providing long-lasting power.
• Chemistry:  The 18650 battery employs lithium-ion chemistry, which offers high energy density and low self-discharge rates.
• Protection Circuit:  Many 18650 batteries come with a built-in protection circuit to prevent overcharging, over-discharging, and short circuits.
• Rechargeable:  One of the significant advantages of the 18650 battery is its rechargeable nature, allowing for multiple uses and reducing waste.

The design and specifications of the 18650 battery make it suitable for a wide range of applications.

The versatility of the 18650 battery has led to its adoption in numerous industries. Here are some common applications and usage scenarios:

• Consumer Electronics : The 18650 battery is commonly used in devices such as laptops, power banks, flashlights, and electric scooters due to its high capacity and reliability.
• Electric Vehicles : Many electric vehicles, including electric cars, bicycles, and boats, utilize 18650 batteries as their primary power source.
• Renewable Energy Storage : The 18650 battery plays a vital role in storing energy from sources like solar panels and wind turbines, allowing for a more sustainable and efficient energy grid.
• Portable Electronics : From drones to handheld gaming devices, the 18650 battery provides a compact and lightweight power solution for various portable electronics.

The applications of the 18650 battery are vast and continue to expand as technology evolves.

The 18650 battery offers several advantages that contribute to its widespread popularity. Here are some notable advantages:

• High Energy Density : The 18650 battery provides a high energy density, allowing for longer battery life and efficient power delivery.
• Long Cycle Life : With proper care and maintenance, the 18650 battery can last for hundreds of charge-discharge cycles, making it a cost-effective choice in the long run.
• Wide Availability : Due to its popularity, the 18650 battery is widely available from various manufacturers, ensuring a steady supply for consumers.
• Compact Size : The cylindrical design of the 18650 battery makes it easy to fit into a variety of devices, enabling manufacturers to create more compact and portable products.
• High Discharge Rate : The 18650 battery can deliver high discharge rates, making it suitable for applications that require a burst of power.

While the 18650 battery boasts several advantages, it also has a few limitations. Here are some important disadvantages to consider:

• Limited Shape Options : The cylindrical shape of the 18650 battery may not be suitable for certain devices that require a different form factor.
• Higher Cost : Compared to other types of batteries, the 18650 battery can be relatively more expensive, especially when considering high-capacity options.
• Safety Risks : Mishandling or improper use of the 18650 battery can lead to safety hazards, such as overheating or explosion. Proper precautions must be taken to ensure safe usage.
• Self-Discharge : Like all lithium-ion batteries, the 18650 battery experiences self-discharge over time, meaning it will lose some capacity even when not in use.

It is essential to weigh the advantages and disadvantages when considering the use of the 18650 battery in different applications.

Safety is a crucial aspect when working with the 18650 battery. Here are some safety considerations to keep in mind:

• Proper Storage : Store the batteries in a cool, dry place to prevent overheating or leakage.
• Avoid Overcharging/Discharging : Overcharging or discharging the battery beyond its recommended levels can lead to safety risks. Follow the manufacturer’s guidelines and use dedicated chargers.
• Protection Circuits : If available, use 18650 batteries with built-in protection circuits to minimize potential hazards.
• Avoid Mishandling or Physical Damage : Avoid dropping, crushing, or exposing the battery to extreme temperatures to prevent internal damage.

Adhering to safety guidelines and using the 18650 battery responsibly is crucial for ensuring safe and efficient operation.

As technology progresses, the 18650 battery continues to evolve. Here are some future developments and trends to watch for:

• Increased Capacity : Manufacturers are continually striving to improve the capacity of the 18650 battery, providing even longer-lasting power.
• Enhanced Safety Features : Advancements in safety mechanisms, such as improved protection circuits and thermal management systems, will likely reduce safety risks associated with the 18650 battery.
• Alternative Chemistries : New chemistries, such as lithium-sulfur or solid-state batteries, may eventually replace or complement the traditional lithium-ion 18650 battery, offering even higher energy densities and improved safety profiles.

The future of the 18650 battery looks promising, with ongoing research and development focusing on addressing its limitations and maximizing its potential.

In conclusion, the 18650 battery has become a crucial component in various industries due to its exceptional performance and versatility. Understanding its history, specifications, applications, advantages, disadvantages, safety considerations, and future developments is essential for making informed decisions when utilizing this powerful energy storage device. As technology progresses, it is likely that the 18650 battery will continue to play a vital role in powering our ever-advancing world.

Are you looking to learn more about Lithium Batteries and electrical systems? We understand how difficult it can be to build or upgrade an electrical system, so we’re here to assist. Reach Our sales and customer service team at the contact page. 

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What is the valid capacity ranges of Lithium Ion 18650 batteries?

I'm seeing wildly varying capacities that are seemingly fake on 18650 cells, such as these "9,800 mAh" ones on eBay , but are ~$1 / cell.

However, 'genuine' cells from Panasonic and similar name brands seem to top out around 3,500 mAh or so, but cost more like $8 / cell.

How can I tell true capacity apart from the lies?

• lithium-ion

• 1 \$\begingroup\$ If it looks too good to be true, it's too good to be true! Don't buy eBay low cost electrolytic capacitors either. \$\endgroup\$ –  Neil_UK Commented Mar 1, 2016 at 9:57
• \$\begingroup\$ Sure, but the capacities will rise gradually; how do I know what 'too good' is referenced against? \$\endgroup\$ –  Ehryk Commented Mar 2, 2016 at 4:51
• 1 \$\begingroup\$ I don't think there is anything reputable over 3.5Ah. If you need to discharge rapidly (e.g., 10A or more) you want to get cells specifically designed for rapid discharge. Those will have slightly lower capacity. I think 3Ah is the current max in rapid discharge. 2.5, 2 and even 1.5Ah cells are still out there and are available. Buy from a reputable vendor! \$\endgroup\$ –  user57037 Commented Aug 1, 2017 at 5:48
• \$\begingroup\$ 18650 battery tests 2011 2012 \$\endgroup\$ –  Bruce Abbott Commented Aug 1, 2017 at 6:11
• \$\begingroup\$ I came to this question from google looking for an actual answer to what are the valid capacity ranges for 18650 lithium ion cells \$\endgroup\$ –  Arthur Ulfeldt Commented Sep 24, 2019 at 17:43

4 Answers 4

Obviously when you already have one in your hands, you can measure its true capacity.

However lets for a moment think about where these fake cells might come from:

• Cheap companies that have little expertise in bleeding edge battery technology
• Contracted factories that just leave the machines running for a while after they produce the parts for high end battery companies

In the first case you can be sure that the real capacity is on a much lower level.

In the second case the capacity is at most at the level of the best competitors on the market.

In conclusion: anything that is above the well established brand names is a blatant lie. Anything that is at their level might be a lie or could be true, no way to figure out than to measure it.

• 1 \$\begingroup\$ Is there a good site or resource that keeps track of the 18650 capacities as they climb? I.E. will be continually up to date? What I'm looking for is a source for (today's) realistic range of 18650 mAh capacities, kept up to date. \$\endgroup\$ –  Ehryk Commented Mar 1, 2016 at 10:21
• 1 \$\begingroup\$ @Ehryk: Not any that I would be aware of, just have a look at the big players datasheets \$\endgroup\$ –  PlasmaHH Commented Mar 1, 2016 at 10:28
• \$\begingroup\$ I've recently come across an 18650 database although I don't know how up to date it is. Here's the link: diypowerwalls.com/celldatabase.php \$\endgroup\$ –  Levi Roberts Commented Sep 3, 2017 at 18:00

If the cell is actually genuine (no guarantee about that ) then it should follow the datasheet. Note that genuine and unmodified 18650 cells are not generally sold through legitimate distributors such as Digikey or Avnet, probably for liability reasons.

Most of the ones you see with unknown brand names (anything with 'fire' in it, IME) will have a fraction to a small fraction of the claimed capacity. Maybe 1000mAh rather than 4000 or 6000 or whatever they are claiming this week. The crap ones will be significantly lighter than the genuine cells, and probably made with inferior materials internally. If you're lucky (and they claim protection) they'll have short-circuit protection polyswitches to reduce the chances of drama. Undervoltage protection is also possible, but less common.

Many of the folks selling these online on eBay, Aliexpress etc. are shady criminals to begin with in that they're lying about the contents of the package and dropping it in airmail. Extremely dangerous practice.

There are websites (probably flashlight related) that do some testing and you will have a better chance if you follow their recommendations. You can also find some cells with protective circuits added from distribution.

• \$\begingroup\$ I'm building a battery bank, with 4A polyfuses and my own external protection circuitry, so I'm just after the raw 18650 unprotected cells. It's just hard to tell at what point I'm better with 8x "9,800 mAh" (which might be really 1000 mAh) vs 1x genuine 3,500 mAh - note that I'm still potentially getting more capacity per dollar from the liars, depending on their actual rating. \$\endgroup\$ –  Ehryk Commented Mar 1, 2016 at 19:38

I bought some 9800 mAh Li ion 18650 batteries on eBay and tested them with my genuine SkyRc charger/tester. maximum capacities were between 990 and 1080 mAh each with a sample set of four cells. Yes I was hoping for 2500 mAh, but for two dollars you get what you pay for. Where weight or size is not an issue, you are correct; The liars offer cheap energy capacity at even 10% of the advertised capacity. All the usual caveats apply with purchasing substandard products so good luck. :)

• 1 \$\begingroup\$ Welcome to Electronics.SE but this doesn't seem to answer the original question. \$\endgroup\$ –  tangrs Commented Aug 1, 2017 at 6:46
• \$\begingroup\$ What is their C rating? \$\endgroup\$ –  neverMind9 Commented Jul 6, 2018 at 13:46
• \$\begingroup\$ They might try explaining it away by saying the listing lets you buy 1, 2, 3, 4, or 10 and the big number is when you buy 10 and use them in parallel. That said, the listings that boast 79,000mAh are still ridiculous. 🙄 \$\endgroup\$ –  Synetech Commented Apr 25, 2022 at 20:03

At least these are fireproof:

These... maybe not.

Source: fake 18650 teardowns .

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