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  1. Here are the links to each of my blog entries. This index will be updated as new entries are added.

    You are responsible for your own safety!

    These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic cigarette) use or for use without protection circuitry. Use of these batteries is AT YOUR OWN RISK!

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage.
    • Only buy batteries from a known, trusted vendor of genuine batteries.
    • Never use a battery, charger, or device that is not in perfect working order.
    • The plastic battery wrap and top insulating ring must always be kept in perfect condition to prevent short-circuiting of the battery which can result in the battery bursting.
    • Never exceed the battery's continuous discharge rating (CDR) or charge rating.
    • I am not responsible for any damage or injury sustained by anyone using this information to select a battery.
    Link to All My YouTube Videos
    Links to All My Tests and My Recommended Batteries
    Test Results, Ratings, and Performance Tables
    Assorted Battery Stuff
    Some Good Vendors
    www.akkuteile.de
    www.batterybro.com
    www.ecoluxshopdirect.co.uk
    www.illumn.com
    www.imrbatteries.com
    www.liionwholesale.com
    www.nkon.nl
    www.orbtronic.com
    www.rtdvapor.com
    Lee1234, JoAnnW, AlaskaVaper and 20 others like this.
  2. They are meant only to give you an idea of the risk if a battery is accidentally discharged at beyond its continuous current rating when vaping. You should not consider them as a rating for the battery that you can vape at!

    If properly used the MVA limit can help increase our safety. But it has been misused by too many.

    Safety is important and must guide us in the recommendations we make. I have decided to remove the MVA limit numbers from my tables and ask that everyone delete any tables they have now and download the new ones that are available. See the links below.

    Please do not post or distribute any earlier version of these tables.
    Please delete any earlier version of these tables you might have posted.
    Please do not recommend the MVA limit as an acceptable vaping level.

    I ask this with all the sincerity and urgency that I can muster...please.

    Our community is under increased scrutiny and battery and vaping hardware (atomizer and device) regulations/standards are now being discussed and written...very severe ones. I am not allowed to discuss some of what I've learned but it could be bad. We must set a good example and self-regulate our community as best as we can. I cannot emphasize too strongly the importance of this.

    I realize that many are vaping at discharge levels considerably above the continuous discharge rating (CDR) of their batteries and have done so without incident. But that doesn't mean it's done without risk.

    Giving the community the tools and data we need to pick the best battery is very important to me though. I have a way to replace the pulse testing I do now. These new tests can be used to directly compare how hard one battery hits versus another and which is the better performer. It will simplify my testing too.

    Many battery wrapping companies sell batteries with ratings that are considerably higher than the battery's true ratings. This is an issue I will continue to devote a lot of my time to.

    I realize that many of you will be upset at these changes. I'm not doing this to piss off the high power vapers. :) You will still have the tools you need to pick the best performing battery. I will post about this soon.

    But I can only recommend to our community that we never exceed the continuous current rating (CDR) of any battery. These batteries were never meant to be used outside of a battery pack with suitable protection electronics.

    Each of us can decide the level of risk we wish to take ourselves but we should recommend safe battery use to others.

    Thank you for your time.
    Sorry for the long read and the inconvenience of having to replace your tables!

    18350/18500 table:
    18350/18500 Safety Grades and Pulse Performance Data | E-Cigarette Forum

    18650 table:
    18650 Battery Ratings -- Picking a Safe Battery to Vape With | E-Cigarette Forum

    20650/20700/21700 table:
    20650/20700/21700 Battery Safety Ratings Table | E-Cigarette Forum

    26650 table:
    https://www.e-cigarette-forum.com/blog-entry/26650-safety-grades-and-pulse-performance-data.7554/
    Richard-D, gt_1955, suprtrkr and 3 others like this.
  3. You are responsible for your own safety!

    These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic cigarette) use or for use without protection circuitry. Use of these batteries is AT YOUR OWN RISK!

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage.

    • Only buy batteries from a known, trusted vendor of genuine batteries.
    • Never use a battery, charger, or device that is not in perfect working order.
    • The plastic battery wrap and top insulating ring must always be kept in perfect condition to prevent short-circuiting of the battery which can result in the battery bursting.
    • Never exceed the battery's continuous discharge rating (CDR) or charge rating.
    I am not responsible for any damage or injury sustained by anyone using this table to select a battery.

    The table below only notes the ratings for batteries at the time I tested them. For any battery not in a Samsung, Sony, LG, Panasonic, or Sanyo plastic wrap the battery being used can change at any time! This is one of the hazards of using “rewrapped” batteries. To avoid this issue only use genuine Samsung, Sony, LG, Panasonic, or Sanyo batteries in their original plastic wraps.


    Here are the ratings for the 20mm and 21mm diameter batteries:

    907E0B08-8EC2-4043-A892-48B25FD1533A.jpeg

    Click the above thumbnail to open the full size table.

  4. You are responsible for your own safety!

    These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic cigarette) use or for use without protection circuitry. Use of these batteries is AT YOUR OWN RISK!

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage.

    • Only buy batteries from a known, trusted vendor of genuine batteries.
    • Never use a battery, charger, or device that is not in perfect working order.
    • The plastic battery wrap and top insulating ring must always be kept in perfect condition to prevent short-circuiting of the battery which can result in the battery bursting.
    • Never exceed the battery's continuous discharge rating (CDR) or charge rating.
    I am not responsible for any damage or injury sustained by anyone using this table to select a battery.

    807B061C-D301-4DB0-8871-B5A78277BF74.jpeg

    Click on the thumbnail above to open the full-size table
  5. It's widely believed that the LiPo battery packs used in DNA200/250 and custom box mods need to be charged/discharged several times before they reach their peak performance.

    Is this true?

    To find out I took three new 3S packs and balanced charged them at 5A on an iCharger106B+ to 12.60V followed by a discharge to 9.0V at 20A constant-current. I did this a total of five times for each pack with a 60 second rest between each step. A lot of effort was made to ensure that the pack temperatures were consistent from cycle to cycle.

    Here are the three discharge graphs:
    IMG_4846.jpg IMG_4847.jpg IMG_4848.jpg

    As you can see there was no increase in the capacity of the pack or an increase in its voltage while being discharged (which would indicate a decrease in its internal resistance).

    For two of the three packs I measured the internal resistance before and after the tests were done:

    Turnigy 25C-35C 2200mAh before = 18.3 mOhms
    Turnigy 25C-35C 2200mAh after = 18.5 mOhms

    MaxAmps 100C 2250mAh before = 21.9 mOhms
    MaxAmps 100C 2250mAh after = 22.8 mOhms

    The break-in cycles didn't lower the internal resistance of the packs. In fact, they did exactly what any use of the pack does...ages the pack and increases its internal resistance.

    The break-in cycling did not improve the performance of any of the three packs. It only wasted five of the limited number of cycles available before the packs would need to be replaced.

    I also did five break-in cycles for each of the ten 1800mAh 3S LiPo packs I recently tested. Those break in cycles were done at some pack assembler's typical recommended levels, 1C charge and 2C-3C discharge. There was no increase in performance between cycle 1 and cycle 5 for any of the packs.

    Will this be the case for every LiPo? I don't know.

    There might be some LiPo's that were not fully formed (initialized) at the factory in order to save money. Their performance would increase during the first few cycles. There also might be some that were stored for a long time before being used. This can cause the thickening of an important chemical divider (the SEI layer) between certain parts of the battery, increasing its internal resistance. Cycling the battery can reduce its thickness and restore some performance.

    I know that many in the R/C community feel strongly that this cycling is needed but the tests described above and my recent testing of ten different 1800mAh 3S LiPo packs showed no increase in performance after being cycled a few times.

    I have an idea why some might feel they are seeing an improvement in performance though.

    LiPo cells, which use lithium-cobalt chemistry, show a very small change in voltage for a big change in capacity during most of the discharge compared to other Li-Ion chemistries. This "flat discharge curve" is one of the big benefits of using LiPo's.

    But this flat discharge curve also means that just a small change in the voltage of the battery can result in a big change in the capacity the battery delivers to cutoff voltages above 3.2V or so. If the pack is warm its internal resistance drops and the voltage the pack runs at is higher. This allows the pack to run for a lot longer before dropping to the cutoff voltage.

    Since the outer wraps of a LiPo pack are very effective heat insulators the internal temperature of a LiPo pack can be a lot higher than the external temperature. It can seem to be only a bit above room temperature but actually be much warmer. Unless the pack is allowed to sit for at least an hour after charging, two hours or longer for larger packs, the internal resistance could be lower than when the pack was first used in the tests.

    This would cause the packs to run at a higher voltage, making it seem that its performance had improved with cycling. But the improved performance was really only due to the pack being warm.

    I am not saying that everyone who cycles their packs and says they see an improvement is wrong!

    I am not saying that no LiPo packs respond to break-in cycling!

    I am merely saying that in my testing of thirteen different packs I see no sign of break-in cycling having any effect on performance. It shouldn't though. Properly formed packs, not stored for months and months, should not need any sort of break-in to reach their best performance levels.

    I'd be interested in hearing your experiences regarding breaking in LiPo packs, especially if you took measures to make sure internal pack temperatures were consistent for each cycle.

    Thanks!
  6. You are responsible for your own safety!

    These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic cigarette) use or for use without protection circuitry. Use of these batteries is AT YOUR OWN RISK!

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage.
    • Only buy batteries from a known, trusted vendor of genuine batteries.
    • Never use a battery, charger, or device that is not in perfect working order.
    • The plastic battery wrap and top insulating ring must always be kept in perfect condition to prevent short-circuiting of the battery which can result in the battery bursting.
    • Never exceed the battery's continuous discharge rating (CDR) or charge rating.
    • I am not responsible for any damage or injury sustained by anyone using this information to select a battery.

      Here are the ratings I am using for LiPo's...

      CDR = Continuous Discharge Rating. The nearest 5A-multiple of constant-current continuous discharge current that brings the inner cell of a 3S pack to a temperature of 60°C. This is what the LiPo assemblers recommend as the max running temperature so it makes sense to use it as the rating. Especially since the inner cell will be hotter internally than this temperature, perhaps considerably.

      Testing shows that the temperature of the middle cell in a 3S pack is 7°C-10°C higher than the temperature of the outer cells (but still under the shrink wrap and protection wrap). This means that when I measure a temperature of about 50°C-53°C the inner cell of a pack has reached at least 60°C, its limit. A 2S pack will run a bit cooler and a 4S, or higher, pack will run a bit hotter than this.

      Most of the 3S packs I have start puffing (temporarily) at around 60°C or lower so I agree with the pack assemblers that it should be used as the max running temperature for decent cycle life. Going over this temperature will start damaging the pack a lot faster. Note that at an internal temperature of 60°C the outside of a pack is just warm.

      The protective and shrink wraps used on these packs are very effective insulators. It takes at least an hour for each pack to cool back down to room temperature internally. These 1800mAh packs are small too. Larger packs would take at least a couple of hours to cool.


      BEING UPDATED

      Click on the thumbnail above to download the 1800mAh 3S LiPo pack ratings table
  7. It's time to put this myth to rest. Using rice to help dry batteries or a mod that got wet doesn't help at all. In fact, it slows down evaporation of any water that is inside.

    I set up a 24 hour test using paper towel sheets with enough water added to bring their weight to 18 gms. I then put these wet folded paper towels in four places; a slightly ventilated box in rice, a slightly ventilated box 3 feet in front of a fan on low, a bare folded paper towel in still air, and a bare folded paper towel 3 feet in front of a fan on low. The complete results are in the table but two are presented here...
    • Amount of water that evaporated from the box in the rice after 24 hours = 2 gms
    • Amount of water that evaporated from the box in front of the fan after 24 hours = 10 gms
    Five times more water evaporated from the box that was in front of the fan. It's clear that burying anything in rice just slows down the evaporation of any water that's present. This makes sense though. Rice can't vacuum up water. It can only absorb any water that evaporates and touches the surface of the rice. Even then though rice is a lousy absorber of atmospheric water.

    Since the device that is wet is buried in rice, with no air movement, the humidity level quicky rises up to 100% next to any water that is present inside the device. This significantly slows down any evaporation that could take place.

    Adding air movement blows away the layer of very humid air above any water, allowing the water to evaporate much faster.

    Some of you might have tried using rice and found that you could turn on your mod a day or two later and it worked. But did you open up your mod to see if the water had actually evaporated? How can we know that the rice did anything?

    Bottom Line: If you have a mod that got wet, do not turn it on. Remove the batteries (if possible), shake out any water you can, and then place it in front of a fan. Rotate it every couple of hours to try to get any blowing air into any seams or ventilation holes. It should be pretty dry internally in 24 hours.

    Please don't bury it in rice!

    [edit] I'm sure there will be those who feel this test was invalid for one reason or another. It's backed up by every good test like this I found online but I strongly encourage anyone who feels I erred to do their own tests. I would love to see the results!

    [edit] For those who are concerned that the paper towels "lock in" the water, keeping it from evaporating:

    Pictures of the setups:

    Attached Files:

    Baditude, untar, KS_Referee and 6 others like this.
  8. Some chargers, like the Efest LUC V4, can be used to charge batteries that have dropped to very low voltages, below 2.5V. While this is tempting there is a risk when doing this.

    When a Li-Ion battery drops below 2.0V or so the copper electrode inside of it literally starts to dissolve. When the battery is recharged this dissolved metal is plated back onto parts of the battery that should not be conductive. This can cause an internal short-circuit which can lead to overheating, venting, or even bursting of the battery. Even if it still works after charging that battery might be damaged and wouldn't be married to the other batteries you used with it anymore.

    It's impossible to say though whether any over-discharging of a battery is unsafe or not since the battery damage is cumulative. The more time it spends at around 2.0V, and the lower the voltage, the more damage is done and the riskier it is to use that battery. If the battery is recharged quickly then the damage is minimal. If the battery slowly self-discharged over months of storage then the damage is greater and the risk is a lot higher.

    I'll always recommend just replacing an over-discharged battery if you weren't able to recharge it right away. If you do decide to use it though I recommend the following...

    - Recharge it as soon as possible.

    - Recharge it at the lowest current setting possible.

    - Stay nearby! You want to be able to stop the discharge immediately if the battery starts overheating or there is some other problem.

    So while the recovery feature can help bring back a battery that was overdischarged you need to weigh the risks versus replacing the battery. Remember, even if you recover the battery it might be damaged and no longer married to its partner(s). Keep an eye on the battery voltages and temperatures for a while to make sure the recovery went well.
  9. PBusardo was kind enough to offer me a page on his web site and I jumped at the chance. The first article is up. Thank you for this opportunity Phil!

    http://www.tasteyourjuice.com/wordpress/the-battery-mooch
  10. Even though the Sony VTC4 is still in production and genuine ones are available there are vapers who are uncomfortable taking a chance at buying counterfeit Sony batteries. Could the 22A-25A rated LG HD2, HD2C, and HD4 be as good as the Sony VTC4? Let's find out.

    In the graphs below I discharged all four batteries at 10A-20A-30A continuous and 30A pulsed. In the constant current graph all of them ran at about the same voltage at 10A continuous but the HD2C lasted a bit longer. At 20A and 30A continuous the HD2C ran at a higher voltage (hit harder) than the others and still lasted longer. The VTC4 didn't beat the HD2C but it performed a bit better than the HD2 and HD4.

    In the 30A pulse current graph the HD2C lasted a bit longer than the rest with the VTC4 and HD4 about tied for second place. While the HD2C ran at a slightly higher voltage than the others when pulsed they were all very close in performance and I don't think you'd see a difference in actual use.

    So, is there a good alternative to the VTC4?

    Yes, the LG HD2C.
    It not only runs at a slightly higher voltage but lasts a bit longer too. The LG HD4 is a close second in these tests and is roughly equivalent to the VTC4 for vaping at up to about 25A-30A/100W.

    image.png image.png image.png
  11. Those are lithium-ferrous-phosphate batteries, or "LFP". They are also called IFR. They are a different type of Li-Ion chemistry than the ones we use most often when vaping, often called IMR, INR, and ICR.

    The continuous discharge current specifications for these batteries seem to be perfect for vaping; 30A for the 18650 and 70A for the 26650. But there are a few things to consider before using them in a mod...
    • The A123 18650 is only 1100mAh. The A123 26650 is only 2300mAh.
    • LFP batteries have a lower nominal voltage than the IMR/INR/ICR batteries we normally use, 3.3V. While you can compensate for this lower voltage in an unregulated/mechanical mod it means that regulated mods will stop firing and show a weak/low battery message much sooner than normal.
    • LFP batteries need a 3.6V charger. They cannot be charged to 4.2V!
    There is one very important advantage to these LFP batteries though: they are the safest Li-Ion chemistry we can use. The temperature at which they go into thermal runaway is higher than IMR, INR, or ICR batteries. If they do go into thermal runaway the reaction is much less violent than with other chemistries. There are usually no flames and the temperature of the reaction is much lower.

    Does this increased safety, and the high current ratings, make LFP batteries worth using in our mods? In my opinion, no. Being limited to unregulated/mech mod use, modifying the build resistances, and buying another charger is a lot to do just to use a low capacity battery. Even if it is safer when short-circuited.

    The A123 26650 battery might be worth the trouble and low capacity since it has a current rating far above any other 26650. But is it that much better than two 30A IMR or INR 18650's? Not really. Is it safer? Yes, a bit. But if you don't abuse your 18650's and maintain their wraps the extra safety is never needed.

    So, can we use LiFePO4 batteries for vaping? Yes.
    I don't feel they're worth the compromises though. But if safety is your top priority perhaps they might be worth it for you.

    image.jpeg image.jpeg
  12. It's tempting to use very high capacity batteries, over 3000mAh, to try to get more vaping time before needing to recharge. But there aren't any 18650 batteries with a capacity over 3000mAh that have a rating above 10A!

    Batteries like the Panasonic 3200mAh NCR18650B look like a great way to get more vaping time but they're only rated at 4.9A. And the Efest, Imren, and other Chinese-company high-capacity batteries are just rewraps of 10A Panasonic and LG batteries.

    If you vape at under 20W (per battery) or so then you can use the 3200mAh Panasonic NCR18650B.

    If you vape at under 35W (per battery) or so then you can use the over-3000mAh Efest's, Imren's, etc. But Panasonic/Sanyo NCR18650GA, LG MJ1, and LG MH1 batteries are less expensive and possibly a higher grade.

    Can you vape at higher power levels with these 4.9A and 10A batteries? Of course! The batteries won't explode and your face won't melt off if you do.

    But the voltage sag is so severe that at over about 5A-7A you can actually get more vaping time from the 3000mAh LG HG2 and Samsung 30Q. This is because their internal resistance is lower than the over-3000mAh batteries. This allows them to run more efficiently, with less voltage sag, and that means they run for longer before your mod says low/weak battery.

    So, know your batteries and vape safe.
  13. If you want to start going beyond what www.batteryuniversity.com covers here are a few of the more interesting papers I've read on Li-Ion batteries. They are quite technical though!

    Thermal runaway caused fire and explosion of lithium ion battery:
    https://www.researchgate.net/profile/Qingsong_Wang4/publication/257224404_ChemInform_Abstract_Thermal_Runaway_Caused_Fire_and_Explosion_of_Lithium_Ion_Battery/links/54cf7bc10cf29ca810fe2f30.pdf?origin=publication_detail

    Thermal runaway in Li-Ion — getting the missing data:
    http://www.helgroup.com/articles/pdf/b426f8c49b436d84/Thermal Runaway in Li-ion Article Best Tech Magazine.pdf

    Theory of SEI Formation in Rechargeable Batteries:
    http://arxiv.org/pdf/1210.3672v3.pdf

    Advanced Technology Development Program for Lithium-Ion Batteries, Thermal Abuse Performance of 18650 Li-Ion Cells:
    http://prod.sandia.gov/techlib/access-control.cgi/2004/040584.pdf

    Are Lithium Ion Cells Intrinsically Safe?:
    http://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/alici_v2.pdf

    Understanding Lithium-Ion Technology:
    http://www.battcon.com/papersfinal2008/mcdowallpaper2008proof_9.pdf

    Mechanism of intercalation and deintercalation of lithium ions in graphene nanosheets:
    Mechanism of intercalation and deintercalation of lithium ions in graphene nanosheets | SpringerLink

    In-operando high-speed tomography of lithium-ion batteries during thermal runaway:
    http://www.nature.com/ncomms/2015/150428/ncomms7924/pdf/ncomms7924.pdf

    Some thermal runaway and Li-Ion abuse papers:
    https://www2.unece.org/wiki/download/attachments/24477990/EVS-06-35e.pdf?api=v2

    https://www.electrochem.org/dl/interface/sum/sum12/sum12_p057_060.pdf

    http://www.nrel.gov/transportation/energystorage/pdfs/43186.pdf

    http://www.helgroup.com/articles/pdf/b426f8c49b436d84/Thermal Runaway in Li-ion Article Best Tech Magazine.pdf

    http://jes.ecsdl.org/content/162/9/A1905.full.pdf

    http://www.battcon.com/PapersFinal2015/17 Ponchaut Paper 2015.pdf

    https://www2.unece.org/wiki/download/attachments/24477990/EVS-06-35e.pdf?api=v2

    http://pubs.rsc.org/en/content/articlepdf/2014/RA/C3RA45748F

    Aging Mechanisms in Li-ion Batteries:
    https://www.mecheng.osu.edu/nlbb/files/nlbb/Battery_aging_09.pdf

    Degradation Mechanisms and Lifetime Prediction for Lithium- Ion Batteries – A Control Perspective:
    http://www.nrel.gov/docs/fy15osti/64171.pdf

  14. You are responsible for your own safety!

    These batteries are designed, manufactured, and sold only for use in a battery pack with the proper protection circuitry and battery management system. They were not designed for vaping (electronic cigarette) use or for use without protection circuitry. Use of these batteries is AT YOUR OWN RISK!

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage.



      • Only buy batteries from a known, trusted vendor of genuine batteries.
      • Never use a battery, charger, or device that is not in perfect working order.
      • The plastic battery wrap and top insulating ring must always be kept in perfect condition to prevent short-circuiting of the battery which can result in the battery bursting.
      • Never exceed the battery's continuous discharge rating (CDR) or charge rating.
      • I am not responsible for any damage or injury sustained by anyone using this information to select a battery.
    I'm often asked what batteries I would recommend. Here's the entire list. :)

    It does not mean I think your batteries are bad if you use ones not on this list!
    These are merely my personal recommendations to help reduce the number of different batteries to choose from.

    Note: The non-Samsung/Sony/LG/Panasonic/Sanyo batteries can change what is used under the wrap at any time.

    7FDF0DBF-4D99-4676-932D-B3259735EF7D.jpeg

    Click on the thumbnail above to download the table
  15. There are several things you can do to help your Li-Ion batteries last as long as possible before needing to replace them. Some are easy, some are quite inconvenient. Some have a big effect, some very little. But doing any of them can help slow down the aging and degradation of your batteries.

    Temperature
    • Don't overheat them. High temperatures are the biggest cause of battery damage and reduced battery life. Anything over about 45°C/113°F, what most would call warm, and your batteries start aging faster. The more time they spend being warm or hot, and the hotter they get, the more damage you're causing.
    • Don't use them when they're very cold, below -20°C/-4°F. The chemical reactions in a battery are a lot less efficient at low temperatures leading to poor performance. The sudden heating of the battery if used when cold can cause localized internal heating, possibly damaging the battery.

    Discharging
    • After using your battery, let it cool to room temperature before charging it.
    • Don't overdischarge them. Our batteries are rated down to 2.5V or lower but you can extend their life by staying above 2.8V-3.0V***. Going below 2.0V or so leads to metal being plated inside different parts of the battery, eventually causing an internal short circuit and possible bursting of the battery.
    • If you accidentally overdischarge your battery below 2.0V immediately recharge it at the slowest rate your charger supports. Once the battery rises up over 3.0V or so you can switch to your normal charge rate.
    • If battery has been at 2.0V for a while then it's probably damaged. It's not worth trying to use the "recovery" mode of your charger (if it has it) because the damage can lead to an internal short circuit later.
    • Li-Ion batteries do not need to be discharged occasionally all the way down in order to keep them in top condition. Li-Ion batteries do not suffer from "memory". This is only needed for NiCd (nickel-cadmium) or NiMH (nickel metal hydride) batteries.
    • Partial discharging and recharging multiple times is better for long battery life than discharging all the way down to where the mod indicates "low battery" and then recharging.

    Charging
    • After charging, let your battery cool to room temperature before using it.
    • Don't charge a battery that is below 0°C/32°F. It causes metal to be plated inside the battery eventually leading to an internal short circuit and possibly bursting of the battery.
    • Where possible, setting your charger to 4.1V will reduce stress on the battery and extend its life. But you will lose 10%-15% of the capacity of the battery.
    • Make sure the charger you use turns off once the charge is complete. Check the instructions for the charger you want to use.
    • Never use a trickle charger with Li-Ion batteries! The continuous holding of the battery at the trickle charge voltage damages it.
    • Don't overcharge them. To get the longest running possible time from a battery some chargers go up to as high as 4.27V. While this does result in a bit more vaping time before needing to recharge, it damages the battery. Most of the batteries we use are rated at up to 4.25V but even this is quite high. It's not dangerous until we're approaching 5V but battery damage starts occurring way below this.
    • Without a separate meter monitoring the battery's highest voltage before the charger stops it's hard to know what our batteries are actually being charged to. Our best option is to have our batteries spend as little time as possible fully charged and charge them just before using them. This usually isn't very convenient but it does extend battery life.
    • Charging at a slower rate is better, to a point. Most of our 18650 batteries have a "standard" charge rate of 1.0A-1.5A and a "rapid" charge rate of up to 4A. Charging at 0.5A might help extend the life of your batteries a bit but if the batteries are not getting warm at 1.0A then that's a good compromise between battery life and convenience. Going down to 0.375A or 0.25A won't help much versus charging at 0.5A.
    • Charge 18350's at 0.5A until you know that they aren't getting more than a bit warm.
    • Charge 26650's at 1.0A until you know that they aren't getting more than a bit warm. The better 26650's can be charged at up 2.0A without adversely affecting battery life.

    Miscellaneous
    • Storing batteries in the refrigerator doesn't make much of a difference in battery life unless you live in an area with high temperatures year around. It's not dangerous to refrigerate them but be sure to let them come to room temperature before opening whatever airtight wrapping/container you have them in.
    • If a battery wrap becomes damaged, replace it immediately. Replace the top insulator ring if it's also damaged.
    • Every time you buy batteries also buy battery boxes or sleeves, wraps, and top insulator rings. You...will...need...them.

    Additional Information

    ***This is the resting voltage, NOT the voltage "under load" that the battery drops to when being used. If your mod stops firing when the battery drops to 3.2V the battery can rise back to to 3.5V or even higher after resting for a while. This "resting voltage" is the important voltage, the one to be used when determining how low you are really discharging your batteries.

    While stopping at 3.4V, 3.6V, or even higher might extend battery life a bit you are missing out on a lot of additional vaping time that you could use before needing to recharge. That additional vaping time can be enjoyed every day for, at most, just the cost of one extra set of batteries a year. Stopping at these higher voltages won't hurt the battery though. Just let the batteries sit for an hour before charging to see what their true resting voltage is when deciding how low you want their voltage to go in your mod.