(9) Battery Basics for Mods; the Ultimate Battery Guide
As mod users, we depend heavily upon batteries. To assist novices to choose which external (removeable) battery to use in their mod I have written this guide. Our choices in batteries are Lithium Ion batteries, the same "chemistry" often used in cell phones, laptops, cordless power tools, high end flashlights, and remote control cars. However, there are multiple classes of Lithium batteries and only one class is really best suitable for vaping:
- Lithium IMR or Li-Mn
- IMR/Hybrid batteries (new sub-class of IMR, and the most common/recommended battery)
- protected ICR Li-Ion*LiPo batteries used as the internal batteries in the eGo, MVP, iStick, etc will not be discussed here other than to say they are not safe chemistry, and depend upon the protection circuitry of these mods which utilize a non-replaceable battery.
High quality IMRs are currently recommended in place of protected ICR Li-Ion for all vaping applications. Protected ICR batteries are considered to be obsolete for our purposes.
IMR (Li-Mn) are the safest batteries available for vaping. By adding nickel or manganese to carbon-based lithium batteries they become a safer chemistry and don't require the built-in protective circuit like ICRs require. They have higher tolerence to stress and heat buildup, and although they may vent hot gas during failure, they are less likely to be as dramatic as an ICR or LiPo battery venting. Should protective circuits fail in ICRs they can vent violently in flames and possibly explode.
An Ultrafire protected ICR battery in thermal runaway
A LiPo battery in thermal runaway
Guide to Battery Specification Terms: Batteries can generally be broken down by two major characteristics: capacity (mah rating) and amps (current handling). When choosing which battery to buy you must pick which characteristic is your priority for the application that you will use it. You can't have both the highest mah and highest amps in one battery. This is due to the limits of current battery chemistry & technology. Safety should always be your number one priority.
Capacity or mAh Rating - an approximation for how long a battery charge should last from 100% charge to when the battery will cut off. Roughly, 100 mAh = 1 hour usage with low drain applications like a flashlight.
The "best battery" is not always the one with the largest mAh rating. In most vaping applications a higher amp rating (CDR or continuous discharge rate) determines the better battery.
Amp Rating - or "continuous discharge rate" (CDR), is the maximum electrical current at which the battery can be discharged continuously before the battery will fail. This specification is set by the manufacturer, and is a standard measurement in the industry. The "pulse or burst discharge rate" is not a standard measurement and varies from one manufacturer/vendor to another making comparisons from company to company impossible, and therefore should never be relied upon.
Beware of dubious marketing claims of over-rated battery amp ratings and mAh ratings by some disreputable vendors and manufacturers. These companies attempt to confuse consumers with "max amps" specs. Efest, IMREN, and the "---- Fire" brands are the worst perpetrators of this practice.
Look for the continuous discharge rate (CDR). Burst or pulse ratings are just that, they can do a high amperage for 2-5 seconds, but more than that you begin to damage the cells. You want to run batteries at their continuous rate, never for their burst. This is the danger of sub-ohming and not knowing the ins and outs of your batteries.
Purple Efest Batteries Not As Advertised
Imren Purple 40a 2500mah 18650 bench test results; only a 20a battery, runs very hot
Battery pulse ratings are useless! | E-Cigarette Forum
Technical discussion of a Purple Efest battery venting incident in a regulated mod
High Quality, Brand Name Batteries. Not all ICR and IMR cells are created equal. This is where the supplier/manufacturer comes into play. There are quite a few different makers, some you can trust some you can’t. I will give a quick rundown of them and what makes them better. I recommend buying only the batteries from the list below, paying attention to model numbers and their specifications. (CDR is the continuous discharge rating in amps.)
18650 2000mah 10Amp CDR
18650 1600mah 24Amp CDR
18490 1100mah 16.5Amp CDR
18350 700mah 6Amp CDR
18650 3000mah 20Amp CDR (new IMR/hybrid)
18650 2200mah 20Amp CDR (new IMR/hybrid)
18490 1200mah 18A (new IMR/hybrid)
18350 800 mah 12A (new IMR/hybrid)
18650HE2 2500 mah 20Amp CDR
18650HE4 2500mah 20Amp CDR
18650HG2 3000mah 20Amp CDR
18650HB6 1500mah 30A CDR
18650 1500mah 20Amp CDR
26650 3800mah 20A CDR
Panasonic or Orbtronic (IMR/Hybrid)
CGR18650CH 2250mAh 10A CDR
NCR18650BD 3200mAh 10A CDR
NCR18650PF (LiNiCOMnO2) 2900mAh 10A CDR
NCR18650PD (LiNiCoAl) 2900mAh 10A CDR
Orbtronic 18650 3500mAh 10A CDR
Orbtronic 18650 SX22 2000mAh 22A CDR
Orbtronic 18650 2500mAh 21A CDR
Orbtronic 18650 SX30 2100mAh 30A (*tested as only a 20 amp CDR)
Panasonic 26650 CGR2650A 2650mAh 50A CDR
Orbtronic 26650 5200mah 20A CDR
* Note that the Panasonic/Orbtronic 18650A (3200 mah) and 18650B (3400 mah)
have less than 7 amp CDR and are not recommended for use in today's modern APV's.
These were designed to be used for only low drain applications like flashlights.
Samsung (IMR/hybrid) (LiNiCoMnP)
INR18650-30Q 3000mah 15A CDR
INR18650-20R 2000mah 22A CDR
INR18650-25R 2500mAh 20A CDR
18650VTC4 2100mAh 30A CDR
18650VTC5 2600mAh 30A (* tested as only a 20 amp CDR)
26650 2600mAh 26A CDR
18650 2250mAh 10A CDR
18650 2000mAh 10A CDR
18650 1600mAh 30A CDR
18490 1100mah 8.8A CDR
18350 800mah 6.4A CDR
purple 18650 2800mAh "38A" (* tested as only a 20 amp CDR)
purple 18650 2500mAh "35A" (*rebranded LG18650HE2 2500mAh 20 amp CDR)
purple 18650 2100mAh 30A (* tested as only a 20 amp CDR)
purple 18650 2100 mah "38 Amp" (* tested as only a 20 amp CDR)
purple 18500 1000mAh 15A CDR
purple 18350 700mAh 10.5A CDR
Efest 26650 4200mAh 20A CDROur ECF buddy and battery expert @Mooch has been doing some independent battery testing. Before you purchase a particular battery, look for the results of that battery in the below link:
- Lower Quality Brand-Name Batteries. Trustfire, Ultrafire, and Surefire are a lower-tier name brand battery in terms of quality and safety. Not recommended. The same goes for AWT, Basen, Cloud Chaser, Imren, MXJO, and Vappower brands. Independent tests have revealed that they have over-rated specifications from what is advertised.
- Generic Batteries. Not recommended. No name or off brand printed on the wrapper. Seen at FastTech, Amazon & EBay at cheap prices or thrown in for free in a kit when you purchase a mod from China. These are unknown batteries of unknown quality by an unknown manufacturer, and not worth the risk using in your mod. Never assume because they were included with your mod that they are safe or the correct battery to use.
- Be cautious when shopping for batteries. Unprotected ICR batteries should NEVER be used in a mod. Be aware of fake AW & Sony batteries.
How to identify older counterfeit AW batteries
How to identify counterfeit Samsung25R batteries
How to identify counterfeit Sony batteries | E-Cigarette Forum
Final word on Sony's production plans for the US18650 VTC4 and the US18650 VTC5 (April 9, 2015) (Sony is still producing these only for OEC power tools, and does not approve of their sale on the open market for other applications. These are still often available to vapers, but should only be purchased from the below trusted vendors to avoid getting counterfeits.)
- If uncertain about the quality or type of a battery, don't buy or use it. Do not use over-the-counter alkaline batteries (wrong chemistry) like those from Radio Shack, etc. To insure getting authentic name brand IMR batteries, buy only from trusted e-cig/flashlight vendors such as:
- Use the type of battery that your mod calls for. For example, Provape recommends using only AW IMR button top batteries in the Provari; using magnets on flat top batteries will void their warranty because this is an unsafe battery practice.
- Battery Chargers. Get the best charger that you can reasonably afford, again from a reputable e-cig vendor. Statistically most battery incidents occur while batteries are charging. A higher end charger will have better built-in protections.Pila, Xtar, Nitecore, and Efest are the most recommended brands. Recommend batteries be charged on a flame-resistant surface: stove top, marble countertop, metal baking pan, pyrex glass dish. Do not charge batteries if you are not physically present to keep an eye on them.
Many of today's higher-end box chargers have "intelligent" technology designed for the charger to shut down when the battery reaches full voltage (4.2 volts), however electronics can and do fail. Don't trust the safety of your home & family to a faulty electronic circuit or charging cord.
Rest batteries after charging
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.
Because of this, we think it may be a good idea to rest batteries after charging them. This advice will not be found in the usual 'reference bibles' on batteries, but we see more and different reports than others. Therefore we now advise:
Do not use batteries directly after charging them. Use a battery or batteries you previously charged, and that have rested for several hours. This is especially important if using a stacked pair for higher voltage, as statistically the risk is far higher.
- Always use safe battery practices and common sense with all batteries. Even the safest battery available to us can fail. IMR battery failure Most common user-error battery failures are the result of too fast of a discharge -- from the fire button inadvertantly pushed for too long, or the battery being shorted from metal objects (keys, change, etc), completing the electric circuit when carrying a battery in a pocket or purse. Use plastic Battery Cases. Do not stack batteries unless your mod was actually designed to use stacked batteries.
- Long term storage of unused batteries should be done in a dry place at room temperature (69 degrees F) at 40% voltage. Dispose of old unused batteries at a recycling center such as Radio Shack or Hope Depot.
- If you are using sub-ohm coils in an RBA/RDA, it is extremely important to use the highest quality IMR/hybrid battery with an appropriate amp rating. Coils less than 0.8 ohm require an IMR battery that has a maximum continuous discharge rate of at least 20 amps, preferably with a 30 amps continuous discharge rate.
PROTECTED ICR or IMR BATTERY: WHICH LITHIUM BATTERY IS BEST FOR YOUR APPLICATION?
IMR Li-Mn. Lithium manganese batteries. Also called "high drain", "safe chemistry", "unprotected".
- These are used in regulated mods that use buck boost circuitry to achieve variable voltage-wattage, but they are now also recommended for single voltage mechanical mods as a safer alternative to protected Li-Ion batteries.
- This class will have less capacity in mAh rating compared to protected ICR batteries, but are superior when maximum load current is required, such as in regulated mods, mechanical mods using a Kick, or using an RBA. Why High Drain Batteries?
- IMR cells have a lower internal resistance, which translates to a much more dynamic voltage curve in comparison to ICR. These will stay above 3.8v under load for a higher majority of their charge cycle, and then drop rather quickly afterward. This gives them a higher useable mAh*6 than their ICR brethren.
- New mixed chemistry batteries that are both safe chemistry/high drain and extended capacity in one. A good choice for applications that demand both maximum load current and longer battery time. Can be used for both mechanical and regulated mods. Most in this sub-class have 20 or more amps continuous discharge rate, ideal for sub-ohm mechanicals or high wattage regulated mods.
Protected ICR Li Ion. Lithium ion class batteries, also called "protected batteries".
- ICR batteries are now considered obsolete for mod use because of their potential for flames & explosion and their unacceptably low CDR.
CHOOSING THE RIGHT BATTERY FOR YOUR APPLICATION. HOW DO YOU VAPE?
For more in-depth information on mod batteries, see:The recommendations in the above pic from Pagasus Battery Revolution are too liberal in my opinion concerning amp limit specifications. I recommend a much higher margin of safety for sub-ohm vapers.
- If you use standard resistance coils (1-3 ohms) in a mechanical or regulated mod, then you should choose an IMR battery with more mAh capacity as your first priority. You won't need more than 10 amps CDR using this resistance, but you should still have at minimum 10 amps. Generally speaking, comparing two batteries with the same CDR but different mah ratings, the battery with more mAh (capacity) will last longer per charge than one which has less mAh.The Panasonic or Orbtonic 18650PF 2900mAh 10 amp CDR battery would be a great choice.
- If you use sub-ohm resistance coils (0.2 - 0.8 ohms) on a mech mod or high wattage regulated mod, your first priority must be for a high amp IMR battery of 20 - 30 amps CDR (maximum continuous discharge rate). Coils under the resistance of 1.0 ohm require more amp power due to their higher amp draw. Use the appropriate battery with an adequate amp rating depending upon the current draw of your coil build (*see the chart immediately below for coil amp draw vs amp rating).
- If using a high wattage regulated mod, use a 20 - 30 amp CDR IMR battery, which ever your mod's manufacturer recommends. The processor's amp limit determines the amp requirement in this application, not the atomizer resistance:75W or higher, we recommend the Sony VTC4 2100 mah 30 amp CDR.* Coil amp draw from Ohm's Law calculations for Mechanical Mods:
40W-75W = LG 18650HG2 3000mah 20Amp CDR
Under 40W = LG 18650HG2 3000mah 20Amp CDRSamsung 18650-25R, 2500 mah 20 amp CDR (green wrap if you can, blue wrap is just fine)
LG 18650HE2 2500 mah 20 Amp CDR
Sony 18650VTC5 2600mAh 30Amp CDR (* tested as only a 20 amp CDR)
AW 18650 3000 mah 20 amp CDR
Samsung INR18650-30Q 3000mah 15Amp CDR
AW 18650 3000mah 20 Amp CDR
1.0 ohm = 4.2 amp draw
0.9 ohm = 4.6 amp draw
0.8 ohm = 5.2 amp draw
0.7 ohms = 6 amp draw
0.6 ohms = 7 amp draw
0.5 ohms = 8.4 amp draw
0.4 ohms = 10.5 amp draw
0.3 ohms = 14.0 amp draw
0.2 ohms = 21.0 amp draw
0.1 ohms = 42.0 amp draw
0.0 ohms = dead short = battery goes into thermal runaway
For example, I would not use a 10 amp battery for a 0.4 ohms coil (Type B above) on a mechanical mod because that 0.4 ohms resistance will draw 10.5 amps, which is over its continuous amp limit of 10 amps (continuous discharge rate). The above calculations from an Ohm's Law Calculator tell me that a 0.8 ohm build is as low as I would want to use with a 10 amp battery allowing for a wider margin of safety.Everyone is free to set their own parameters, and I can only say what mine are. I try to never exceed 50% of the CDR (continuous discharge rating) of a fully charged battery (4.2v). So with a 10 amp battery, that 50% would be 5 amps continuous -- a 5.2 amp draw from a 0.8 ohm coil).
The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries c rating (amp limit). So down the road, your 20A battery may only be a 10A battery.The batteries we have available can be quite safe if you use the right batteries for the right application and do not abuse them beyond their recommended amp limit. Most bad battery incidents result from user error, wrong calculations, ignoring safe battery practices, or using a mod without adequate vent holes for a battery which goes into thermal runaway.
You may be placing a lot of faith in a cheap ohm reader in making a precise and accurate reading to a tenth or hundredth of an ohm. The most accurate and recently calibrated digital multimeters can cost over $1000.
A loose post screw holding your coil on your RBA can drastically lower your coil resistance by as much as 0.5 ohms (from personal experience).
At the time of this writing (July 2015), there are no mod batteries that can deliver more than 30 amp CDR. Any advertisement of over 30 amps is either marketing hype or a pulse discharge rating (a spec we choose not to use).
A battery venting in thermal runaway will release extremely hot gas, toxic chemicals, and rarely flames. Once this chemical reaction begins, there is no stopping it. The gas can build up inside a mod, and if there is inadequate venting the mod becomes a little pipe bomb.
Ultra low resistance coils
August 2014: We have now had the first confirmed mechmod explosion due to sub-ohming, which took place at the recent VapeBlast event. The device exploded, blew a hole in the ceiling 20 feet above, brought down a ceiling tile, and burnt a hole in the floor. As this was witnessed by dozens of people (also, the explosion was heard by a hundred people or so) and the photos are widely available, it is impossible to deny that it occurred. It seems lucky that no one was hurt; indeed the mechmod owner ran away in order that if any injury occurred he wouldn't be held accountable and to avoid paying for the damage. As the device became hot he threw it down, then it exploded. The incident occurred at a Cloud Contest although it is not known if the vaper who caused the explosion was a bystander or a competitor; since he was clearly stressing-out his rig it seems possible he was about to compete.
What can be learned from this
An incident like this is caused by a chain of design errors, user actions, and possibly a battery fault.
- Sealed metal tubes will probably explode if a battery vents violently
- Small vents at the bottom of the tube are useless, only very large gas vents near the top have a good chance of preventing an explosion
- Building coils lower than 0.2 ohm will raise the amp draw exponentially and this increases risk - the power graph shows a significant change at 0.2 ohms and starts to climb vertically as resistance is reduced further
- Using cheap batteries with ultra low res coils is a certain route to high risk - it needs 30 amp batteries of guaranteed high quality
- Using a 26650 cell is intrinsically safer as it can take a higher load
- Using long draws or machine-gun draws to create monster clouds stresses the battery much more
- Cloud Contests are events where people put ultra high stress on their rig to create monster clouds; if spectating, you could consider standing at the back of the room to stay safe
- If you run a Cloud Contest then you should probably check that your personal and business insurance is really, really good and is appropriate for dangerous sports
- People are now discussing the safety (!) involved with putting 100-amp pulses on their batteries in order to create the biggest clouds with the lowest resistance coils; there is only one way this is going to go and you don't want to be within the explosion radius: someone may have a counterfeit battery, or one that is just too small for this extreme usage mode together with ignoring the device getting warm or even hot.
What's left of a mechanical mod after its battery went into thermal runaway
Deeper Understanding of Mod Batteries Part 1
For those readers who want to learn the chemistry differences between IMR, IMR/hybrid, and ICR batteries. What do those numbers and letters on batteries mean? What's an amp rating (CDR) and why is it more important than the mAh rating when choosing a battery for vaping?Deeper Understanding of Mod Batteries Part 2
Protected vs unprotected batteries - what's the difference? Ohm's Law 101. What is an AW battery? What is an inline fuse? What is stacking batteries?
Ohm's Law for Vapers
My attempt at explaining Ohm's Law in simple layman terms and how it relates to vaping.Explain It To The Noob: Ohm's Law Calculations
As simple as it is to use, some people have a tough time grasping the concept. Warning: Includes graphic photos of mod explosions.
RECOMMENDED 18650 HIGH DRAIN IMR/HYBRID BATTERIES
Panasonic or Orbtronic 18650PF 2900 mAh 10 amp CDR (same cell)
AW 18650 2200mah 20 amp CDR IMR/hybrid (new 2015)
AW 18650 3000 mah 20 amp CDR IMR/hybrid (new 2015)
Samsung 18650 2500mah 20 amp CDR IMR/hybrid (Samsung has recently changed the older blue wrap to a green one.)
LG 18650HE2 2500mah 20 amp CDR IMR/hybrid
LG 18650HG2 3000 mah 20 amp CDR IMR/hybrid
LG 18650HB6 1500 mAh 30 amp CDR IMR/hybrid
Sony 18650 VTC4 2100mah 30 amp CDR IMR/hybrid
RECOMMENDED 18490/18500 IMR BATTERY"new" AW 18490 1200 mah 18 amp CDR IMR/hybrid
RECOMMENDED 18350 IMR BATTERY
"new" AW 18350 IMR 800 mah 12 amp CDR IMR/hybrid
*Avoid purchasing counterfeit AW batteries. The "new" (2015) AW IMR's have a silver/black AW hologram sticker and a black stripe around the bottom end covering about 40% of its diameter.
Tensai 18350 IMR 700 mah 14 amps CDROrbtronics 26650 5200mah 20 amp CDR IMR
RECOMMENDED 26650 IMR BATTERIES
Panasonic CGR26650A 26650 mah 50 amp CDR battery (if you can find them)
Menke 26650 3500 mah 20 amp CDR IMR
Efest 26650 4200 mah 20 amp CDR IMR
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IMR Battery Specification Comparison
A Beginner's Guide to Lithium Batteries
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Battery Specifications and Online Calculators
Exactly why 18650 battery names like VTC4, VTC5, Samsung 25R, are confusing everybody
Green Samsung 18650 25R5 vs. Blue 25R2
Best 18650 Battery (2015)?
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