(9) Battery Basics for Mods; the Ultimate Battery Guide
If you are considering purchasing a particular 18650 battery, just remember that...
...there are none with a true continuous rating over 30A.
...there are none rated at 3000mAh with a true continuous rating over 20A.
...there are none rated over-3000mAh with a true continuous rating over 10A.
...pulse or battery company "max" ratings are useless and can't be used to compare batteries.
There is a LOT of technical information in this blog. I have tried to simplify the information for the average reader. Please take a few days to read over and process this information to avoid information overload.
Li ion technology remains our best solution for a high current rechargeable battery. It's not perfect, and can fail, at times spectacularly. It can fail due to mishandling, internal manufacturing defects, to looking at it funny. Proper care and treatment keeps failures to a minimum, but even with the best of intentions, "energetic release of energy" may still occur.
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 (Lithium Manganese)
- IMR/Hybrid batteries (new sub-class of IMR, and today's most common/recommended battery)
- protected ICR Li-Ion (Lithium Ion)*LiPo (Lithium polymer) 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 or IMR/hybrid (INR) 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.
There are risks with these batteries if misused or short-circuited, and there have been several incidents and some injuries. But this is a common challenge across many types of battery-powered devices.
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.
Modern INR batteries are hybrid IMR chemistry, still high drain and safe chemistry. This is the type of battery most popular and most recommended for vaping purposes.
An Ultrafire protected ICR battery in thermal runaway
A LiPo battery in thermal runaway
An IMR/hybrid battery forced into thermal runaway merely vents gas (no flames or explosion)
Guide to Battery Specification Terms:
Batteries can generally be broken down by two major characteristics or specifications: 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 one company to another company impossible, and therefore should never be relied upon.
The CDR isn't a suggestion.
It's the safe operating limit of the cell.
Basic rule of thumb at the moment, to get CDR amps you have to sacrifice Mah and run time, to get Mah and run time you have to sacrifice amps and CDR. You won't find a battery which has both the highest amp rating and highest mAh capacity; that's the way it works with batteries.
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 amp" specs. Efest, IMREN, and the "---- Fire" brands are the worst perpetrators of this practice. Don't fall victim to their advertising scams.
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 choose batteries by their continuous rate, never for their burst. This is the danger of sub-ohming and not knowing the ins and outs of your batteries.
Battery Amp Ratings: Continuous vs Pulse Ratings
Battery pulse ratings are useless! | E-Cigarette Forum
There are no 18650 batteries with a genuine rating over 30A!
Are You Using a ReWrap Battery?
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 and some you can’t. I will give a quick rundown of them and what makes some more recommended than others. I recommend buying only the batteries from the list below, paying attention to model numbers and their specifications. The manufacturer's amp rating is listed first, and Mooch's test results follow below that rating.
If your battery is not shown in Mooch's Recommended Batteries chart below, its because his tests revealed that it didn't meet its advertised specifications, or became too hot during his bench testing to be considered safe.
Our ECF buddy and battery expert @Mooch has been doing some independent battery testing. Before you purchase a particular battery, look for the results of how that battery tested in the below link:
Mooch has written his own blog with some useful tips on batteries.How can we extend the life of our batteries?
When should you replace a battery?
What is battery internal resistance?
Li-Ion Battery Chemistries - What are the differences in their safety?
Calculating battery current draw for a regulated mod
List of Battery Tests
Mooch talks about vaping batteries
How to Choose Your Batteries by DJLsp Vapes
- 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, Efest, Imren, MXJO, and Vappower brands, among others. Independent tests have revealed that these have over-rated specifications from what is advertised. Most of these brands are considered "re-wraps".What is a "Re-Wrapped Battery"?
There are many battery companies that are not actually manufacturers, but are simply companies who rebrand others' batteries. Meaning, they do not make their own cells and are just buying cells from other manufacturers and “rewrapping or rebranding" them with their own plastic wrapper that has their own brand name and their own logo.
Most rewrapped batteries are Chinese brands. The first thing vapors must realize is that many of these brands have nothing to lose, and can make greatly exaggerated claims regarding performance with no bad fall back. For example ultrafire will claim 6000mah capaicty in cells that are tested to be only 1000mah. Of course the other grossly exaggerated stat is amp rating...and to sell to vapors, many of these companies will make outrageous claims.. We really recommend that the consumer stay away from all re-wrapped batteries. Here is a list of battery brands highly suspected of being re-wraps:
- 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. Do not harvest batteries from old laptop computers; they probably used the wrong type of battery (ICR chemistry).
- Be cautious when shopping for batteries. Unprotected ICR batteries should NEVER be used in a mod. Be aware of fake AW, Lg. Samsung, and 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.)
What's the deal with Sony VTC Batteries?
Sony VTC Batteries are Back!
Sony 18650 Cells | IMRbatteries.com
- 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 2.5; 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 charger 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.
Guide to Choosing a Li-ion Battery Charger
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.
Charging external batteries on the mod
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.
(The above suggestion is based on anectdotal observation only.)
- 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.
- Newer 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. This chemistry is the most popular and recommended battery for vaping currently.
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. Not recommended for vaping.
CHOOSING THE RIGHT BATTERY FOR YOUR APPLICATION. HOW DO YOU VAPE?
- If you use standard resistance coils (1-3 ohms) in a mechanical (no electronics) or (low wattage/20 watt) regulated (electronic) mod, then you could 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 at least 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 good choice.
- If you use sub-ohm resistance coils (0.2 - 0.8 ohms) on a mech mod or high wattage (20 watts +) 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).* Coil amp draw from Ohm's Law calculations for Mechanical Mods:
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
0.15 ohms = 28 amp draw
0.0 ohms = dead short = battery goes into thermal runaway
On a regulated mod the coil resistance is essentially irrelevant. What dictates the amp draw on the battery is the wattage you set, and the remaining voltage in the battery. The amp draw will increase as the battery discharges.
- Calculating battery current draw for a regulated mod 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.
In the interests of keeping things simple:
If you use a good quality 20 amp CDR battery like the Samsung 30Q or the LG HG2 then you are good for 60 watts per battery. If using a 2-battery regulated mod, your good for 120 watts as you have two batteries. If you are using a 3-battery mod, you're good for 180.
If you use a single 30 amp CDR battery like the LG HB6 you are good up to 90 watts; with a pair of 30 amp CDR batteries you could safely do 180 watts assuming the mod cuts off when the batteries reach 3.4 volts.
60W or higher:LG18650HB6 1500mah 30 amp CDRLG18650HB2 1500mAh 30 amp CDR
LG18650HB4 1500mAh 30 amp CDR
For more in-depth information on mod batteries, see:30W-60W:
LG 18650HG2 3000mah 20 amp CDR
LG 18650HE2 2500 mah 20 amp CDR
Samsung 18650 30Q, 3000 mah 20 amp CDR
Samsung 18650-25R, 2500 mah 20 amp CDR
Sony 18659VTC6 3000mAh 20A CDR
Sony 18650VTC5A, 2500 mah 25 amp CDR
Sony 18650VTC5, 2600 mah 20 amp CDR
Sony 18650VTC4, 2100 mah 23 amp CDR
AW 18650 3000 mah 20 amp CDR
On a regulated device the resistance of the coil is irrelevant. Regulated mods separate the input and output voltage, in other words they separate the battery from the atomizer. The only relevant value is the wattage, and the remaining voltage in the battery. The wattage is generated by the mod by multiplying the volts by the amps. As the voltage falls, the mod will increase the amp draw to maintain the selected wattage from the remaining voltage level. You need to know the amp draw at full charge, and when the battery is discharged as this value will be the highest. Most regulated mods are about 90% efficient, so you will also need to factor this loss into your calculations as it will marginally increase the amount of amperage pulled from the battery.
To find the amp draw use I=P/V (-10%)
50w divided by 4.2v equals 11.9 divided by 0.9 = 13.22 amps
50w divided by 3.2v equals 15.6 divided by 0.9 = 17.33 amps
Here's a function within Steam Engine that calculates battery draw for mech and regulated mods.
The recommendations at the vaping website Pagasus Battery Revolution (see above video) are too liberal in my opinion concerning amp limit specifications. I recommend a much higher margin of safety for sub-ohm vapers.
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 decreases, so does the battery's c rating (amp limit).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.
The battery's internal resistance increases, too.
The capacity loss reduces their run time directly. The increased internal resistance increases the voltage sag you see from them, effectively decreasing their run time even further.
So down the road, your 20A battery may only be a 10A battery.
A large percentage of the Samsung, Sony, LG cells are used in multi-cell configurations, i.e., battery packs in hybrid automobiles and cordless power tools. These battery packs have their own battery management system (BMS) that ensures configurable, consistent protection at desired current, voltage, and temperature settings to ensure long battery pack life. As vapers, we are primarily using single battery cells alone by themselves, which often means we may be using these single cells at or above their recommended specifications for a single cell. This application is not the manufacturer's intended use for these cells.
multicell battery pack with BMS (battery management system)
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
AW 18650 3000 mah 20 amp CDR IMR/hybrid (new 2015)
Samsung 25R 18650 2500mah 20 amp CDR IMR/hybrid (Samsung has recently changed the older blue wrap to a green one.)
Samsung 30Q 18650 3000mah 20 amp CDR IMR/hybrid
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
Sony 18650 VTC5A 2600mAh 25 amp CDR IMR/hybrid
Sony 18650 VTC6 3000mAh 15 amp CDR IMR/hybrid (*tested to be 19 amp CDR)
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 (Enerpower)18350 IMR 700 mah 14 amps CDR
RECOMMENDED 26650 IMR BATTERIES
IJoy 26650 4200mAh 40 amp (*tested to be 30 amp CDR)
Brillipower 26650 4500mAh 80 amp (*tested to have 25 amp CDR )
Orbtronic 26650 5200mah 20 amp CDR IMR
Green Efest 26650 4200 mah 20 amp CDR IMR
MNKE 26650 Orange 3500mAh 35 amp (tested as a 25 amp continuous)
MXJO 26650 3500 mah 35 amp (tested as a 25 amp continuous)
AWT 26650 4500 mah 75 amp (tested as a 25 amp continuous)
BASEN 26650 4500 mah "60 amp" (tested as a 25 amp continuous)
Mods, Batteries, & Safer Vaping
PBusardo's Mod Battery Information Guide
IMR Battery Specification Comparison
A Beginner's Guide to Lithium Batteries
Are You Using a "Rewrap" Battery? Exposing The WORST Brands In ...
18650 Battery Buying Guide for Vapor Users
What does IMR mean?
Sub-Ohm Vaping: Discussion, Safety, Battery Info, Warnings
Battery Data | Deus Ex Vaporis
God of Steam's Getting Started: Battery Basics
What does a battery's C Rating mean?
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)?
Best 18650 Battery for 0.2 ohm?
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