(9) Battery Basics for Mods: IMR or Protected ICR?

Published by Baditude in the blog Baditude's blog. Views: 19282

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 battery chemistry are:

  • Lithium IMR or Li-Mn
  • IMR/Hybrid batteries (new sub-class of IMR)
  • 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.)

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.

reference - Rechargeable Batteries

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:

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, and therefore should never be relied upon.

Beware of dubious marketing claims of battery amp ratings by some disreputable vendors and manufacturers.

Purple Efest Batteries Not As Advertised

High Quality, Brand Name Batteries. Batteries are not created equal. I recommend buying only the batteries from the list below, paying attention to model numbers. CDR is the continuous discharge rating in amps.

AW (IMR)

18650 2000mah 10Amp CDR

18650 1600mah 24Amp CDR

18490 1100mah 16.5Amp CDR

18350 700mah 6Amp CDR

18650 2200mah 20Amp CDR(new hybrid)

18490 1200mah 18A (new hybrid)

18350 800 mah 12A (new hybrid)


Imren
Purple 2500mAh 18650 "40 Amp" (*tested as only a 20 Amp CDR)

LG (IMR/Hybrid)

18650HE2 2500 mah 20Amp CDR

18650HE4 2500mah 20Amp CDR

18650HG2 3000mah 20Amp CDR

18650HB6 1500mah 30A CDR


MNKE (IMR)

18650 1500mah 20Amp CDR

26650 3800mah 20A


Panasonic or Orbtronic (IMR/Hybrid)

CGR18650CH 2250mAh 10A

NCR18650BD 3200mAh 10A

NCR18650PF (LiNiCOMnO2) 2900mAh 10A

NCR18650PD (LiNiCoAl) 2900mAh 10A

Orbtronic 18650 3500mAh 10A

Orbtronic 18650 SX22 2000mAh 22A

Orbtronic 18650 2500mAh 21A

Orbtronic 18650 SX30 2100mAh 30A (*tested as only a 20 amp CDR)

Panasonic 26650 CGR2650A 2650mAh 50A

Orbtronic 26650 5200mah 20A

* 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 low drain applications like flashlights.




Samsung (IMR/hybrid) (LiNiCoMnP)

INR18650-30Q 3000mah 15A

INR18650-20R 2000mah 22A

INR18650-25R 2500mAh 20A


Sony (IMR/hybrid)

18650VTC4 2100mAh 30A

18650VTC5 2600mAh 30A (* tested as only a 20 amp CDR)

26650 2600mAh 26A


Efest (IMR)

18650 2250mAh 10A

18650 2000mAh 10A

18650 1600mAh 30A

18490 1100mah 8.8A

18350 800mah 6.4A


Efest (IMR/hybrid)

purple 18650 2500mAh "35A" (*rebranded LG18650HE2 2500mAh 20 amp CDR)

purple 18650 2100mAh 30A (* rebranded Sony 18650VTC4 30 amp CDR)

purple 18650 2100 mah "38 Amp" (* tested as only a 20 amp CDR)

purple 18500 1000mAh 15A

purple 18350 700mAh 10.5A

Efest 26650 4200mAh 20A

Our ECF buddy and battery expert @Mooch has been doing some independent battery testing: :thumbs:


  • Lower Quality Brand-Name Batteries. Trustfire, Ultrafire, and Surefire are a lower-tier name brand battery in terms of quality and safety. Not recommended.


  • 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.


  • 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.
[​IMG]

  • 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 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/Hybrid batteries.
  • 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 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?
  • 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.
  • 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:
If you're going to vape at 75W or higher, I recommend the Sony VTC4.

From 40W-75W = Samsung 25R, green wrap if you can, blue wrap is just fine.

Under 40W = LG HG2 or Samsung 30Q, almost identical in performance.
* 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
0.0 ohms = dead short = battery goes into thermal runaway




[​IMG]
The recommendations in the above pic from Battery Revolution 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 degrades so does the batteries c rating (amp limit). So down the road, your 20A battery may only be a 10A battery.

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).
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.

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.


[​IMG]
What's left of a mechanical mod after its battery went into thermal runaway
For more in-depth information on mod batteries, see:

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
[​IMG]
AW 18650 2200mah 20 amp CDR IMR/hybrid (new 2015)

[​IMG] [​IMG]
Samsung 18650 2500mah 20 amp CDR IMR/hybrid (Samsung has recently changed the old green wrap to a green one.)

[​IMG]

LG 18650HE2 2500mah 20 amp CDR IMR/hybrid

[​IMG]
Sony 18650 VTC4 2100mah 30 amp CDR IMR/hybrid

[​IMG]
Orbtronic 18650 SX30 2100 mAh 30 amp IMR/hybrid (* may be only 20 amps CDR; see Mooch's test results)


RECOMMENDED 18490/18500 IMR BATTERY

[​IMG]
"new" AW 18490 1200 mah 18 amp CDR IMR/hybrid


RECOMMENDED 18350 IMR BATTERY

[​IMG]

"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.


Resources:

Mods, Batteries, & Safer Vaping

PBusardo's Mod Battery Information Guide

IMR Battery Specification Comparison

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)?
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