Beginners Guides

Mod Batteries

A basic introduction to batteries covering safety, key terminology, their use and disposal.

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When using larger battery mods (typically built to accommodate 18350/18490/18500/18650 batteries) you need to find cells that deliver a good continuity of output and recharge safely.

Apart from some variable wattage mods that contain their own non-replaceable battery, the vaper’s choice is the Lithium-ion battery. Many of your devices in the house also use Lithium-ion batteries: mobile phones, laptops, tablets, digital cameras, cordless drills and hedge trimmers for example.

They are made from a compound of the metal Lithium (that is flammable), sometimes you will see a warning displayed on the case of the battery. A failing battery can vent dangerous gases or cause a fire. This is why it is essential to buy the best battery you can afford and ensure that it is recharged correctly.


IMR/ICR batteries

These are the recommended types for use in electronic cigarettes. They are made from a different compound compared to other Li-ion batteries, lithium and manganese. They have a lower internal resistance; this means that they stay cooler and can deliver a higher current.

Lithium-ion batteries are often referred to as Li-ion batteries. Rechargeable Li-ion batteries come in two varieties: protected (ICR) and non-protected (IMR). The protected batteries are longer because they have a circuit built into them to fail before the battery fails.

IMR batteries are called ‘safer chemistry’ batteries because of the way they handle failure. Instead of exploding, should you have the very rare experience of this, the battery will vent gases instead.

A variable voltage/wattage device has its own circuitry to prevent fails and so you will not need to use an ICR. You can purchase an inline fuse for an IMR if you wish but most users of unregulated mods do not bother. As long as you are operating within the safe limits of the battery you will have no problems.



An 18650 battery means that it is 18mm in diameter and 650mm in height. A 14500 battery means that it will be 14mm in diameter and 500mm in height. Guess the dimensions of the 26650 battery…



The milliampere-hour (mAh) is the measurement of how long your battery will last in use. A higher figure means the battery will last longer.

The true figure for a battery can be much less than what is printed on the side of the battery. An expensive brand will perform better, last longer and be safer in use.

The lower the resistance of your coil the ‘faster’ the energy will flow around the circuit in the mod. This means the current (amps) will be higher. It is important to know what the maximum current your battery will withstand is and to appreciate how to use Ohm’s Law.

A “short” is when there is a problem and no resistance exists in the circuit. Electricity flows through the battery so quickly that it gets very hot, can expand and vent. If the mod does not have vent holes this can cause a very big problem for safety.

A battery that has been subjected to a short may have had its internal chemistry altered and no longer be safe. Although it might pain you to recycle a £10 battery it is the sensible thing to do.


What are the popular brands?

Efest, AW and MNKE are reliable and popular, but make sure you buy from a recommended supplier, there are many fakes that do not perform (and are not as safe) as well as the originals.

With batteries you really do get what you pay for.


In use

Li-ion batteries start degrading after being manufactured. They will last two to three years from the date of manufacture whether you use them or not. They sensitive to high temperatures as the heat will cause them to degrade rapidly. If you completely discharge a lithium-ion battery, it is ruined.

Use a well-known, reliable recharging unit that will keep your batteries in optimum condition and monitor that they do not overcharge.

*NEVER leave batteries charging unsupervised.


When should I recharge it?

You will notice the performance begin to tail off on an unregulated variable voltage/wattage device, this is the point you need to swap in a new battery and pop the one you were using on charge.

On a variable voltage/wattage device you should consider swapping batteries once the one in your mod reads 3.6volts.



Take your unloved batteries to a recycling centre as they contain metals that will poison the ground if placed into landfill sites.


Battery rules summary

  • Use an IMR battery.
  • Buy from a reputable vendor.
  • Avoid batteries with ‘Fire’ in the name.
  • Do not overcharge.
  • Do not leave a battery charging unattended.
  • Make sure your mod has holes for gases to vent out of.
  • Do not scrimp – buy the best brand available.
  • Always check your resistance of your atomiser before using it.
  • If your device is getting hot stop using it and remove and recycle the battery.
  • If you are concerned about safety then buy a mod fuse or use a Kick.
  • Get rid of your old batteries at the local tip recycling collection point.
  • If you are unsure ask a question on the Planet of the Vapes forum.


...oh, and there are two ends to a battery. Make sure you put it in the right way around :)

Toby Kilroy avatar

Toby Kilroy

Writer at POTV
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Toby has been vaping since early 2012 and has used an array of devices and kit in that time. He sometimes writes up reviews but is often found with his head stuck in pages of code with a confused smile on his face. Toby also helps run his wife's site and has two children. He sometimes fondly remembers having free time and occasionally manages to sneak away to put his head into a good book!

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