The Ultimate Guide to Vape Batteries

Vaping Batteries

Vaping has come a long way since its inception, and one area that has helped to make vaping what it is today is the use of high-powered batteries. But for the uninitiated, the whole vaping battery scene can create confusion.

This guide covers everything you need to know about vape batteries.

What are vaping batteries?

Here a quick history lesson is needed – Not long after the dawn of vaping, curiosity drove vapers to experiment with the concept, which gave rise to the Mod. The first mods were “modified” devices that used the likes of torch bodies and batteries to power the vaping device.

From this beginning, a whole industry was born, and the use of batteries and e-cigs became synonymous with each other. Every e-cig needs a battery to power it, and when it comes to the battery, there are two main types of e-cig to consider.

1. Internal Battery

Many mods, pod systems, and pen e-cigs are supplied with an inbuilt battery that cannot be changed. These are often one or more of the 18650 batteries (more about this later), although there are quite a few exceptions that use other types of battery. These are normally charged through a USB port.

The benefits of internal batteries include:

  • Included in cost
  • Simple to use
  • Sure of the right battery
  • No battery chargers required

2. External Batteries

These are used for mods where the batteries can be swapped out and changed. In most cases, you will need to buy the batteries separately when purchasing the mod. The most common type of battery is the 18650, although many mods will use 20700 batteries.

Most mods will take one or two batteries, although some can take more than this. The benefits of external batteries include:

  • The lifetime of the mod is not restricted by the life of the battery
  • Batteries can be charged in advance and swapped when required
  • Faster charge times with quality chargers
  • USB charging also available with many mods

Main types of vaping battery

The batteries used in the vast majority of e-cigs are either 18650, 21700, or 20700. The use of numbers to name the batteries is based on their dimensions, as described below.


This is the most common type of battery used in e-cigs. The numbers in the name denote that it measures 18mm in diameter x 650mm in length. 18650 batteries have a voltage of 3.6v or 4.2v and are usually rated between 2600mAh and 3500mAh.

The higher the mAh rating, the more power the battery can provide. There is a little more detail in this a little further down. Quality is important when buying batteries as cheaper and unbranded batteries will underperform at best and can be downright dangerous at worse.

Always opt for high-quality batteries like the Sony VTC6 3000mAh when making a purchase.


These are so close in dimensions that mods that can handle the size will accept both sizes. As expected, these measure 20 or 21mm in diameter by 700mm in length.

Like the 18650, it is also a 3.6v or 4.2v battery, but the larger size gives it an increased capacity, usually between 3000mAh and 4000mAh. Once again, quality is essential when buying any battery, so always opt for a quality product like the INR 21700 30T when making your purchase decision.

These are the two main types of battery, but some mods now accept bigger batteries like the 26650 size.

Battery Terminology Explained

Now that you understand the role of the battery and the various types on the market for vapers, we can look at some of the terminology used when discussing batteries.

As we have already covered the names and how they relate to the size of the battery, this section will focus on the power and capacity of the batteries.


Most e-cig batteries are either 3.6 volts or 4.2volts. This is the fixed voltage that all vape batteries produce, although through clever circuitry Variable Voltage and Variable Wattage devices can boost this figure to produce higher temperatures and more vape.


Amps or amperes is the rating given to the amount of electricity that flows through a circuit per second. Whilst the voltage is a fixed rating, the amps that flow through the e-cig depends on the setting of the vaping device. For instance, a vaper puffing at a 25w setting will draw fewer amps than someone producing plumes of vape at 50w.


This is the measure of the power that is being drawn from the battery with each puff. It is calculated by multiplying the voltage by the amps, so it is a simple calculation.

For instance, a vaper drawing 6amps with each puff will be vaping at a wattage of 3.6v x 6amps = 21.6watts.

Capacity mAh

mAh is the measure of the capacity of the battery. The higher the number, the longer a battery will last between charges. In e-cig terms, the capacity you should expect from good batteries will be between 2000mAh and 4000mAh.

However, there is a proviso, larger capacity usually means larger sizes, so smaller capacity devices like the Aspire Pod Favostix, with a 1000mAh rating, are still great options when it comes to looking for discreet e-cig options.

Care of e-cig batteries

You can prolong the life of your e-cig battery by following a few simple guidelines:

  • Storage – Batteries don’t like extremes of temperature. Keep them stored in a dry environment with a temperature of between 0° C and 45° C.
  • Charging/Discharging – Keep an eye on the voltage of your battery and try to avoid discharging it to below 3.0v. Frequently letting the battery drop below this will greatly affect its lifespan.
  • Check the sleeve – The plastic sleeve or “wrap” of a battery is a crucial insulation element. These can be easily damaged, and this can cause dangerous short circuits. Battery wraps can be purchased that will shrink wrap over a battery simply by heating with a hairdryer, and this method can be used to replace damaged sleeves.
  • Store in a discharged state – If you don’t intend to use your batteries for a while, then partially discharge them before use.

Summing up

The most important lesson to take from any guide to batteries is that quality is everything. These are large capacity devices and to be safe, always buying batteries that have met the rigorous quality standards of top manufacturers is a crucial factor.

At Direct2U-Ecigs we only supply batteries that come from named manufacturers with great reputations. If you need any advice on what battery or batteries you need, then our friendly team are always on hand to help.