The Vape Store Blog

Charge up your knowledge with our beginners guide to the 18650 battery

The 18650 is the most popular style of battery when it comes to vaping and is used to power many devices available today. If you’re using a device which requires an external battery then more than likely it takes an 18650 battery. Even devices which don’t require an external battery, like the iStick, actually have an 18650 built into the device (but you won’t be able to remove it).

Knowing a little bit about 18650 batteries and how best to use them is valuable knowledge. You can decide which 18650 batteries will best suit your needs, which devices they will provide adequate power for, and the resistance of the coils in your tank that can be used.

You may have been required to purchase an 18650 battery for your new device, and you might have been left wondering why you needed to use this particular battery – rather than the AA or D size batteries you might be more familiar with. Unless you’ve done your research before you made your purchase, these new batteries might seem a little confusing to you.

Ego style battery
Ego style battery

Less than two years ago, it was generally only expert vapers or hobbyists who needed to use 18650 batteries in their devices. The regular every-day vaper didn’t need to worry about it because they were most likely using a simple eGo style battery to power their vape.

The vaping industry has progressed quickly over the last 12 months and with many more high powered devices available there are more devices requiring an external 18650 battery – even beginner level devices.

These batteries are generally safe but need a bit more care than other batteries like AA or D size batteries. So it’s important to have at least a general understanding of these batteries to make sure you get the right battery for your device and to ensure you take proper care of your batteries.

Why do vapes use 18650 batteries?

Outside of vaping, the batteries you’re probably used to buying are AA alkaline batteries which power calculators and toys. Although 18650s are a similar shape and size to these kind of batteries, there’s a lot of difference in the chemistry and technology between the two. AA type batteries simply aren’t able to provide the amount of power required for your typical mod, nor the battery capacity expected.

Let’s take a trip down memory lane

To give you a better understanding about why these batteries are used, it’s useful to know how vaping started in the early days (way back in 2008/2009).

Back then the only types of devices you could buy were the disposable ‘cigalikes’ and cartomisers. These were generally small, low-powered electronic cigarettes which were designed to look like an actual cigarette.

A small vaping community had sprung up around that time across various web sites and they would discuss ways to create more vapour than those devices could produce.

Some members of the community started modifying high powered flashlights to use for their ecigs. They removed the globe and replaced it with an e-cig tank which created a much more powerful vape than they were able to get before.  These flashlights were basically a metal tube to house an 18650 battery and a globe.

This idea took off and it wasn’t long before manufacturers started creating metal tubes specifically designed for vapers. These are known as mechanical mods, and are still quite popular among the vaping community. They contain no electronic circuits and require considerable knowledge to get the best out of them and to ensure that they are used in a safe manner.

The reason higher powered devices are called mods is because they started out as mod-ified flashlights.  These batteries were used because under the right conditions they were able to generate a much higher output than anything else of a similar size and availability.

Most vapers today instead are using the next generation of mods, which are referred to as regulated mods. These have an electronic chip which regulates the output and provides safety mechanisms to avoid overstressing the battery. If you have a device which takes an 18650, has a digital screen and allows you to adjust the wattage, voltage or temperature of your device, then you’ve got a regulated mod.

As devices have become more sophisticated, there is less of a requirement that the user understands everything about battery safety, but it’s definitely useful to have at least a basic understanding of the batteries.

Where else are 18650 batteries used?

18650 batteries were never originally intended by manufacturers to be used for vaping, so what were they designed for in the first place? Well, as discussed earlier, they are used not only in flashlights but also in laptops and electric power tools. More recently they’re being used as the power source for electric cars and electric scooters.

Other types and sizes of batteries

18650s are not the only type of battery used in vapes. Two other common types are the 18350 and the 26650. These are not as popular as the 18650, which strikes a better balance between physical battery size and capacity.


Not all 18650 batteries are the same.

Although all 18650 batteries are the same size and shape, the difference in the technology and chemistry between battery types and brands varies significantly. This means that different 18650s have different maximum power outputs, and you should know which ones are right for your device.

High-amp 18650 batteries are generally safe to use, but remember they were never originally designed to be used to power vape mods. If a battery is overstressed and attempting to power a device at a level it’s not capable of, then there’s a risk it will start venting.

Venting happens to a battery when it’s overloaded. A chemical reaction begins internally which causes it to release toxic gas and eventually catch fire or explode. Obviously this is a situation you want to avoid, and if you’re using a regulated device then the chip inside will significantly reduce the risk of venting… but if you’re not using the correct battery then there’s still a risk you may overstress the battery and cause venting.

What things do I need to look for when I purchase an 18650?

The first thing you want to do is make sure you buy from a known brand such as Samsung, LG and Sony. There are many other brands on the market, but if you stick with one of the big name brands then you’re definitely on safe ground.

The next thing you need to consider is the amp discharge rating of the battery. I don’t want to get too technical here, but the amp rating of a battery determines the load the battery can handle before it gets overstressed and risks venting.

It is recommended that you stick with a battery which is rated at 20A or higher (which is the amp rating of the Samsung 25R batteries).

Let me explain why…

If you’ve been vaping for some time you might know that a lower resistance of a coil will produce more vapour. A device with a 0.5ohm coil will usually produce larger clouds and give you much more flavour than a device with a 1.5ohm coil.  What is essentially happening is that the 0.5ohm coil is drawing more power from the battery, resulting in more vapour being produced from the coil.

At The Vape Store we stock the Samsung 25R and Sony VTC4 batteries which are one of the safest and most reliable 18650 batteries available. They will work fine in all devices we sell and will work great with any regulated device on the market.

It’s all about the AMPS

This is where the amp rating of a battery is important. The amp rating determines how much power (the current) the battery can output without getting overstressed.

Let’s say you’re using a high powered mod and you have it set to 50W and you’re using a Uwell Crown tank with a 0.25ohm coil. This will be drawing a current of around 14 Amps from your battery. If you’re using a battery such as the Panasonic NCR18650PD – which is only rated at 10 Amps – then the current required would exceed the battery capacity and you’ll risk the battery venting.

Samsung 25R batteries are rated at 20 Amps which is well above the 14 Amp limit in this example, so they will perform perfectly fine for this setup.

Battery care and safety

Batteries need to be treated with care to ensure they perform at their best and to also make sure they don’t get damaged, which can increase the risk of venting.

  • They should not be left in direct sunlight or heat. So don’t leave them in your car on a warm day.
  • Don’t drop the battery or knock them against anything.
  • If the wrap on the battery is damaged or broken, avoid using the battery. You can purchase battery wraps which will fix this but don’t assume that a broken wrap is a trivial issue. The underside of a battery wrap, when touching an internal pin in your device, can act as a positive terminal and complete the circuit of the device, thereby firing it.
  • Batteries need to be kept separate and not get in contact with other metal objects, otherwise there’s a risk of shorting which can lead to the battery venting. So don’t pop them in your pocket with things like keys and money in there.

Now you know about 18650s

These are the basics of the 18650 battery. When used properly, 18650s are perfectly safe batteries, providing excellent power and outstanding battery life. But it’s always better to be safe, and with a little bit of knowledge you can make educated decisions about which 18650 batteries to buy, and how best to use them in whichever device you choose.

Shop for 18650s batteries

Marc Callec

Marc Callec


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