Everything you always wanted to know about external batteries

The more advanced and smarter the e-cig device (i.e. advanced mods), the more likely it’ll require an external battery or two – or more – to provide it with the ‘juice’ it needs so you can vape the e-juice of your choice. But to use external batteries, of all vape accessories UK, it’s important to be aware of their ins and outs. And that means, first, being able to distinguish them from internal batteries…

Internal batteries

Internal batteries are battery cells specifically built into a mod device itself and, thus, can’t be removed. An internal battery can only be charged (often via a USB port and cable) a fixed number of times before it becomes incapable of holding any further charge and so is useless. In that case, a mod tat comprises a built-in internal battery will also become useless along with its worn-out battery.

External batteries

Conversely, the lifetime of an external battery, which can be used again and again in an e-cig device from a vape shop London, goes on and on because once it runs out of power it can be switched over with a fully charged alternative and be charged itself, ready to be used again. This system’s especially convenient for vapers constantly on the go and, thus, without handy access to a charging-friendly outlet. You’ll find there’s a welter of external batteries on the vaping market – everything from 26650s to 18650s – yet bear in mind that the larger the battery the larger the device it’ll have fit in, ensuring it becomes increasingly less easy to stash away the device in your pocket.


Well dealing with electrical devices, it’s always important to consider safety and, thus, in turn, so it goes with the batteries you pop into them too. You’d be well advised then to learn about battery safety ahead of purchasing external batteries and a mod that takes them – and, as you may well have imagined, the better brand of battery you choose (and the one with the correct specifications for the device you’re intending to pair it with) the better it’ll operate and the safer, at that.

Never forget that, when used without due care and diligence, external batteries have the capacity to explode or catch fire. To wit, it’s always a good idea to transport them in a carry-case and to ensure they don’t mix with other metal objects (they really don’t tend to get on with them well) and, of course, away from excessive heat. Always re-wrap or, if necessary, throw away a battery whose protective wrapping is damaged; don’t take any chances. And try never to overcharge or over-discharge an external battery.

Generally speaking, though, you shouldn’t be put off using external batteries because of any perceived risk. When deployed in factory-built regulated devices, they should be safe to use when used as directed – even when used at particularly high wattages. When it comes to using external batteries for mech mods or a mod you’ve essentially built up yourself, it’s a different kettle of fish; it’s imperative you understand the ins and outs of the hardware you’re dealing with and, of course, of the external batteries you intend to use with it (i.e. battery outputs and electrical rules as defined by the likes of Ohm’s Law).

Battery marriage

Finally, ‘married batteries’ – what on earth does that term mean? Well, simply, it refers to two batteries that are used together for their entire lifetimes. They can be used if differing devices, but never apart; they always must be used together – and they always must be recharged, as well as discharged, at the same time.

This is because, if a ‘new’ battery and an ‘old’ battery are used together (that is, when two married batteries ought to be), the old battery may discharged below the level of 3.2V, which could damage the battery as well as the mod. So, to avoid, this two married batteries have to be used together and simultaneously in order for their power to be drained at even, efficient and safe rate – and that’s only possible when both batteries are exactly the same; the same model, brand, charge and age.