How to charge batteries safely


In this article, we will be breaking down the various types of batteries and more importantly how to charge, maintain and improve their life-span. There won't be any talks about eliquid, vape juices or even vape liquid. For more information on these, you could check out our article here, but as always, a trip to one of our vape shops in London could be even more helpful.

As always though, we try to cater to all different vapers across the UK and the world in fact, so whether you are just deciding on making the switch from smoking traditional cigarettes to starting to use e-cigarettes, here at the UK ECIG STORE vape shop we've got you covered!

We all know how hazardous to your health tobacco cigarettes are, especially after knowing all the harmful chemicals mixed into them and so on…

There's a huge variety of vaping batteries available on the UK Vaping market, including Samsung, Sony, Golisi and Vaping Outlaws to name a few but, how did they come about in the first place?


Batteries used in E-Cigarettes were originally adapted from rechargeable batteries, mainly used in flashlights and other devices but we've come a long way since then!

Battery type 18350

Today’s batteries come in all different shapes and sizes, including 18350, 18490 / 18500 and 18650 batteries were available, whilst some of the newer devices are designed to be used with single or dual variations of 18650, 20700 or 21700 batteries. In some cases, mods come with battery adapters, making the vape mods cross-compatible with various sizes of batteries.

Battery type 18650 and 21700

So you've purchased a new set of batteries, should you use them straight away or not? We always recommend fully charging (4.2V) and then fully draining the batteries back down to 3.7V. The reason for this is because rechargeable batteries are considered to be safest between the above-mentioned voltages.

A phenomenon called “Memory effect” also comes into play at this point. The repeated charging and discharging of the batteries from 3.7V to 4.2V and vice versa, prompts the battery’s chemical make-up to assume this as standard. This means that the batteries are “programmed” to work at their optimum performance and hold the best possible charge at those voltages.

Battery charging cycle

Once the battery has been drained, you can recharge the battery up to 4.2V once again and continue to repeat this process going forward. Some variable wattage/voltage devices have a “low voltage protection” circuit built into the device, which may not let you fire your e-cigarette if the batteries do not have enough charge in them. If this does occur then simply remove the batteries, charge them fully and then insert them back into your device.


The normal lifespan of an external battery tends to be between 6 - 12 months but if you notice the batteries are not charging up to 4.2V which can appear as 4.19V or 4.18V on the display of the charger, then it is time to consider replacing your batteries with brand new ones. We would also advise replacing your batteries if they are damaged in any way for safety reasons.

More on Battery Types

The most common type of battery would be the 18650 series of batteries, which are so-called because they measure 18mm in diameter and 65mm in height. 18650 batteries can vary in capacity (mAh) which is normally between 1800mAh - 3000mAh and can have amp ratings between 10A - 35A depending on the brand and type of battery. The higher the amps in a battery, the safer is tends to be, and an Amp rating of 20 above would be highly recommended.

Vape kits also come in a wide variety but depending on the one you may have, it will either have an internal battery or use external batteries. If your e-cig kit has an internal battery these will normally be charged using a USB or USB-C cable depending on which option your device supports and would normally take roughly between 2 - 4 hours to charge the battery fully. These batteries tend to make the users vaping experience simpler, by eliminating the need to remove them from the device. Not having an external battery charger may also be a bonus for some people, although we tend to prefer them due to their inbuilt circuitry and faster-charging speeds.

Although most Electronic Cigarettes have USB ports only a handful are intended to be charged this way. They are usually intended for firmware upgrades. If your batteries are removable we recommend you use an external charger such as the Vaping Outlaws VOX1 Battery Charger.

If your device uses external batteries, (which I believe is a better option and personally choose to use) you also have the option of carrying a variation of batteries, for use within your mod. Due to the large choice of batteries available online, sometimes even the most advanced vapers can easily get confused which batteries are the best option to use for the device they have.

I personally use Molicel P26A 18650 due to their 2600mAh battery capacity and a pulse rating of up to 25 Amps. I also use these since I believe them to be the best for my Aegis legend mod. As of when this article is being written, these particular batteries are Samsung’s second most powerful 18650 batteries and I find the balance between battery life and amp rating to be perfect for my particular vaping needs.

Charging Battery

When it comes to charging any batteries externally, it is always wise to use a good charger and there are many available. There are some huge names to look out for within the world of vaping battery chargers such as Nitecore or Xtar, which are used by myself and other colleagues in the office as our first choice and first recommendation to beginners. Depending on the number of batteries you require, there are most certainly differently sized chargers on the market.

Ranging from single bay chargers such as the VOX1 charger by Vaping Outlaws, all the way up to the huge 6 bay Xtar MC6 Queen Ant charger and there is everything in between too. The most commonly used chargers would be 4 bay chargers and the best one I have come across so far would be the Nitecore DigiCharger D4. This is my own personal preference as it has the compatibility to work with almost all types of battery (IMR, Li-ion, Ni-MH / Ni-Cd and LiFePO4) and can accommodate a huge selection of batteries, due to its spring-loaded contacts. You are also able to charge different batteries at the same time within the D4 charger as each bay is independent. (For example; you can charge 2 x 18650 batteries, and 2 x 18500 batteries at once).

When charging your batteries is always best to ensure that the batteries themselves are not damaged in any way, information on the subject can be I found below.

External batteries tend to vary in charging times, commonly depending on how much life they have in them when they hit the charger. You should never drain your batteries below the 3.7V mark, as this may damage the charge cycle of the battery. If your battery has 3.7V of charge left it should only take 2 - 3 hours to fully charge 2 batteries at the same time (if you have a 2 bay or higher charger) and the batteries will be charged up to 4.2V.

It is always advised to keep the charger in sight when your batteries are charging, so if anything did happen to go wrong, you can remove the batteries quickly and efficiently. One piece of advice I always give to anyone is to never charge your batteries overnight. If anything should happen when you are fast asleep such as a power surge, you would not be able to react, which could result in your batteries, charger or yourself being damaged.

Always remember, each Electronic Cigarette is different and therefore we recommend you read through your product manual to ensure you safely charge your Ecig device.

E-cigarette Battery Safety Guide

The vape industry is advancing at a remarkable rate. We have seen a multitude of devices hit the market. Many of these require an external battery to operate – typically an 18650 battery. Our battery safety guide will help ensure that you keep safe when vaping. Having a reliable battery will ensure your device works correctly and your eliquid is vaporised efficiently to provide you with the best vaping experience. 

Making the switch to vaping can be one of the best things you've done for your health since we all know the dangers of smoking traditional cigarettes. The Cigarette smoke includes around 4000 plus hazardous chemicals at each given time. We offer a wide range of vape juices containing only PG (Propylene Glycol), VG (Vegetable Glycerine) natural flavourings and of course, nicotine if you so require. It's also important to note that these products are not intended for the use of anyone under the age of 18, anyone that is pregnant or breastfeeding etc.

Our mailbox is always open so if you have any further questions about batteries or anything vape related, please feel free to drop us an email at or contact us and we would be happy to answer any questions you may have in terms of ways to stop smoking, starter kits, vape liquids and more. Don't forget our vape shop is always here to help you whether you're looking extra advice on how to safely charge your device or looking for a new set of batteries our team is ready to offer the safest advice we'll be here to help!