Charging Safety

Like all lithium batteries, e-cigarettes have the potential to fail, and this often occurs when charging.


News stories about e-cig explosions are shockingly common, and while the problem is a broader one probably more likely to affect your phone or laptop, learning to safely charge your e-cig is essential.


Although there is an inherent possibility of thermal runaway with any lithium battery, the majority of reports thus far resulted from important safety advice being ignored. Following these rules isn’t difficult, and in the unlikely event that you do encounter problems, you’ll be able to catch it early and minimize any damage.


Key Points


  • Don’t leave a charging e-cig unattended; if something goes wrong, you need to be there to deal with it.
  • Overnight charging is asking for trouble; unplug the charger when the battery is powered up.
  • Charge away from sources of heat or intense cold, and keep it away from flammable items and children!
  • Use the manufacturer’s charger where possible, but if not, research threading and power rating carefully to ensure compatibility.

Never Leave Your E-Cig Charging Unattended

This advice is printed in just about every e-cigarette manual you’ll come across, and it’s there for a reason. Things can go wrong during charging, and if you aren’t there to identify it, they can go very wrong. It’s like a leak in a water pipe; it only creates serious issues if you allow the problem to continue unchecked for an extended period of time.


If your battery is overheating and you don’t notice, it could progress to a full-blown explosion or firework-like incident because the charger is still adding more energy into that system.


If you notice the battery heating up or swelling, remove the charger from the USB port or wall socket and place it somewhere safe to cool down.


Don’t Charge E-Cigs Overnight


The night might appear like the perfect opportunity to recharge your e-cig battery, because that way it doesn’t interfere with your vaping through the day. However, for the reasons stated above, it is not advised to leave your e-cig charging overnight.


Overcharging your e-cig can lead to thermal runaway and explosive failure, and no beginner e-cig models will require a 6 to 8 hour charge; ordinarily it’s more like half that.


When your e-cig has finished charging (the LED light on the charger will change color, ordinarily to green), you need to be there to remove it from the charger as soon as possible afterwards.


However, if you have large batteries, like 18650s, that require more than a couple hours of charge time, it’s safe to use something like an intelligent charger. The NITECORE Intellicharger not only automatically detects and adjusts voltage output for each type of battery (Li-ion, Ni-MH and Ni-Cd), it will stop once a battery is fully charged.


Where to Charge Your E-Cig


It’s also important to charge your electronic cigarette battery in a safe location, away from sources of excessive heat and – in the event of any problems – away from flammable materials.


As well as problems with excessive heat, lithium batteries shouldn’t be charged at below-freezing temperature. This is because the non-lithium “anode” becomes coated with plates of lithium, and the build-up can’t be reversed. Over time, this can lead to battery failure.


Additionally, you should always charge your batteries out of reach of children (or pets). Of course, there is little to be worried about if you don’t leave the battery unattended and abide by basic safety precautions, but in the unlikely event of trouble, the last thing you want is a child coming into contact with an overheating battery.


A Guide to E-Cig Charger Compatibility


If you want to guarantee maximum safety, don’t charge your e-cig with anything other than the official charger from the manufacturer. Mixing chargers opens you up for additional risk, so if you’re in any doubt, just stick with the official charger. That said, cross-compatibility is possible with many models and chargers, but it’s important that you research both the power specifications and the threading required beforehand.

In short, most beginner-friendly, pen-sized e-cigs use KR-808D-1 threading and eGo type models use 510 threading, although there are many variations which affect compatibility. A compatibility chart can help you ensure you get the correct threading, but it’s often worth checking for a specific note regarding compatibility on any new charger you buy, because in some cases the polarity on chargers (even with the same threading) can differ. To make things easy for vapers of cigalikes, Magic Mist offers chargers compatible with over 25 e-cig brands.


It’s also important to match up the power ratings on any charger you use. You need to ensure that the charger you use is receiving the input it needs from your USB port or AC adapter (USB cables or pen-drive chargers usually require 5 volts and 500 mA), and that the output is suitable for the device you’re charging. The easiest way to do this is to match the output voltage of your new charger to that of your old one, and ideally find one with the same output current (in mA) too. Pushing the voltage too high can fry your device, but generally speaking, it doesn’t matter too much if the current varies. Too little current from your charger to your device will increase the time it takes to recharge, but the e-cig will only draw the current it needs, so it won’t be overloaded by a higher current output.



E-cig batteries can fail, but – as the example news story in the introduction shows – it normally happens because somebody thought it would be OK to push too much voltage into their device and leave it charging overnight or something equally negligent. The man in that story has had three batteries fail on him because he uses them incorrectly, whereas the vast majority of vapers follow basic safety principles and have no catastrophic failures.