18650, 20700 & 21700 Batteries O Battery Chargers O Battery Accessories

Battery Safety Information

18650, 20700, 21700 Batteries are not like your remote-control AAs. They are much more powerful cells that need to be handled carefully. And while battery safety tips may seem like common sense to those who are in the know, new users are often handed a device and a couple of 18650s without any advice on how to properly handle them.

Read on to find out the basics of battery safety, but bear in mind that this is not a mechanical device safety guide; for that, you will need a solid understanding of Ohm’s law and much more info than what can be covered in this beginner’s guide. But if you own a regulated device that is powered by batteries such as 18650s or 21700s, this guide is for you.

Keep wraps intact

Always make sure that the wraps of your batteries are in pristine condition. If you notice a nick on the battery wrap, the safe thing to do is to re-wrap it. Battery wraps are very affordable and very easy to put on. If you don’t have wraps, visit our store to get them wrapped for free and it won’t take more than a couple of minutes. Check out the tutorial below on how to quickly and easily rewrap your batteries.

Use the right batteries

Some batteries are better for low wattage usage, others are better for sub-ohm usage, and others are not supposed to be used at all. When picking batteries for your device, make sure that they come in the appropriate specs. Don’t just read the ratings on the wraps, as those are often misleading. Check for independent battery reviews, and always stay below your battery’s CDR (continuous discharge rating).

Use battery cases

Never throw batteries in pockets or bags when not in use.  Get yourself some affordable plastic battery cases instead, as unprotected batteries might short circuit when they come in contact with metal objects. This may cause your battery to vent and potentially explode. Battery cases are a great solution for carrying your cells and they come in a variety of materials and designs.

battery cases

Watch out for counterfeits

Counterfeit batteries are unfortunately a thing, with the big three (Sony, Samsung, Panasonic) being the most commonly counterfeited brands due to their higher price tag. Always buy batteries from reputable vendors, as those will go out of their way to make sure their batteries are authentic.

Use a dedicated charger

Charging your batteries directly in your device is possible with most devices nowadays, but it’s always safer to use a dedicated battery charger. Stepping up a bit in price will add features such as battery data and health monitoring.

Don’t leave your batteries charging unattended

Even when using a charger, having your batteries charging unattended is never a good idea—especially overnight. Although very rare, battery chargers are electronic devices and failures are not unheard of. Always keep an eye on your charging batteries and place them in battery cases when you are not around.

battery charger

Don’t over-drain your batteries

If possible, try to not completely drain your batteries — lithium-ion batteries tend to lose more capacity the further you let them discharge. Most mods will come with some form of battery level indication. Taking your batteries out to charge before they are completely drained will prolong their life, i.e. the number of cycles you will be able to get out of them.

Avoid extreme temperatures

Batteries can tolerate low and high temperatures, but you wouldn’t want to test their limits. Higher temperatures will strain your batteries, making them age faster (or even vent), while colder temperatures take a toll on battery capacity. Make sure you store them in a cool place away from sunlight and never ever leave them stored in places like the glove compartment of your car where temperatures might exceed their safety range. If you live in an area where the temperatures frequently get extreme, consider carrying your device and batteries in a small insulated lunch cooler—but remember that your batteries should always be carried inside their own battery case.

Use married batteries

If you are using a mod that takes more than one battery, always use the exact same batteries (for example, a pair of Sony VTC5s) and keep them married, i.e. use them in pairs and always together—it’s a safe practice. This will ensure that the cells get the same number of charges/discharges and help delay imbalances in capacity and performance.

married batteries

Replace old batteries

Batteries are only good up to a certain number of cycles (full charge to full discharge). Lithium-ion batteries will start losing capacity and strength when used extensively for long periods of time. If you sense that your battery takes less time to discharge, just replace it. Even if you haven’t noticed something out of the ordinary, replace your batteries after six months to a year, depending on how often you use them.

Recycle old batteries

When replacing old batteries, always recycle them instead of throwing them away. A lithium-ion cell can easily short-circuit in the trash can, which is a serious hazard risk. On top of that, recycling batteries is good for the environment. Keep an eye for battery disposal boxes and follow safety instructions when recycling your old batteries.