How To Use 21700 & 18650 Vape Batteries

Guide To Using External 21700 & 18650 Vape Batteries

What are 21700 & 18650 batteries for vaping? A beginner’s guide to using external li-ion batteries for vape mods safely.

As vaping devices like mods become more and more powerful, powerful external lithium-ion batteries have become more and more common. They can be great for vaping on the go and travelling, offer more power output and can avoid the problem of waiting for your vape to charge before being able to use it.

But this leaves lots of questions about how safe these li-ion batteries are, how long they typically last, whether they can be taken on planes and is it safe to charge them overnight? We’ll answer your questions here!

If you have any questions we haven’t answered in this article, leave a comment at the bottom of the page and we’ll update the article with answers!

What is a 21700 & 18650 battery for vaping?

Lithium-ion batteries, sometimes known as Li-ion cylindrical cells, are used in many electrical devices including vape mods, torches and phones. They come in a range of sizes and can provide varying levels of wattage and amperage depending on the battery and brand.

Eco-Vape stocks both 18650 and 21700 batteries on our online store, which are the most common external batteries used in vape mods. You can also purchase external battery chargers to quickly recharge multiple batteries at a time.

Are lithium ion vape batteries safe?

When handled correctly, 21700 & 18650 lithium-ion batteries are safe to use. However, worn-out or damaged cells can be dangerous and lead to short-circuiting. Take care to check the protective cover on your batteries every time you use them.

If you notice any tears or damage on the battery sleeve, or that the insulator rings have degraded, then do not use the battery. You can purchase battery sleeves/covers and replacement insulator rings separately from reputable vendors to replace any that are damaged.

Damaged sleeves or insulator rings can lead to a direct short circuit, causing a fire, explosion and harming people and leading to damage to property. It’s important to also check the contact ends for any debris or dirt too and keep them clean.

Are unprotected lithium-ion batteries safe?

No, you shouldn’t use lithium-ion batteries if they do not have a protective cover. This includes 18650 and 21700 batteries which are often used in vape mods. If unprotected, the batteries can short-circuit and lead to fires or even explosions.

How long does a vape battery last?

If you’re using your 18650 batteries for a vape device, the time it takes to empty the battery will vary depending on usage. If you vape often and take long, extended draws at a high wattage, a 18650 battery can drain in just a few hours.

21700 batteries will last longer than a 18650, though they will also drain quickly if frequently used at high wattages. We recommend using 21700 batteries if you’re a heavy vaper using a low resistance, sub ohm device (especially DTL), as they will last longer at higher wattages needed for sub ohm coils.

However, if used at lower wattages and less frequently, 18650 and 21700 batteries can last a full day. It’s a good idea to have a few spare batteries and an external charger, so you always have a fully charged spare ready to go whenever you need.

Can you take 18650 vape batteries on a plane?

Yes, you can take your lithium-ion batteries on a plane, although it depends on which company you fly with and whether you store the batteries in your handheld or check in luggage.

With most airlines, you can carry up to two spare vape batteries (and one inside the device) in your handheld/carry on luggage, with some allowing up to 4 spare batteries in handheld luggage. Make sure they are in protective casing and do not show any signs of damage.

It’s important you check the restricted items list for your airline before travelling to make sure you abide by their safety regulations.

Here’s a list of airlines that allow spare vape batteries to be carried in hand-held luggage.

Flybe – Maximum of 2 spare batteries (plus one inside the device).
Ryan Air – Maximum of 20 lithium-ion batteries (part 8.4.3).
Easy Jet – Maximum of 2 spare batteries (plus one inside the device).
British Airways – Maximum of 4 spare batteries (plus one in the device).

Checklist to take vape batteries on planes

Ensure the batteries are not damaged in any way (no scratches or tears in the protective cover, insulator ring present and intact).
The batteries are kept away from any liquids and are in secure packaging.
If the battery is inside a device in your check in luggage, ensure the device is switched off and can’t accidentally turn on.
Spare batteries are not usually allowed in check-in luggage. Take them in your carry on luggage instead.
Lithium-ion batteries taken on planes must not exceed 100 watt hours (you can calculate this by dividing the mAh rating by 1000, then multiply it by the voltage).

Can you recharge 18650 vape batteries?

Yes, most external 18650 and 21700 vape batteries can be recharged, though it is important to check the manufacturer guidelines to make sure first. You can buy external battery charging bays, including single, dual and quad bays that hold up to four cells.

External battery chargers are recommended to recharge lithium-ion batteries. Though they can be charged internally in some devices, this can degrade the cell faster and over time can reduce the performance of the battery.

Always charge your 18650 or 21700 batteries to full before using them again to help maintain the performance of the battery. Don’t allow the battery to empty completely, as this can also reduce battery performance over time.

How long does it take to charge a vape battery?

This depends on whether you use an external battery charger or if you charge the batteries internally within a device. Using an external vape battery charger, like the XTAR Quad Bay, is the best way to recharge external vape batteries.

Using dedicated battery chargers helps to prolong the life of your vape batteries, are packed with safety features and can fully recharge a 21700 battery in less than an hour.

Some vape mods, like the Vaporesso Target 100, feature a USB Type-C charging port which allows the user to charge the device with the battery still inside.

This typically takes longer to charge to full and we don’t recommend charging vape batteries internally as it can lead to a reduction in battery capacity over time.

Is it safe to charge 18650 batteries overnight?

We do not recommend charging lithium-ion vape batteries overnight. You should never leave external batteries unattended when charging, in case the device or batteries short circuit or fail and cause a fire or explosion.

Most external battery recharging bays feature a number of safety features to prevent overcharging or detect faulty batteries. However, this does not mean you should leave them unattended, especially when sleeping or away for extended periods of time.

Can you fix a 18650 or 21700 battery sleeve/wrap?

If you notice damage to the sleeve of a lithium-ion battery, you can purchase a new sleeve to re-wrap the battery and ensure it is fully protected. You can also purchase insulator rings to replace any that are damaged on your lithium ion battery.

Li-ion cylindrical cells are similar to the batteries used in many everyday devices like mobile phones and are generally considered safe, however there are serious risks to personal safety arising from improper use.