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Batteries and Battery Safety

Batteries and Battery Safety

While most vapers take their first steps with devices that use a built in battery, most mods on the market use one of a few kinds of removable, replaceable, and rechargeable batteries. Beyond getting mildly irritated that they usually have to be bought separately, most beginners don’t think too much about the batteries they use in their mods.

In this blog we’re going to discuss how this attitude can be costly and sometimes dangerous, and hopefully teach you guys a thing or two about how to stay safe and keep your batteries in top condition!


What are Lithium Ion Batteries?
Lithium Ion Batteries
The batteries used in most vapes (but not all, looking at you Batpack!) are Lithium Ion Cells designed for high current draw applications. As the name suggests, they store power using a chemical mixture that includes Lithium, a highly reactive type of metal. Li-ion cells, as they are also known, are right at the cutting edge of battery technology, and have become a staple of all the electronic devices that we use every day, from smartphones to laptops to electric cars!

The type of cell used in vapes is almost always what is known as an 18650. 18650 is a size of battery, similar to the AAs or AAAs you may be more used to. There are a fair few companies that make these cells, including Samsung, Sony and iJoy to name a few big players. No Duracell or Energizer here, at least not yet.
Other sizes of Li-ion batteries are available, including the 20700 and 21700 which are starting to gain popularity in the vaping scene
Other sizes of Li-ion batteries are available, including the 20700 and 21700 which are starting to gain popularity in the vaping scene. For those of you wondering, the number is directly related to the physical dimensions of the battery (e.g. 18650 = 18mm x 65mm).

There are many makes and models of battery available, each with different ratings, designed for different use cases. When in doubt, we recommend the Samsung 25R for its output, lifespan, and reliability.

One important figure for your batteries are the capacity, a figure measured in mAh that gives you a rough idea of how long your battery should last. The higher the capacity, the better battery life you can expect! The other figure to note is the Maximum Continuous Discharge Rate, but we will get into that a little later.


Are these batteries safe?
Perfectly safe! Just so long as you take care of them.
You may not know it, but even without vaping you may have been using 18650s very regularly! Many Laptop battery packs are actually just a bunch of 18650s in a plastic case, wired up to some all important safety circuits.

That’s not to say things can’t go wrong. Stories appear in papers every now and then of a mobile phone or vape mod that has exploded in someone’s pocket (or worse, their face!) with devastating consequences. However, almost all cases of battery failure can be traced back to failing to follow just a few key safety points.

Basic Battery Care
The first thing you should do to keep your batteries in mint condition is… put them in the right way up. It seems like a really silly, simple thing, but it can’t be forgotten!
Most devices/mods have protections built in against reversed polarity batteries, so if you did put one or both in backwards then the device simply wouldn’t work. That said, it’s always better to be safe than sorry. Check your device for markings indicating which way up your batteries should be, and if you still can’t tell you can check the manual or look around online.

Though you can expect your batteries to warm up to the touch when in use, be mindful of just how hot they are getting. If they get hotter than usual or too hot to touch, they may well not be safe to use anymore. Don’t store your batteries in direct sunlight, try to keep them in a cool dry place. If possible, store them outside of your device when not in use (battery cases are perfect if you want to throw them in a pocket or bag), and be mindful of leaving them in hot cars!
battery cases are perfect if you want to throw [batteries] in a pocket or bag

Something else that may seem obvious to some of you: keep your batteries clean! Particularly when vaping, there is a chance that your batteries may come into contact with E-Liquid. If this happens it isn’t the end of the world, just give them a wipe with a tissue. Batteries covered in juice are a hazard, as it increases the potential for short circuits which can lead to failure.
Keep your eye out for any marks or corrosion. If your battery starts getting dirty or rusty, stop using it.

Corroded batteryDirty, abused battery

Lastly, if your mod uses two or more batteries you should ideally be marrying the batteries that you use. Keep them in pairs, and make sure that each is only used with its partner. This ensures that both will be charged and discharged the same amount of times, and will help to avoid imbalances that can damage your batteries and your mod.

Charging your batteries
One of the most common complaints you will hear when working in a vape shop is that someone’s batteries aren’t lasting as long as they used to, that they take forever to charge and drain too quickly.

More often than not these kind of faults occur because the battery has not been properly charged. This could be because they are not being charged to full each time, but more often than not it’s down to one simple thing: trying to charge batteries in your vape mod.

Now I know what you’re thinking. My mod has a usb port! When I plug it in, the batteries charge! What do you mean I shouldn’t charge them in my mod?!

Well, with some mods you can charge your batteries through the USB port, but these are certainly the exception rather than the rule and will often advertise this fact on their packaging. The truth is that most vape mods come with a warning somewhere in the manual that politely asks you not to charge your batteries in the mod. The USB port on mods is usually just there as a method of updating the firmware, and often doesn’t have the proper charging circuits required to charge your batteries safely and maintain battery health. Not to mention, with the 0.5A of current that most USB ports are rated for, you’d be waiting a long time!

Batteries in a battery charger

Instead, it is highly recommended that you use an external battery charger, and at that one that has plenty of safety features. They come in all shapes and sizes, with the ability to charge 1, 2, 4, and even 8 or more batteries at once! Some will even charge batteries of different sizes and specifications simultaneously without missing a beat. Aside from this clear advantage, they are often much quicker to charge your batteries to full capacity, and often include some diagnostic features that can tell you if something is wrong with any of your cells. Check out the Nitecore Battery Charger range on our webshop, which includes the i8 featured above.

Battery Wraps
If you look closely at a vape battery, you will see that is shrink wrapped in plastic. This is because, contrary to popular belief, the negative terminal of the battery is not just on the bottom, but extends all the way up the sides of the battery too. So in order to keep everything safe and free of short-circuits the batteries are wrapped in plastic, with the only opening for the negative terminal at the bottom. Also included is an isolator ring, which keeps the negative sides away from the positive top by sitting just around the top of the battery.


Problems arise when, due to wear and tear, the plastic wrap gets ripped, torn, sliced, or rubbed away. This opens up more of the negative terminal on the sides to the inside of your mod, and increases the potential for short circuits. Additionally, black marks can appear due to heat interactions with the wrap and the side of the battery.

ODB Battery Wraps

Luckily, this is really easy to fix. While you can patch your batteries with insulating electrical tape, this may lead to your batteries not being able to fit into your mod due to the extra material. The recommended fix is simply to re-wrap the battery entirely! There are plenty of reasonably priced third-party wraps available on the market, many of which feature custom printed designs, and the only tool you need to apply them is a hair dryer. Just don’t lose that isolator ring when you take the old wrap off! Our recommendation is the always excellent ODB Wraps: They're easy to apply and they look fantastic.

Mech mods, batteries, and you

Mech mods, batteries, and you
So far the information we’ve given is relatively tame, so now it’s time to take a real deep dive into all of your batteries specifications, and why you really need to know these before thinking about using a mech mod.

Before we mentioned that you may find 18650s in laptop batteries, attached to some safety and charging circuits. These are important as they help the device monitor the charge level, temperature, and general health of the cells inside.

While a regulated vape mod does include these features, a mech mod does not. Therefore it is vital that you understand your batteries’ limits. In particular, you need to pay attention to the Maximum Continuous Discharge Current/Rate, which is measured in Amps (A). This figure tells you just how much current your battery can safely supply, and needs to be taken into account when doing your ohm's law calculations.

Check the Maximum Continuous Discharge rating

If you're considering using a mech mod, carve this warning into your memory: never, EVER exceed this rating! Ideally, you shouldn’t really be getting too close to the maximum rating, you should leave some headroom to make sure you’re well within the safety limit. Exceeding this limit can cause instant battery failure, sometimes in violent, spectacular manner.

Also, be careful not to confuse the Maximum Continuous discharge with the Maximum Pulse discharge. This figure will be higher, but generally should be ignored when it comes to vaping. Any firing of your vape, regardless of how long it is firing, is considered a continuous discharge. Don’t go pushing the limits, it’s just not worth it!

Black spots on the negative terminal of a battery

One last thing to keep your eye out for when using mech mods is black spots on the negative terminal. This occurs when the mechanical switch makes contact with the battery, and each time a small spark will leap from the battery to the contact. This will slowly leave marks and potentially damage the battery. To avoid this, rotate which batteries you’re using each time they’re fully discharged to spread out the wear.



That’s just about wraps things up for our blog on Batteries and Battery Safety! If you still feel like you have some questions, or if you want some advice on whether your batteries are safe to use, you can pop into one of our retail locations and speak to a member of staff. They’ll be more than happy to help you!

All of the products we discussed in this blog are available to purchase from our Leicester, Hamilton, and Loughborough stores, as well as our online webshop!

Until next time, stay Flawless!

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