The Ultimate Beginners Guide To Vape Batteries

What are Vape Batteries?

Made from Lithium-Ion, vape batteries supply power to heat up e-liquids and produce flavourful vapour, making them an essential component in any vaping device. Unless you own a vape pen or starter kit that includes built-in batteries, it’s vital to ensure that you are using the correct external batteries for optimum performance as well as safety.

Rechargeable and removable, external batteries function similarly to those found in common household appliances, and while larger in size, the scientific principles stay the same. When a battery is activated, the chemicals inside act to produce energy which is then converted to power, or heat in terms of a vape kit. Both internal and external vape batteries function by activating a vaping device’s firing button. This passes energy, or voltage to the coil in your tank, where current is then drawn from the vape battery to heat it and produce tasty vapour.

The most common external batteries for vaping devices include 18650, 20700 and 21700. They are named as such due to their width and height. As an example, the most commonly used vape battery size, 18650, is 18mm in diameter and 65mm in height. It’s important to note that the larger the battery, the higher the output and capacity will be.

• 18650 batteries are considered to be the most popular choice of removable battery due to their versatile power and output advantages for both small and large vaping devices.
• 20700 batteries are larger in comparison to 18650s, and are able to support higher power outputs for longer, such as what is required with sub ohm devices. They’re also available to use in either single or dual 20700 batteries.
• 21700 models are the largest vape batteries, offering enhanced power and capacity. These batteries support sub ohm and high wattage vaping.

External batteries haven’t always been around for vaping - they were introduced as a convenient solution to allow vapers to quickly replace drained batteries without having to wait for them to recharge.

What is Ohm’s Law?

In simple terms, Ohm’s Law is the relationship between voltage, current and resistance. Vapers who use customised coils will utilize this handy formula to understand how much power their coil consumes, and whether or not it is safely compatible with their device’s battery.

Mouth to Lung (MTL) Vaping Devices

As mouth to lung devices have a higher resistance of 1.0 Ohm or above, they produce less vapour, boost e-liquid flavour, and can even offer long-lasting battery life. When vaping with a mouth to lung device, we recommend always using a lower Amp output battery. 

The Do's and Don'ts for Vaping Battery Safety

Understanding how to power your device safely and effectively is a number one priority when it comes to vaping. While most battery chargers and vaping devices will have short circuit and over charge protection, you should still keep the following battery safety tips in mind at all times:

• Do not use phone chargers to power your vaping device. We recommend charging using a 1/2a output plug.
• Always store external 18650 batteries in a battery box and avoid placing them loose in pockets.
• Avoid leaving your batteries unattended while charging.
• Always turn your vape off when placing it into compartments such as pockets or bags.
• Never expose your battery to extreme hot or cold temperatures.
• Always replace batteries that are showing signs of damage or degradation.
• Keep loose batteries away from conductive materials such as coins or keys.

Advanced Tips for Choosing the Right Vape Battery for Your Needs

Once you’ve mastered the basics of volts, amps, ohms, and mAh ratings, you can start to fine-tune your battery choices for a more personalised vaping experience. Whether you’re a casual mouth-to-lung vaper who enjoys nicotine salts at low wattages or a cloud chaser using high-VG vape juice in a sub-ohm pod mod, the right battery can make a big difference in performance.

Match Battery Output to Your Vaping Style

For MTL devices and nicotine salt e-liquids: Look for a battery with a moderate continuous discharge rate (10–15A) and higher capacity (2,500mAh+). This will maximise battery life between charges, ideal for steady, all-day vaping.

For sub-ohm cloud production: Choose a battery with a high continuous discharge rate (20–30A) to handle the demands of low-resistance coils. While the capacity may be slightly lower, you’ll benefit from faster ramp-up times and denser vapour clouds.

For pod mod kits: Many modern pod mods use either integrated batteries or single-cell external batteries. Check your kit’s requirements and choose a cell that balances capacity and output to match your preferred wattage range.

 

Understanding Continuous vs. Pulse Discharge Ratings 

Battery safety and performance often come down to understanding discharge ratings. Manufacturers may list both continuous and pulse discharge rates, but it’s the continuous rating that matters most for safe, sustained vaping. Continuous discharge is the maximum current the battery can safely deliver until it is fully depleted. Pulse ratings are higher but are only safe for very short bursts — pushing your battery to pulse limits regularly can cause overheating and shorten lifespan.

Pro tip: Always select a battery based on its continuous discharge rating to ensure both safety and reliable performance.

 

How Battery Chemistry Affects Performance

Not all lithium-ion vape batteries are created equal. Internal chemical composition plays a role in how the battery behaves under load. IMR (Lithium Manganese Oxide) – Favoured for high-drain applications like sub-ohm vaping due to their stability and safety profile.

INR (Lithium Nickel Manganese Cobalt Oxide) – Offers a balance of capacity and discharge rate, making them versatile for both MTL and DTL devices.

ICR (Lithium Cobalt Oxide) – High capacity but generally lower discharge rates, less common for high-power vaping.

 

Battery Pairing in Dual or Triple Battery Mods

If your vape mod uses more than one battery, always “marry” your batteries. This means:
Buying them at the same time.

Charging and discharging them together.

Keeping them in the same positions within the device.

Mismatched batteries can discharge unevenly, placing strain on both the cells and the device, potentially leading to failure.

 

Charging Tips for Maximum Longevity

While we’ve already covered the benefits of using an external charger, here are a few extra tips to keep your vape batteries healthier for longer:

Charge before fully draining – Lithium-ion batteries prefer partial cycles rather than complete discharges.

Avoid cheap USB wall plugs – Always use certified chargers with appropriate current ratings.

Don’t charge immediately after heavy use – Let the battery cool for 15–30 minutes before charging to prevent heat-related degradation.

 

Signs Your Vape Battery Needs Replacing

Even the best-maintained batteries will eventually lose performance. Replace your battery if you notice:

1. A significant drop in capacity (needing to recharge far more often).
2. Overheating during normal use.
3. Physical swelling, dents, or corrosion.
4. Voltage dropping quickly after a full charge.

For integrated battery vape kits, this means replacing the entire device once performance drops noticeably.

 

Travelling and Vaping — Battery Safety on the Go

If you take your vape kit on holiday or work trips, battery safety should be a top priority. Airlines require spare lithium-ion batteries to be carried in your hand luggage, not checked baggage. Always use protective cases for spare cells, and never store them loose with metallic items. If visiting hot climates, keep your kit and batteries in shaded areas to prevent overheating.

 

Environmental Impact — Recycling Vape Batteries

Throwing vape batteries in the bin is both unsafe and environmentally damaging so instead its advisable;

• Use local battery recycling bins at supermarkets or vape shops.
• Check your council’s hazardous waste disposal services.
• Support brands and shops that offer battery take-back programs.
• Recycling recovers valuable materials like nickel and cobalt, reducing the need for destructive mining and keeping hazardous waste out of landfill.