Battery Safety
Vape batteries are powerful lithium-ion cells that require careful handling. Follow this guide to stay safe and get the most from your batteries.
Vape batteries are not ordinary batteries
If you own a regulated vape mod powered by external batteries such as 18650s or 20700s, this guide is essential reading.
Handle with care
Vape batteries are not like your TV remote AAs or AAAs. They are high-drain lithium-ion cells with far greater power density. Mishandling them can result in venting, fire, or explosion. Use special caution when charging, discharging, and storing rechargeable Li-Ion 18650 cells.
High Power Cells
18650, 20700, and 21700 cells deliver high continuous discharge rates. They must only be used in devices they are rated for.
Know Your Specs
Always check the amp limit (CDR) of your battery against the power demands of your device and coil resistance before vaping.
Buy from Reputable Sources
Always purchase batteries from a trusted retailer. Counterfeit and rewrapped cells are common and can be extremely dangerous.
Caring for your batteries
Proper care extends the life of your batteries and significantly reduces the risk of accidents.
Inspect battery wraps regularly
Always keep the protective wrap on your battery in pristine condition. If you notice a nick, tear, or puncture on the wrap, re-wrap it immediately before use. Battery wraps are inexpensive and easy to replace — your local vape shop will often do it for free.
Check for damage & denting
Regularly inspect your batteries for any physical damage, denting, or swelling. Do not use a damaged battery under any circumstances. A dented or swollen cell should be safely disposed of at a battery recycling point.
Insert batteries correctly
Always ensure batteries are inserted the correct way around to match the positive (+) and negative (−) terminals in your device. Even if your mod has reverse polarity protection, incorrect insertion can still cause damage or a short circuit.
Keep away from extreme temperatures
The chemicals inside lithium-ion batteries should never be exposed to extreme heat or cold. Store at room temperature and never leave batteries in a car on a hot day or near a heat source. Keep well away from fire at all times.
Use battery cases
Never carry loose batteries in your pockets or bags. An unprotected battery can short circuit against metal objects and vent dangerously.
Always use a battery case
Invest in a cheap plastic battery case for transporting and storing batteries when not in use. This prevents batteries from touching each other or coming into contact with metal objects like keys and coins — which can cause a short circuit, venting, and in extreme cases, an explosion.
Do: Use a battery case
Keep spare batteries in a dedicated plastic hard case. Most battery cases cost under £2 and can prevent serious accidents.
Don’t: Use torn wraps
A damaged battery wrap removes the insulation between the cell and metal surfaces. Never use a battery with a torn or nicked wrap.
Don’t: Pocket loose batteries
Loose batteries in pockets or bags can touch coins, keys, or each other. This causes a short circuit which can result in the battery venting or exploding.
Use the right batteries for your device
Not all batteries are suitable for vaping. Using the wrong cell for your mod or coil resistance can be extremely dangerous.
Some batteries are optimised for low-wattage MTL vaping, others are rated for high-drain sub-ohm use, and some are simply not suitable for vaping at all. When selecting batteries, always check the manufacturer’s Continuous Discharge Rating (CDR) — not just the numbers printed on the wrap, which are often misleading or exaggerated.
Stick to well-known, trusted brands such as Samsung, Sony, LG, and Molicel. Avoid unbranded or suspiciously cheap cells, which are frequently counterfeit rewraps with inflated specs.
Married batteries
If your device uses two or more batteries, always use a matched pair from the same brand and batch. “Marrying” batteries — keeping the same cells together — ensures they discharge evenly and reduces the risk of imbalance and venting.
Trusted brands
Samsung, Sony, LG, Molicel, and Efest are well-regarded battery brands with verified specs and real CDR ratings.
Check your coil’s amp draw
Divide your wattage by your voltage (approx. 4.2V for a full cell) to estimate amp draw. Your battery’s CDR must exceed this figure.
Don’t leave batteries charging unattended
Charging is the highest-risk activity with lithium-ion batteries. Never charge overnight or leave batteries unsupervised.
Never charge overnight
Although rare, battery charger failures do happen. Never leave batteries charging while you are asleep or away from home. The risk of fire from an unattended charge is real and preventable.
Remove batteries when fully charged
Check regularly while charging. As soon as the charge is complete, remove the batteries from the charger immediately to prevent overcharging, which degrades cell performance and can lead to battery failure over time.
Charge on a fireproof surface
Always charge batteries on a hard, non-flammable surface such as a ceramic tile or concrete floor — never on a carpet, sofa, or bed. A dedicated LiPo safe charging bag adds an extra layer of protection.
Use a quality dedicated charger
Always charge with a quality dedicated battery charger rather than relying solely on your mod’s USB charging port. A good charger monitors each cell individually and prevents overcharge. Recommended brands include Nitecore, Xtar, and Efest.
When to replace your batteries
Batteries degrade over time. Knowing when to replace them keeps you safe and ensures consistent performance.
Torn or damaged wrap
Replace the wrap immediately, or if the cell itself is damaged, retire the battery. Never use a battery with exposed metal underneath the wrap.
Swelling or venting
A swollen or bulging battery is venting gas and is extremely dangerous. Do not charge or use it. Allow it to cool in a safe, open area before taking to a battery recycling point.
Reduced runtime
If your battery drains significantly faster than it used to, the cell has degraded and should be replaced. Typical 18650 lifespan is 300–500 charge cycles.
Physical denting
Any dent in a battery cell is cause for immediate retirement. Dented cells have compromised internal structure and present a short-circuit risk.
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