Cool, dry and contained: that is the whole idea. Heat ages lithium cells and loose metal can short them, so the hot car and the coin pocket are the two places your vape and spare batteries should never live.
The short version
- Room temperature is ideal. A parked car in summer sun is one of the worst places.
- Spare cells always go in a plastic case, never loose with keys or coins.
- For storage longer than a few weeks, leave cells about half charged.
- Do not store devices flat for months. Check and top up now and then.
Heat is the real enemy
Lithium-ion batteries age faster the hotter they are kept, even when they are switched off. Leave a vape on a sunny dashboard all summer and the battery will lose capacity far quicker than one kept in a drawer, and very high temperatures put real stress on the cell.
A car parked in direct sun can get far hotter inside than the air outside, enough to make a dashboard painful to touch. That is no place for any lithium battery, and e-liquid in the pod will thin out and leak too.
Most cell datasheets list charging between roughly 0°C and 45°C. Normal room temperature sits comfortably in the middle, which is exactly where you want your kit.
- 0°CDo not charge below this
- 20°CRoom temperature
- 45°CTypical charging limit
- 60°CHot car, summer sun
Pockets, keys and coins
A spare cell loose in a pocket with keys or coins is the most common way people short a battery. Metal touches the positive button and the negative can at the same time, and with nothing to limit the current the cell heats up fast.
The fix costs a couple of pounds: a plastic battery case. Most hold two cells and click shut. Your mod or pod kit is fine in a pocket on its own, but lock it or switch it off if it has a fire button, so nothing presses it in a bag.
The checklist below covers the places to avoid. If any of them describe where your spare cell is right now, sort it today.
Putting kit away for a while
Going back to a pod kit for a few weeks? Taking the mod on holiday and leaving the spare cells at home? Long storage is where a little preparation pays off.
Lithium cells are happiest stored at around half charge, roughly 3.7 to 3.8V. A full cell kept hot ages faster, and a flat cell can slowly drain below the point where it can be safely recharged. Most chargers with a screen show voltage, which makes hitting half easy.
Store removable cells out of the mod, in a case, somewhere cool and dry. Then put a reminder in your phone to check them every couple of months.
- Charge to about halfAim for roughly 3.7 to 3.8V, or around half on a battery indicator.
- Take cells out of the modRemovable cells come out. Lock or switch off devices with built-in batteries.
- Case themPut the cells in a plastic battery case.
- Pick a cool, dry spotA cupboard at room temperature, away from sun, radiators and damp.
- Check every couple of monthsTop up to about half if the voltage has dropped noticeably.
Cars, bags, beaches and lockers
Day-to-day life throws up its own storage problems. The car is the big one: take your vape with you when you park, because the glovebox and cup holder heat up too. In winter the opposite applies, and a freezing car will leave your kit sluggish until it warms up, which is covered in our guide to vaping in hot and cold weather.
On a beach or at a festival, keep it in the shade in a bag rather than on a towel in full sun. Gym lockers are fine, as long as spare cells are cased and the device is locked.
Tap the one that applies to you.
Where does your vape spend its time?
Take it with you. Parked cars in sun get far hotter than outside, which ages the battery and makes pods leak.
Keep the bag in the shade and the vape inside it, not on the towel in direct sun.
Fine. Lock the device and keep any spare cells in a case.
Fine, ideally an inside pocket on its own, away from keys and coins.
The drawer of old kit
Most vapers have one: a drawer of old pod kits, half-used coils, empty bottles and a couple of disposables from before the UK single-use vape ban came into force in June 2025. Old devices with batteries in them should not sit there forever, because cells left flat for months degrade and damaged ones are better out of the house.
Take dead devices and old cells to a recycling point rather than the bin. Our guide to disposing of vapes and batteries explains where.
While you are at it, check where the e-liquid lives. Bottles belong somewhere cool, dark and out of reach of children and pets, which our e-liquid safety guide covers.
You are putting your spare 18650s away for three months. What charge level should they be at?
Quick answers
Can I leave my vape in the car?
Not in warm or sunny weather. Parked cars get far hotter than the air outside, which ages the battery and makes pods leak. Take it with you.
How should I store spare vape batteries?
In a plastic battery case, somewhere cool and dry, never loose with keys or coins.
What charge should I store batteries at?
Around half, roughly 3.7 to 3.8V, for anything longer than a few weeks. Check them every couple of months.
Is it OK to keep a vape in my pocket?
Yes, on its own. Lock it if it has a fire button, and never put spare cells in a pocket without a case.
