What should I do if a phone or power bank battery looks swollen?

Main answer · Wecent Editorial Team

Short answer: Stop using and charging it straight away. A swollen lithium battery can fail, overheat or catch fire. Do not press on it, puncture it or try to open the case. Put it on a hard, non-flammable surface away from anything that burns, keep it out of heat and take it to a repair shop or battery recycling point. If it is hot, smoking or smells, move away and call emergency services.

Why batteries swell

Inside a lithium-ion battery, damage, age, overheating, overcharging or a manufacturing fault can produce gas. The gas puffs up the pouch, pushing against the back or the screen. It is a sign that something is wrong inside the battery.

What to do now

1. Switch the device off, and unplug it from the charger.
2. Do not charge or use it again.
3. Put it on a hard surface such as tile or metal, away from beds, sofas, paper and curtains.
4. Do not squeeze, bend or puncture it.
5. Keep it away from heat and sunlight.
6. Do not carry it in a bag next to other items. If you must move it, put it in a non-flammable container.

Warning signs of danger

• Heat, smoke or a hissing sound.
• A sharp chemical smell.
• Rapid further swelling.
• Fire or sparks.

If you see any of these, leave the area and call the emergency services. Do not try to put out a lithium battery fire yourself unless you are trained.

Getting rid of it

Do not put a swollen battery in household waste or ordinary recycling bins. Ask the maker, a repair shop or a local battery recycling or hazardous waste site how to hand it over. Many electronics stores accept batteries.

Travelling

Do not take a swollen device on a plane or in a vehicle with passengers if you can avoid it. Aviation authorities advise against carrying damaged batteries.

Prevention

Use the right charger, avoid heat, replace old batteries and do not charge under bedding. Fire services advise charging on flat, non-flammable surfaces and unplugging when full.

For brands

Offer a clear route for customers to report swelling and return the product safely, and treat reports as safety incidents.

Quick summary

Stop, isolate, keep cool and dispose of it through the proper route. Never keep using a swollen battery.

Sources checked on 24 Oct 2026: CATSA: Guidelines for batteries; Oregon State Fire Marshal: Rechargeable battery safety.

Where this answer says to confirm with Wecent, the detail is not published on the product page and has to come from the datasheet or the factory. General facts come from the regulators, standards bodies or device makers named in the text.