Glossary › Laptop Repair › Swollen Battery
What is a Swollen Battery?
A swollen battery is a lithium battery that has puffed up because gas has built up inside its cells. In a laptop it pushes on everything around it, and it is a fire risk that should be dealt with straight away.
How to recognise it
The trackpad becomes hard to click or sits proud of the case. The laptop rocks on a flat desk. The bottom cover bulges or a seam opens along the edge. Keys in the middle of the keyboard may feel raised. On some laptops the first sign is simply that the lid no longer closes flush.
Why it happens
As lithium cells age, the chemicals inside break down and release gas. Heat speeds this up, and so does keeping a battery full for years, physical damage, or a poor quality replacement. A high cycle count makes it more likely, but it can happen to a lightly used battery that has spent its life hot.
What to do
Stop charging the laptop and switch it off. Do not press on the bulge, and never puncture the battery. Keep it away from anything flammable and bring it in for the battery to be removed. Do not put a swollen battery in the household rubbish. It needs proper battery disposal.
What happens if you leave it
The swelling keeps growing. It cracks the trackpad, bends the case and can press on the motherboard, turning a battery replacement into a much larger repair. In the worst case a damaged cell can catch fire.
Related terms
Battery Cycle CountDC JackLiquid Damage