You pick up your phone and something feels off. The screen is lifting at the edge, the back cover has a small gap, or the phone rocks on the table when you tap it. It's easy to shrug that off, but it's one of the classic signs of a swollen battery, and it's not something to leave for another week. Here's what's going on, what to do straight away and how to get it sorted safely.
What is a swollen battery?
Phone batteries are lithium-ion. Over time, or after damage, the inside of the battery can start producing gas. That gas has nowhere to go, so the battery puffs up like a small pillow and pushes against everything around it.
It isn't just a phone problem either. Tablets, laptops, power banks and wireless earbuds can all suffer from the same issue.
Is a swollen battery dangerous?
It can be. A swollen battery is under pressure, which makes it more likely to overheat, leak or, in rare cases, catch fire. Most don't end that badly, but it's not a risk worth taking with something you carry in your pocket. Treat it as urgent.
Warning signs to look out for
| What you notice | What it usually means |
|---|---|
| Screen lifting at the edges | The battery is pushing the display out of the frame |
| Gap in the back cover or case | The battery has expanded and there's no room left |
| Phone wobbles on a flat surface | The back is bulging |
| Case suddenly doesn't fit | The phone body has changed shape |
| Fast battery drain or unusual heat | The battery is failing internally |
| Stiff or unclickable trackpad (MacBook) | The laptop battery is swelling underneath |
What causes it?
- Age: batteries wear out after lots of charge cycles.
- Cheap chargers: non-certified chargers can overcharge or overheat the battery.
- Heat: hot cars, direct sun and charging under a pillow all add up.
- Damage: drops, bends and crushing can harm the cells inside.
- Poor-quality replacements: a low-grade battery from a previous repair can swell early.
What to do straight away
- Stop charging it. Unplug it now.
- Switch it off and stop using it if you can.
- Keep it somewhere safe. A hard surface like a worktop or tiled floor is better than a bed or sofa, and keep it away from heat and anything flammable.
- Don't press, pierce or flatten it. This is the most dangerous thing you can do.
- Don't open the phone yourself. A damaged battery can react badly if it's handled the wrong way.
- Get it checked soon. Don't wait until it gets worse.
What not to do
- Don't keep charging it just to get through the day.
- Don't carry it in your pocket or bag while it's swollen.
- Don't take it on a plane.
- Don't put it in your normal household bin. Old batteries need to be disposed of properly.
How is it fixed?
A swollen battery can't be repaired, it has to be replaced. A technician will remove the old one safely, fit a new one and check that the swelling hasn't damaged anything else. That last part matters more than people think. A swollen battery can push the screen out of place or crack it, so a proper check is worth more than a quick swap. If the display did get damaged, our screen repair options can sort that in the same visit.
Battery replacements are usually quick, and in most cases your phone can be ready on the same day.
Can I post it for repair?
Be careful with this one. Damaged batteries have special rules for postage, and couriers don't always accept them. Please give us a call first and we'll tell you the safest way to get it to us. If you're local, dropping it in person is always the simpler option.
How to stop it happening again
- Use original or good-quality certified chargers.
- Avoid charging under pillows, blankets or on soft furniture.
- Don't leave your phone in a hot car or in direct sunlight.
- Replace the battery when its health drops to around 80% or lower.
- Get the phone checked after a hard drop or if it has been bent.
What happens when you bring it to FonePro
Book online or walk into one of our stores in Rotherham, Middlesbrough or Darlington. We'll check the battery, tell you honestly what needs replacing and give you a clear quote before we start any work.
Every repair comes with our 90-day warranty covering parts and labour, and our no fix, no fee guarantee means you're never charged for a repair that doesn't work. You can see what other customers say on our reviews page.
Think your battery might be swollen? Book a free diagnostic and we'll take a look. No pressure, no upselling.
Frequently asked questions
Can I keep using my phone with a swollen battery?
It's best not to. Switch it off and get it checked as soon as you can.
Will a swollen battery go back to normal?
No. Once a battery has swollen, the only safe fix is a replacement.
How much does a battery replacement cost?
It depends on your model. Contact your nearest FonePro store for a quick quote.
Is a swollen battery covered by warranty?
It might be if your phone is still within its manufacturer's or seller's warranty, so it's worth checking before you book a repair.
Can laptops and tablets get swollen batteries too?
Yes. On MacBooks and other laptops, a swollen battery can push the trackpad and case out of shape. Our technicians repair phones, tablets and laptops.
Do I need an appointment?
Not for most repairs. You can walk in, or book online to save time.