The battery in your Galaxy has produced gas inside a sealed pouch, and the gas has nowhere to go, so the pouch has grown. That is what lifts a screen at the corner, pushes the back glass away from the frame, or makes the phone rock when you set it down flat.
Swelling does not reverse. No setting undoes it and there is no safe way to let the gas out. The cell has to come out of the phone.
You do have time to deal with this properly. A swollen cell is a fire risk rather than a fire, and the risk climbs the longer it stays in the phone and the more it gets charged, squeezed or knocked. Three things apply from now until it is fixed. Do not charge it. Do not press the screen or the back cover flat again. Do not put anything sharp near it, which includes trying to prise the phone open yourself.
The check that takes thirty seconds
Take the case off first, because a case hides the shape of the phone.
Put the phone face up on a hard flat surface, a table or a kitchen counter, and nudge one corner. If it rocks like a wobbly restaurant table, or spins when you push it, the phone is no longer flat, and a battery is the usual reason.
Then hold the phone at eye level against a light and look along the seam where the screen meets the frame, and along the edge of the back cover. A swollen cell opens those seams from the inside, so what you are looking for is a hairline gap that runs along one side and closes off at the ends.
Two other signs. A snap-on case that used to click on and now will not, or that feels tight going on. Side and volume buttons that have gone stiff or stopped clicking properly.
If you get a faint sweet or metallic smell off the phone, the pouch has already opened. Stop there and stop using it.
What to do before you pay anyone
Unplug it and switch it off. Charging puts more energy into a cell whose chemistry is already unstable, and it makes heat, which is one of the things that caused this.
Take the case off and leave it off. A tight case holds pressure against the cell.
Put the phone somewhere open and hard. A tiled floor, a plate on a counter, an empty metal tin. Not a pocket, not a bed, not a drawer packed with paper, and not the boot of a car standing in the sun.
If the phone still switches on, back it up now, then switch it off again and leave it off. That is the one good reason to turn it back on.
While it is on, get the model number down. Open Settings and tap About phone. The model number, serial number and IMEI are on that screen. That number is what a repairer uses to check the right battery, so having it saves working it out at the counter.
And if the phone is still inside its Samsung warranty, check with Samsung first. That route may cost you nothing, and it is the sensible one to try before you pay anybody, us included.
If the phone lies flat and nothing lifts, this is probably wear rather than swelling
A worn battery holds less charge and drops faster, but it keeps its shape. That is a different problem with a cheaper answer, and some of it is free.
Start with the check Samsung documents. Open the Samsung Members app and find Diagnostics. In current versions of the app it sits under the Get help tab. Run the battery test, or tap Test all to run everything. The result is a word rather than a number. Normal means no performance issue with the battery. Weak means efficiency may have dropped through long term use or the conditions the phone has lived in. Bad means the battery life has significantly degraded, and Samsung’s own advice on a Bad result is to visit a Samsung support centre.
Samsung does not give every Galaxy a battery health percentage. Some newer models, from the Galaxy S25 series on One UI 7 onwards, also show a battery information screen with a maximum capacity figure and a charge cycle count, but that screen is not on every phone and not in every country. If it is missing from your Settings, that is the software, not a fault.
Next, rule out an app. Switch the phone off. Switch it back on, and when the Samsung logo appears, press and hold the Volume down key until the phone has finished starting. Safe mode shows in the bottom left corner. To leave safe mode, restart the phone. Safe mode loads none of the apps you installed, so if the phone lasts the day in safe mode and dies by lunchtime out of it, something you installed is draining it and no new battery will fix that.
Then slow the wear down. Open Settings, tap Battery, then tap Battery protection. On One UI 6.1 there are three settings. Basic stops charging at 100 per cent and starts again at 95 per cent. Adaptive uses Maximum overnight and Basic before you wake. Maximum stops charging at 80 per cent. On One UI 7 and later you set the Maximum limit yourself rather than being held at 80 per cent. On versions older than One UI 6.1 there is one setting only, which caps charging at 85 per cent. The Battery screen has been rearranged more than once, so if Battery protection is not where you expect it, open Settings and search for it.
Why a cell swells, and why pressing it back is the dangerous part
A lithium ion battery is a sealed pouch holding a liquid electrolyte. Over enough charge cycles and enough heat, that electrolyte breaks down and gives off gas. The pouch is sealed, so the gas stays where it is and the pouch gets thicker. Everything you are looking at is the consequence of a slightly thicker pouch inside a phone that has no spare room in it.
Four things drive it. Age, because the chemistry degrades over hundreds of cycles. Heat, because heat speeds up every reaction inside the cell. Long spells sitting at 100 per cent on a charger. And physical damage, because a knock hard enough to deform the inside of the cell can start it swelling early.
Heat is the one people here control least and cause most. A phone on a dashboard, a phone charging on a bed under a duvet, a phone left in a parked car through a Durban afternoon. Humidity on its own does not swell a battery, but the heat that comes with it does.
A swollen pouch does not usually tear open by itself, and that is the whole reason for the warnings. What turns a swollen cell into a fire is a puncture or a hard crush, because that lets the layers inside touch where they should not. Pressing a lifted screen back down is a crush. Levering a back cover off with a knife or a screwdriver is a puncture. On a current Galaxy the battery sits behind a glued back cover and is held down with adhesive, so it is not a pack you pop out, and working at it blind is how people get hurt.
The repair that fixes it
A battery replacement. The swollen cell comes out, an original Samsung battery goes in, and the phone is sealed back up. The current price for your model is on the battery replacement page.
Two things can add to that, and you can see both before you decide anything.
If the swelling has already lifted or cracked the back glass, the back cover gets replaced along with the battery, because a panel that has been pushed off will not reseal. Those prices are on the back cover replacement page.
If the cell pushed hard enough against the display to leave a bright patch, a dark blot, a line, or an area where touch has stopped responding, the screen is damaged and a new battery will not bring it back. Screen prices are on the screen replacement page. If you would rather see every model and every repair in one place, they are all on the Samsung repair prices page.
On the work itself. We fit original Samsung parts. The price shown includes the part and the fitting. Most jobs are finished in three working days. The part and the work carry a three month warranty.
When it is not worth repairing
Sometimes the sums go against the phone.
One case is damage that has stacked up. A battery on its own is one price. A battery and a back cover is another. A battery, a back cover and a screen the swelling has ruined is a third. Look up all three prices for your exact model, then check what yours is selling for second hand, and put those two numbers next to each other. We are not going to guess your phone’s value for you and nobody else should either.
The other case is age. If the phone has stopped getting Samsung software updates, you are putting money into something already on its way out, and a swollen cell is a fair indication of how much life the hardware has left in it.
What does not follow from either case is keeping the phone and living with it. A swollen battery is not a cosmetic fault you carry for another year. If the sums say replace the phone, replace the phone, and then deal with the old one properly. Do not drop it in a household bin with a swollen cell inside it. Take it to an e-waste collection point.
Getting it to us, and why it cannot be posted
Do not post it and do not put it in a suitcase. Damaged and swollen lithium batteries are prohibited from passenger aircraft under the international air transport rules, in the cabin and in the hold, and couriers that move anything by air work off the same list.
That suits how we work anyway. Everything is done on site at Unit B, 31 Solstice Road, Umhlanga Ridge, so there is no courier and no mail-in option and the phone is brought in to us. We have been at it since 2007.
People come to us from across Durban and the wider area, up the north coast and down the south coast, from inland, and a fair number drive down from Gauteng. Phone 031 569 2806 or WhatsApp 084 044 3444.
Common questions
Is it safe to keep using my Samsung until I can get it in?
No. Switch it off, take the case off, and leave it unplugged. Charging puts more energy and more heat into a cell that is already unstable, and a snap-on case holds pressure against it. If you need something off the phone, switch it on once, back it up, and switch it off again. Most jobs at our Umhlanga counter are finished in three working days, so it does not have to sit switched off for long, but it should stay off until it is opened up.
Can I fly with a swollen phone battery, or courier it to a repair shop?
No to both. Damaged and swollen lithium batteries are prohibited from passenger aircraft under the international air transport rules, in the cabin and in the hold, and couriers moving freight by air follow the same list. If a device gets hot or starts smoking at an airport or on board, tell the crew or airport staff rather than handling it yourself. It makes no difference to getting the repair done here, because we work on site at Unit B, 31 Solstice Road, Umhlanga Ridge and the phone is brought in rather than posted.
Will Samsung replace a swollen battery for free?
If the phone is still inside its Samsung warranty, check with Samsung first, because that route may cost you nothing. Outside it, a battery replacement is a paid job wherever you take it. We fit original Samsung batteries, the price includes the part and the fitting, and the part and the work carry a three month warranty. The current price for your model is on the [battery replacement page](https://onnuritech.co.za/repairs/battery-replacement/).
Can the Samsung Members battery test tell me whether my battery is swollen?
It will not tell you that. Open the Samsung Members app and find Diagnostics, which in current versions of the app sits under the Get help tab, then run the battery test. It reports the battery as Normal, Weak or Bad rather than a percentage, and Samsung does not document it as a check for physical swelling. Use it to judge a worn battery. For swelling, take the case off and put the phone on a flat table to see whether it still lies flat.
The back cover on my Galaxy S22 is lifting at one corner. Is that the battery?
On a sealed Galaxy that has not been dropped hard or opened before, a back cover separating from the frame is usually a battery pushing it off from the inside. Do not press it back down and do not tape it shut, because squeezing a swollen cell is the thing every warning is about. Once the back glass has been pushed off the seal has gone, so that panel is normally replaced along with the battery. Both prices sit on the [battery replacement page](https://onnuritech.co.za/repairs/battery-replacement/) and the [back cover replacement page](https://onnuritech.co.za/repairs/back-cover-replacement/).
Will Battery protection stop this happening to my next battery?
It cuts the time the cell spends sitting full, which is one of the things that ages it. Open Settings, tap Battery, then tap Battery protection. On One UI 6.1 there are three settings. Basic stops charging at 100 per cent and starts again at 95 per cent. Adaptive uses Maximum overnight and Basic before you wake. Maximum stops charging at 80 per cent. On One UI 7 and later you set the Maximum limit yourself. On versions older than One UI 6.1 there is one setting only, which caps charging at 85 per cent. If the Battery screen on your version does not show it, open Settings and search for battery protection. Heat matters as much as charge level, so keep the phone off dashboards and out of parked cars. None of it is a guarantee against swelling.
