Swollen Phone Battery: What to Do Right Now and How to Fix It

If your phone battery is swollen, stop charging the phone, power it down, and move it away from anything flammable. A swollen lithium-ion battery cannot be fixed or “deflated”. It has to be replaced, and the old cell has to be handled and recycled with care. This guide covers how to confirm the problem, what to do in the first ten minutes, what to do if the phone gets hot or smokes, how replacement works, and how to keep the next battery from swelling.

TL;DR

• A swollen or bulging battery is damaged. Stop charging and stop using the phone, then power it off.
• Signs include a lifted back cover, a screen pushing up from the frame, a phone that rocks on a table, heat, odd smells and charging that behaves strangely.
• There is no way to unswell a battery. The only fix is a correct replacement, and never puncture or squeeze the cell.
• If the phone is smoking, hissing or on fire, leave the area and call emergency services. Do not try to put it out yourself.
• Never throw a swollen battery in household trash or curbside recycling. Take it to a designated battery or e-waste drop-off.

Table of Contents

• How to tell if a phone battery is swollen
• Is it safe to keep using a phone with a swollen battery?
• What to do right now
• If the phone is hot, smoking or leaking
• Why phone batteries swell
• Can you unswell a battery?
• Our perspective
• Get the right replacement battery and tools
• How to store, transport and dispose of a swollen battery
• How to keep the next battery from swelling
• FAQ
• Sources

How to tell if a phone battery is swollen

Swelling is usually physical, so start with your eyes and hands. Fire services list swelling or a lump, leakage, extreme heat, an unusual smell, hissing or cracking sounds, and charging that takes longer or never completes as warning signs, according to Scottish Fire and Rescue Service. Singapore’s consumer safety office also names swollen or bloated batteries, chemical leakage and excessive heat during charging as signs of suspected damage, in its lithium-ion safety tips.

In day-to-day use, a swollen battery tends to show up like this:

Android Authority adds that bumps, an unusual wobble, warped shapes and a backplate coming off can all point to swelling. If the back is sealed, as on most modern phones, the first clue may be a screen that no longer sits flat or a case that suddenly fits tightly.

A quick check without opening anything:

1. Power the phone off. Do not plug it in.
2. Lay it face up on a hard, non-flammable surface such as a stone countertop or tile.
3. Look at the gap between the screen and frame from the side, and try to spin it gently with one finger.
4. Remove any case and look at the back panel for a curve or seam opening.

If anything looks off, treat the battery as swollen. You do not need to be sure before you act.

Is it safe to keep using a phone with a swollen battery?

No. Singapore’s safety office says not to use damaged batteries and not to charge a device with a suspected swollen battery. It tells you to stop using the device and go to an authorized distributor or service provider for repair, replacement or disposal.

The reason is the chemistry. Swelling means gas has built up inside the sealed pouch. The University of Reading’s fire safety team says a swollen battery must be replaced immediately, that continued use or connecting it to power can be dangerous, and that puncturing it may cause fire or explosion. Australian fire authorities in Western Australia describe how thermal runaway can happen very quickly, producing toxic smoke and flames.

A swollen battery is not always about to ignite, and many stay stable for days. But you cannot tell which ones will not, and the damage is already done inside the cell. A relative “just needing the phone for a few more days” is the situation where people take the risk. A replacement battery is the cheaper, calmer way out.

What to do right now

Follow these steps in order. They combine guidance from fire services in several countries, since they agree closely on the basics.

1. Stop charging and stop using it. New York State’s emergency services division says to stop using the device, turn it off, unplug it, and move it away from flammable items if it is safe to do so.
2. Do not press, flex or pierce the battery. No pushing the back cover down, no pressing the bulge flat, no sharp tools near the cell.
3. Move it to a safe spot. Queensland Fire Department advises keeping damaged batteries outdoors in a well-ventilated area at least 10 metres from flammable items until disposal, per its lithium-ion battery safety brochure. That is an Australian instruction, but the principle applies anywhere: a hard, non-flammable surface, away from beds, sofas, curtains, paper and car seats, ideally outside.
4. Do not carry it in a pocket or bag. Keep it separate from keys, coins and other metal.
5. Arrange replacement. Either book a trained technician or, if you do your own repairs, source a compatible battery (more on that below).
6. Plan disposal. The old battery needs a proper drop-off, not the trash.

Some people run the battery down before handling it. Others avoid powering the phone on at all. If the phone is already on and still working, powering it off is the safer default. Do not leave it running just to drain it, especially if it feels warm.

If the phone is hot, smoking or leaking

This is an emergency, not a repair problem. Queensland guidance says that if there is fire, smoke or vapor, you should evacuate, avoid touching the device or breathing the air nearby, and call 000, the Australian emergency number. In the UK, Scottish Fire and Rescue Service says to get out, stay out and call 999, and not to try to extinguish the fire yourself. In the US, the equivalent is calling 911.

Fire and Rescue NSW notes that thermal-runaway events can rapidly produce toxic smoke, vapors, flames and metal projectiles, and it advises calling emergency services even after visible smoke or flames stop because the battery can re-ignite. So a phone that smoked and then went quiet still needs a professional’s eyes.

Why phone batteries swell

Inside a phone, the lithium-ion battery is usually a soft pouch cell. When it is stressed, the electrolyte breaks down and produces gas, and the pouch inflates like a small balloon. The University of Reading’s guidance explains that too much current can build heat and gas inside a cell, and lists overcharging, manufacturing defects, deep discharge and physical damage as causes.

A 2022 peer-reviewed study in Frontiers in Chemical Engineering found that gas generation in pouch cells is accelerated by ambient heat, high discharge current, overcharging and over-discharging. In practice, that translates to a few common habits and situations:

• Heat. Phones left on a car dashboard, under a pillow while charging, or in direct summer sun.
• Age. Every charge cycle wears the cell. Older batteries swell more often.
• Mismatched chargers or cheap, poorly made cells. Wrong voltage or low-quality internal parts.
• Physical damage. A drop, a bent frame or a crushed corner.
• Deep discharge. Leaving a phone at 0% for weeks.

The same study reports that swelling can deform or fracture housings, circuit boards, displays and cases, and can compromise water resistance. It also notes that the gases generated can include toxic species such as carbon monoxide and hydrogen fluoride. That is why a swollen battery is not just a cosmetic problem: it can crack your screen and damage the board around it.

If your phone has been running hot without visible swelling, it is worth reading our guide on phone overheating and when it is a battery problem. Heat is both a cause and an early symptom, so catching it early can save the cell.

Can you unswell a battery?

No. You will find videos and forum threads suggesting freezing the battery, poking it to release the gas, or pressing it flat. Do not do any of these. The University of Reading is clear that a swollen battery must be replaced and must not be punctured, because puncturing can cause fire or explosion. Gas is only one part of the problem: the internal layers have already degraded, so even a “flattened” cell stays unstable.

Replace it: your options

You have two sensible routes, depending on your device and your skills.

Hand it to a trained technician. For iPhones in particular, Apple’s safety guidance says the battery should be repaired only by a trained technician, because damage can lead to overheating, fire or injury. If you are not comfortable opening a phone, this is the right route, and a repair shop can also handle the old battery for you.

Replace it yourself, with the right parts and tools. If you do device repair as a hobby, a side business or part of your studies, a swollen battery replacement is routine work with the right preparation. The key points:

• Power the phone off and make sure it is not connected to anything.
• Work on a hard, non-flammable surface, away from clutter, with ventilation.
• Use plastic or non-metal pry tools rather than metal blades near the cell. A proper opening-tool set and correctly sized precision screwdrivers prevent slips.
• Never push a tool into the battery, even if the adhesive is stubborn. If the cell is stuck and bulging, stop and hand it to a professional.
• Keep screws sorted in a divided tray so nothing gets lost or mixed up between models.
• Fit only a battery that is listed as compatible with your exact model number, not just a similar-looking one.

On that last point, a battery that fits physically but has the wrong connector, capacity rating or protection circuit is a common mismatch, and it is the problem good compatibility information is meant to prevent.

Repair or buy a new phone?

If the phone is several years old, it is reasonable to compare the cost of a new battery with the price of a new phone. A guide on replacing the battery or buying new walks through the factors. A good rule of thumb: if the screen, storage and software support are still fine, a new battery is usually the better value. If the board or frame has been damaged by the swelling, or the phone no longer gets security updates, replacement of the whole device may make more sense.

Our perspective

Most swollen batteries we hear about were not freak accidents. They were ordinary phones that got hot, were charged for years with whatever cable was nearby, or simply reached the end of a battery’s life without anyone noticing.

The mistake we see people make is treating swelling as something to keep an eye on. Our view is simple: once the cell has changed shape, the right next step is a correct replacement, not more time with the old one.

That is why we put so much work into detailed product descriptions and compatibility checks. A replacement battery only solves the problem if it matches your exact model, and the most frustrating repairs are the ones where a part arrives that almost fits. If a part turns out to be incorrect or unsatisfactory, our money-back guarantee and customer support are there to sort it out quickly.

For DIYers, students and small repair shops, the same logic applies to tools. Good opening tools, precision screwdrivers and an organized parts tray make a battery swap calmer and safer for the person doing it, and for the phone.

the author

Get the right replacement battery and tools

If you handle your own repairs, our Replacement Batteries, Repair Tools and other categories cover what a battery swap needs. We list compatibility details on each product so you can match the part to your device, we ship worldwide, and our money-back guarantee applies if a part is incorrect or unsatisfactory.

For the job itself, an 8-in-1 professional opening tool set and a 5-in-1 precision screwdriver cover most phone disassembly, and a double-layer parts turnover box keeps screws in order. If you test and sort used cells in your shop, our battery capacitive tester is also listed.

How to store, transport and dispose of a swollen battery

Until it is gone, the old battery needs a safe place to wait.

• Storage. Reading’s guidance is to remove it carefully and place it in a fire-and-smoke containment bag, or a cool, dry container away from combustibles. A metal or ceramic container on a non-flammable surface, away from the house, is a sensible stand-in.
• Cover the contacts. Singapore’s safety office advises taping the ends or wires of rechargeable batteries, which prevents contact with metal.
• Keep it outside living spaces. Fire and Rescue NSW advises keeping fire- or smoke-damaged batteries at least 3 metres from structures and combustible materials. That is an Australian instruction, so follow your own local authority’s advice where it differs.
• Never use regular trash or curbside recycling. Western Australia’s fire service says damaged batteries must never go in regular waste or recycling bins, and that improper disposal has caused fires in garbage trucks and waste facilities.

Where to take it depends on where you live. In the US, look for a household hazardous waste site run by your city or county, or a battery drop-off at an electronics retailer or recycling program, and call ahead to say the battery is swollen, since some locations will not accept damaged cells at the counter. A repair shop that replaces your battery will often take the old one too. Outside the US, use your national or local e-waste scheme, such as the designated e-waste points Singapore’s safety office points to.

For air travel, a swollen battery should not go in luggage at all. Check your airline’s and your national aviation authority’s rules before you travel with any damaged cell.

How to keep the next battery from swelling

You cannot make a lithium-ion battery last forever, but you can cut the stress that causes swelling. Singapore’s safety office recommends these habits:

• Use the manufacturer’s recommended charger and follow its charging instructions.
• Monitor charging and unplug when the device is full.
• Do not charge under a pillow, on a bed or on a couch.
• Keep devices away from sunlight, heat and moisture.

To those, we would add a few practical ones:

• Take off thick cases while charging if the phone gets warm.
• Avoid heavy gaming or video while fast charging on a hot day.
• Do not leave a phone at 0% for long periods. Deep discharge is one of the causes the Reading team lists.
• Replace batteries on a schedule. If your battery health has dropped sharply, or the phone shuts off unexpectedly, plan a swap before the cell fails.
• Buy matched parts. A replacement battery chosen for your exact model, not a near match, avoids charging and protection-circuit mismatches.

If you notice the phone getting unusually warm in normal use, our overheating guide helps you separate a software issue from a failing battery.

FAQ

Is it safe to use a phone with a bloated battery?

No. Fire services and consumer safety agencies advise stopping use and not charging a device with a suspected swollen battery. The cell is damaged, and continued use or charging can lead to overheating or fire. Power the phone off, keep it on a hard surface away from flammables, and arrange a replacement.

How do I unswell my phone battery?

You cannot. Freezing, pressing or puncturing a swollen battery does not repair it, and puncturing can cause fire or explosion. The gas inside is a sign of internal damage, so the cell has to be replaced with a compatible battery and the old one recycled properly.

Can I charge my phone if the battery is swollen?

No. Charging adds heat and current to a cell that is already producing gas, which is the situation that raises fire risk. Unplug the phone and leave it off until the battery is replaced by a trained technician or by you with the correct part and care.

How serious is a swollen battery?

Very. It will not always ignite, but you cannot predict which ones will, and swelling can also crack the screen, bend the frame and damage the board. Treat it as urgent: stop using the phone, move it somewhere safe, and replace the battery as soon as you can.

Sources

• Lithium-ion batteries, Scottish Fire and Rescue Service
• Safety tips on lithium-ion batteries, Consumer Product Safety Office Singapore
• What to do if your phone battery is swollen, Android Authority
• I have a swollen lithium-ion battery, what should I do, University of Reading
• How Gas Generates in Pouch Cells and Affects Their Performance, Frontiers in Chemical Engineering
• Lithium-ion batteries, DFES Western Australia
• Lithium-ion Battery Safety, Queensland Fire Department
• Lithium-Ion Battery Fire Warning Signs, New York DHSES
• What should I do if my battery is smoking or on fire, Fire and Rescue NSW
• What should I do if my battery is damaged, Fire and Rescue NSW
• Important safety information for iPhone, Apple Support
• Battery Replacement vs. a New Phone: How to Decide, FactRated

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