A phone battery probably needs replacing if it drains much faster than it used to, switches off at 20 or 30 percent, gets hot during normal use, or if the back or screen is lifting. A swollen battery is a safety risk: stop using and charging the phone.
Every phone battery wears out. Each charge slightly reduces how much it can hold, so a battery that lasted all day when the phone was new will last less and less. Knowing the signs helps you replace it before it starts causing other problems.
The signs of a worn battery
- It drains much faster than before. You are charging twice a day when once used to be enough.
- It switches off at 20 or 30 percent. The percentage looks healthy, then the phone dies. That is a battery problem, not a software one.
- The percentage jumps around. It drops from 40 to 20 in seconds, or shows full and then falls quickly.
- The phone gets hot during ordinary use or charging, without heavy apps running.
- It struggles when it is cold, or under load such as a video call or a game.
Check the battery health setting
iPhones show a battery health figure in Settings, under Battery, in the Battery Health and Charging screen, with a Maximum Capacity percentage. Some Android phones show battery health or battery information in their settings too, but many do not, and the menus vary by maker. If yours does not have it, judge by how the phone behaves.
Rule out other causes first
A quick drain is not always the battery. Before replacing it, check:
- Apps running in the background. One misbehaving app can flatten a battery.
- Screen brightness and settings. A bright screen and constant location use drain quickly.
- Software updates. Pending updates can affect battery life.
- The charging port and cable. Poor charging can look like a weak battery. See why your phone might be charging slowly.
A swollen battery is a safety risk
If the back of the phone is bulging, the screen is lifting away from the frame, or the case no longer closes properly, the battery may be swelling. Stop using the phone, stop charging it, and do not press on it or try to open it. Keep it away from heat and bring it in as soon as you can.
Replacing it
A battery replacement is a common, usually straightforward repair. We check the battery and the charging port together, because a worn port can look like a tired battery, and you get a quote before any work starts.
Frequently asked questions
How long does a phone battery last?
There is no single answer. It depends on the phone, how often you charge it, how hot it gets and how it is used. Watch how the phone behaves rather than counting years.
Is it safe to keep using a phone with a swollen battery?
No. Stop using it and charging it, keep it away from heat and get it checked quickly.
Can a software update fix a draining battery?
Sometimes. Updates can fix bugs that use extra power, so install pending updates and restart the phone. If the phone still drains fast or shuts down early, the battery itself is the likely cause.
Having a phone or laptop problem? Bring it in: diagnostics are free and you get a quote before any work starts.
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