What to know about phone batteries
Every phone battery wears out. It loses a little capacity each time it charges, so after two or three years of daily use, most phones don’t make it through the day the way they used to. The good news: a new battery is one of the quickest, most affordable ways to make an older phone feel new.
How to check battery health
- iPhone: open Settings, then Battery, then Battery Health. Below about 80 percent Maximum Capacity, or a Service message, means it’s time.
- Samsung Galaxy: open the Samsung Members app, tap Support, then Phone diagnostics, and run the battery test.
- Google Pixel: newer models show battery health under Settings, then Battery.
- Laptops: on a Mac, open System Settings, then Battery. On Windows, run
powercfg /batteryreportin Command Prompt.
Why a worn battery makes a phone slow
As a battery wears, it can’t deliver power as quickly. To avoid shutting off suddenly, phones slow themselves down when the battery can’t keep up. That’s why a phone with a worn battery feels sluggish, and why it may die at 20 or 30 percent, especially in the cold.
A new battery fixes both: the phone gets its speed back, and the percentage on the screen means what it says again.
Swollen batteries: stop and bring it in
A swelling battery can push the screen up, pop off the back glass, or make the phone rock on a table. It’s a sign the battery is failing. Don’t charge it, don’t press on it, and keep it away from heat. Bring it in as soon as you can, and we’ll take it out safely.
Make your new battery last
- Keep it out of the heat. A phone on a car dashboard in an Alabama summer wears its battery faster than anything else.
- Turn on optimized or adaptive charging, so the phone holds at 80 percent overnight and finishes just before you usually unplug it.
- You don’t need to run it down to zero. Modern batteries are happiest topped up anywhere in the middle.
- Use a decent charger and cable. Cheap chargers can charge slowly or run hot.