Go to Settings → Battery → Battery Health. A battery is considered worn once its maximum capacity drops below 80%, or when iOS shows a Service message. Replace it if your iPhone dies early, shuts off unexpectedly or feels slow.
How to check your battery health
Open Settings → Battery → Battery Health (called Battery Health & Charging on some versions). Maximum Capacity compares your battery to when it was new. Peak Performance Capability tells you whether iOS is limiting performance to prevent shutdowns.
On iPhone 15 and later you can also see the cycle count and manufacture date under Settings → General → About.
What the numbers mean
- 90–100%: healthy.
- 80–89%: normal wear. You'll notice shorter battery life.
- Below 80%, or a Service message: worn. A replacement is recommended.
- Peak performance message: after an unexpected shutdown, iOS may slow the phone to prevent another one. A new battery removes that limit.
How long iPhone batteries last
Apple designs iPhone 14 and earlier batteries to keep 80% of their original capacity after 500 full charge cycles, and iPhone 15 and later after 1,000 cycles. Heat is the biggest factor in how fast a battery ages.
Make your battery last longer
- Keep it out of the heat: car dashboards, direct sun, charging under a pillow.
- Turn on Optimized Battery Charging, or the 80% limit on iPhone 15 and later.
- Keep iOS up to date.
- Don't leave it sitting at 0% for long periods.
- Use good-quality cables and chargers.
Signs you need a new battery now
A swollen battery can push the screen away from the frame. If you see the display lifting, stop charging the phone and get the battery replaced. The same goes for shutdowns at 20–40%, getting very hot while charging, or draining in a few hours.
Genuine and third-party batteries
Depending on the model and the part, iOS may show a parts message for a non-genuine battery, and on some models the health percentage won't display. It doesn't affect how the battery works. We'll explain your options before any work starts.
Frequently asked questions
Is 85% battery health bad?
No, it's normal wear. You'll get a bit less battery life than when the phone was new. Most people replace the battery once it drops below 80%.
Will a new battery make my iPhone faster?
If iOS has been limiting performance because of a worn battery, yes. A new battery removes that limit.
How long does an iPhone battery replacement take?
Usually under an hour at a store. Mail-in repairs take 7–10 days door to door, including shipping both ways.
Related repairs