Use the phone maker’s own battery information first; third-party apps cannot always measure remaining capacity accurately.
On iPhone
Open Settings and use the Battery section, then Battery Health where available. Review maximum capacity, peak-performance messages and any service recommendation. A percentage is an estimate, not a laboratory measurement, so consider it alongside runtime and unexpected shutdowns.
On Android
The available information varies by brand and model. Some phones show battery diagnostics or cycle information; others provide only usage data. Use the manufacturer’s support or diagnostics app before relying on an app that guesses capacity from a few charge sessions.
What to record
- Phone model and age.
- Maximum capacity or diagnostic result.
- Screen-on time during a typical day.
- Unexpected shutdowns or charging problems.
- Whether the problem follows a specific app, location or update.
When to arrange service
Stop using the phone and obtain professional advice if the battery is swollen, the case is separating, there is a chemical smell, or the device becomes dangerously hot. A low health estimate alone is not an emergency, but persistent shutdowns or severely reduced runtime justify a battery-service assessment.
Confirm the number with real behaviour
A health percentage is an estimate. Use it alongside runtime, unexpected shutdowns, temperature and service diagnostics.
- Note whether the phone lasts through your normal demanding period.
- Check for service warnings or parts history where the manufacturer provides them.
- Treat swelling, lifting panels or chemical smells as safety faults regardless of the displayed percentage.
Official sources
Facts checked: 26 July 2026. Menu paths, service rules and device behaviour can change. Recheck the exact phone, software version, account and provider before acting.
