A phone battery slowly loses capacity as it ages. Checking battery health tells you how much of the original capacity is left, which is useful before buying a used phone or deciding whether to replace a battery.
Check Battery Health on iPhone
- Open Settings > Battery > Battery Health & Charging.
- Look at Maximum Capacity. This is the battery’s capacity compared with when it was new.
On iPhone 15 and newer, you can also see the cycle count, manufacture date and first use date in Settings > General > About. Apple treats 80% or more as normal for a battery within its rated cycles.
Check Battery Health on Android
Samsung Galaxy
Open the Samsung Members app, go to Support > Phone diagnostics and run the Battery status test. It shows the battery’s life as Good, Normal or Weak.
Google Pixel
On newer Pixels, open Settings > Battery > Battery health to see the estimated capacity.
Other Android Phones
- Some phones open a testing menu with battery details when you dial *#*#4636#*#*. This does not work on every phone.
- A battery app such as AccuBattery estimates capacity after it has measured a few charge cycles.
When Should You Replace the Battery?
- Capacity is below about 80%.
- The phone shuts down suddenly at 20% to 30% charge.
- The battery drains much faster than before with the same use.
- The back or screen is lifting. A swollen battery is unsafe; stop using the phone and get it checked.
Use an authorised service centre for replacements. Cheap local batteries often have lower real capacity than printed on them.
Tips to Keep Your Battery Healthy
- Avoid leaving the phone in heat, such as on a car dashboard in summer.
- Use a good charger; see our mobile chargers.
- For long load shedding, a power bank is easier on your routine than draining the phone to 0%.
Shopping for a phone with a long-lasting battery? Browse our big battery phones.
