Materials/tools: iPhone8.
Apple's mobile phone checks the "maximum capacity" of the battery with the following steps:
First, open "Settings" on the phone desktop.
2. Open "Settings", find "Battery" and click "Enter".
3. Click "Battery Health" on the "Battery" page to enter the next step.
4. On the current "Battery Health" page, you can see the "maximum capacity" of the battery (it is recommended to replace the mobile phone battery if it is less than 80%, and the remaining 80% of the "maximum capacity" of the Apple mobile phone after two years of use belongs to normal use).