Materials/tools: iPhone8 IOS 12.0 system.
Check the "battery life" of Apple's mobile phone as follows:
First, after unlocking the phone screen, click "Settings" to open it.
2. Click "Battery" on the "Settings" page to enter the next step.
3. Select "Battery Health" in "Battery" to enter.
Finally, you can see the "maximum capacity" of the battery on the "Battery Health" page. Generally, Apple's mobile phone battery will be replaced if its "life" is less than 80%.