Take the iPhone 7plus mobile phone (system version is iOS 12.2) as an example, and the viewing method is as follows:
1. Open the Settings application on the phone desktop.
2. Click the "Battery" option in the setting menu list.
3. Then click "Battery Health".
4. After turning on the battery health, you can see the current maximum capacity percentage of the battery in the "Maximum Capacity" option. For example, if the percentage of the maximum capacity of the battery is 95%, the loss of the battery is 5%.