1. Open the Apple phone to enter the main page, and click to enter the settings page. As shown in the figure below:
2. After entering the settings page, slide down, find the right option button of the battery, and click Enter. As shown in the figure below:
3. Then enter the battery page, find the battery health option button, and click Enter. As shown in the figure below:
4. Then, you can see the percentage of the maximum capacity of the battery in the battery health page. If your battery is less than 80%, you can consider changing the battery. As shown in the figure below: