how can i fix may battery health?

Hello Aljamesss,

If you are referring to the maximum capacity of your battery, it is expected that it will decrease over time as your battery ages chemically. There is no standard for degradation, and that process will vary by device and user. This resource has more details, for reference: iPhone Battery and Performance - Apple Support

If you are experiencing difficulties with your battery life, the recommendations below can help:

1. Update to the latest software.
2. Optimize your settings.
3. Enable Low Power Mode.
4. View Battery Usage information

You can find more details on each of those steps in this resource: Batteries - Maximizing Performance - Apple

Should you have any further concerns, don't hesitate to let us know.

We'll keep moving forward from there.