How can I improve my iPhone's battery life?
I want to improve the longevity of my iPhone’s battery life
[Re-Titled by Moderator]
iPhone XS Max, iOS 17
Question marked as
Have a look at these articles:
Batteries - Maximizing Performance - Apple
About Optimized Battery Charging on your iPhone - Apple Support
Depending on the age and use of your iPhone, and if the Battery Health is beneath 80%, the battery has to be replaced by Apple or an Authorised Apple Service Provider next to your place.
Only they have the original replacement battery for your iPhone.