The iPhone has offered a way to extend battery life for many years. Through a feature Apple calls Low Power Mode. However, it isn't quite as full-featured as the Battery Saver that's built into some Android phones. The idea is to limit some of the less critical activities and processes when battery life is running low. The good news is that there is a relatively easy way to expand the usefulness of Low Power Mode so it can switch on automatically or request permission from the user.
Apple gave
Read more on screenrant.com