Follow PhoneArena, since apps can consume some battery life on iPhone even when the user is not using them, so the best way to prevent background apps from draining iPhone battery is to go to Settings > General > Background App Refresh and disable the feature.
The trick is applied to different iPhone models
Then, go to Settings > Battery > Battery Health and enable the Optimized Battery Charging feature. Kadama says that after following these instructions, the battery on users’ iPhones will last longer.
With this approach, although iPhone battery life will be improved, applications will not update in the background when Background App Refresh is turned off. This means that updates an app normally generates in the background, like sports scores, stock market prices, or the latest temperature, won’t update until the user opens the app.
Turning off Background App Refresh won’t let apps refresh in the background
Other suggestions from Kadama to save battery life on iPhone include going to Settings > Accessibility > Motion, turning off Auto-Play Message Effects and Auto-Play Video Previews. When disabled, the feature will not allow full-screen effects to autoplay in the Messages app, and it will disable autoplay of video previews.
If you don’t feel the need for your apps to update in the background or don’t care whether full-screen effects autoplay in the Messages app, users can use the above trick to improve significantly. your iPhone’s battery life.