Battery of iPhone 7 with ios 15.8.1 drains so fast within 10-15 minutes (10-15%)
i have just purchased a secondhand iphone 7. the battery has already been replaced before i bought it so it's at 100% health. however, the battery drains so fast with little use. i checked in the battery section and seeing that apps are only being used for minutes at a time, yet the battery drops way too much, way too quickly.
i get that it's an old phone. but i wasn't expecting it would be this bad. does anyone know what to do?
iPhone 7