My iPhone 13 was losing around 40% of its battery overnight while sitting idle. Resetting All Settings completely stopped the drain for a while, but as soon as I charged the phone again, the heavy overnight drain returned. I'm not sure what triggers it or whether this points to a software or battery problem. Has anyone experienced something similar? The battery health is currently 92%, and the phone is running iOS 26.6.
3 Answers
The important comparison is whether the battery drops only overnight or continues draining quickly during normal use. If it loses about 40% while idle, take a screenshot of the Battery graph and the App and System Activity list immediately afterward. That information should help identify whether this is an app issue, a network problem, or a hardware fault.
A 92% battery health reading doesn’t automatically indicate a faulty battery, so it’s worth checking what is actually using power. Look at Settings > Battery after an overnight drain and check whether a specific app, background activity, poor signal, or an iOS process is responsible. Also note the iOS version and, if possible, the battery cycle count and service information.
Reset All Settings can temporarily clear a stuck system setting or background process, but charging itself probably isn’t causing the drain. Since the problem returns, check Battery usage, install any available iOS update, and review Background App Refresh, location access, and cellular signal. If the battery usage still looks abnormal with no clear app responsible, back up the phone and consider a full restore or having Apple run diagnostics.
The battery health is 92%. I’m not sure how to check the cycle count on an iPhone 13, but the phone is running iOS 26.6.