As the title states my iPhone 6s would randomly power off when the battery is reporting anywhere between 20 and 40%. If I press the power button I'd get the icon indicating drained battery. If I plug in a power source the phone turns on and still shows 20%+ of battery. If I unplug after a few minutes it'll turn off again. Took it to an Apple Store and they said the battery is fine and that I need to do a clean install (as I've already attempted a full install/restore). Kinda find this ridiculous to be an acceptable solution. I'd lose all my app settings, text messages, and HealthKit data. Anyone experience an issue where the phone would always power off when it shows over 20% battery?