Apple says that they’ve solved the iPhone battery bug that’s been shutting down the iPhone 6, 6s, and 6s Plus. Users report that their phones are going dead around the time the battery hits the 30% mark.
Apple says you can find the cure by updating to iOS 10.2.1. The company says the update has resulted in a nearly 80% drop in complaints about the shutdown problem.
So, if your iPhone has been bugged by this bug, it’s time to update. Just head over to your general iPhone settings and check for the option to update the software.
Before updating, make sure you have your phone backed up.