Apple Releases iOS 10.2.1 With Bug Fixes, Performance Improvements

If it's shutting off randomly and you have an iPhone 6 for over a year and a half I can almost bet the battery is just consumed. Why don't you have a diagnostic run over the phone or in the store. And if you're wiping the phone are you restoring from a backup? Because that essentially does nothing. You're just taking out the bad oil in your car and putting it back in when you restore from a backup. You have to set it up like new to actually test it out. If it continues happening it is most definitely not a software issue it is a hardware issue and the battery is mostly likely consumed. If you have a 6s and it randomly shuts down then the battery is probably one of the ones that qualify for the replacement program and it needs to be replaced. And if it's a 6s that doesn't qualify but has the issue after wiping it and setting it up like new without a backup then it most likely just still has warranty left and it has the battery issue anyway and needs to be replaced. If it was a software issue with the actual OS then everyone who is running iOS 10, I mean EVERYONE would have the same problem and that is definitely not the case.

/r/apple Thread Parent Link - macrumors.com