Okay, so I have a problem. My iPhone 6 died (it runs a non-jailbroken version of iOS, I used it as a test device for development applications, but I didn't do anything crazy with the firmware of the phone). I plugged the phone in and got an Apple logo, and then it died again. It's on a loop.
What it looks like is happening is, when the phone is charging, it's above 5% battery, so it turns on. However, for some odd reason, the phone doesn't turn on all the way when it boots up; instead, it just shuts off again.
Then the phone goes back to "charging from dead" again. It's in an infinite loop.
Why would this suddenly happen? It's an unjailbroken iPhone 6 running the latest iOS (non-beta, iOS 8.4). How would I fix this?