iphone 5 shuts off randomly - buttons not recognized to restart
I've had this happen twice so far on an iPhone 5 64gig model. The first time my phone just suddenly powered down - instantly - and it did not respond to any buttons as I tried to power it back up. I thought perhaps the battery was dead and plugged it in - later I checked the phone and it was on and fully charged. Then it happened again - with the battery at 97% I was actually on the speaker phone using my iPhone 5 (with a call to Verizon to setup autopay) and then the call suddenly ended. The iPhone was off - holding the power button did nothing, even trying the "hard reset" option with the home and power buttons did nothing. I then took the phone and plugged in the cable so that it would charge. The phone continued to not recognize any buttons until about 30 seconds after being connected to the charger at which point it booted itself up and showed my battery nearly full. I disconnected the phone and there sat my battery at 97% charge.
Has anyone else seen unexpected behavior like this? I figure I'll take it in to the Genius bar for a swap, but would prefer not to have to redownload all my apps and set all my passwords back up.
Thanks,
James