this happens to me all the time. Im getting the iphone 5 in a couple weeks but this drives me absolutely crazy. At random times, whether its 100% or 20% or anywhere in between, my phone shuts off at the most random times. (at least 20x a day.) when i plug it in, it stays on the apple logo for about 5 minutes, then either turns on for a few seconds to my homescreen, or turns to the "low battery sign." and turns off. then i have to wait 1/2 an hour before it turns on and finally stays on. it stays on if it is plugged into my MacbookAir or into the wall. It crashes when im using pingertext free (i dont have a sim card because its in my dads spare phone) and facebook, but crashes anyway. this is really getting old and i have some important people i can only contact throuhg my phone..it also doesnt show my messages or texts most of the time. please help what should i do?