I'm so glad I found this! My Sprint G5 started doing this on the 19th, it even shut off and wouldn't turn back on for half an hour.. No new apps installed, nothing out of the ordinary.. I took my battery up to a full charge before work, unplugged it, and after sending a text, it restarted, and it got worse through the night. I went into a Sprint corporate store yesterday, and the associate looked on the Sprint forums to see if there were others that were having this issue, and nothing showed up.. He had me run a factory reset, and it's fixed it for the past 24 hours, and if it starts happening again, there are notes on my account that shows it's a recurring problem, and a new phone will be ordered.. That would be my suggestion, OP! Also, I noticed that after every restart, the battery would fall 10 to 15%, the time it wouldn't turn on for half an hour, it dropped over 40%!