mobile

Can anyone think of a reason why my phone would reset itself ONCE each time I put it on charge after about 10 - 20 minutes? Surely if the battery were overheating then it would continually reboot itself as the phone remains plugged in, but nope; just the once. It doesn't feel particularly warm to the touch when it happens, either. I thought it might be performing some maintenance on itself the first time it happened, but then I released that wasn't likely when it kept happening. Any ideas?