draining up to around 10% overnight with nothing on. nothing in the background, i even put it on airplane mode so it wasnt trying to look for a connection. did a dfu restore and set up as new. and it wasn't a 10.1 problem because it happened even before that. still the same. they ended up swapping it out at the store. no problems now. but at least they were cool about it and didn't offer just a battery replacement. sometimes just being nice counts. cool thing is that this phone is unlocked now.