I guess I am late to the party since all the other post about this are over a year old. But I wanted to let anyone else know that I had terrible battery life lately, and as you said "Cell Standby was up about 25%. Purchased new battery and deleted a few apps that I really liked, then checked and found "Enhanced 4g LTE Service." was checked or turned on. I turned it off and it is now doing much better and even charges faster. just went 10 hrs off charge overnight and only down to 75%. Now that I think about it I kind of remember turning "Enhanced 4g LTE Service." on a few weeks ago while chasing a data roaming problem with at&t Customer Service.