I upgraded the OS on my new 4s to 5.0.1. yesterday. I wasn't working today so the phone has been idle (standby) most of the day. With wi-fi on at 7:45 am, the battery was at 100%. I checked every half hour. through 11:39 am, about four hours. The battery was still at 100%. Then I switched on "3G" in network settings. The phone remained in standby. An hour later, the 100% dropped to 97%, and a half hour later, to 95%. Just an observation...not proof or evidence of anything.