When I first got my 4S the battery life was a
vast improvement over my 3GS.
Charge it up to 100% before I go to bed and it was still at 92-95% in the morning. Over the same period my 3GS would have dropped to 88-90%.
Then, suddenly - and I mean suddenly, like one night it was OK the next it wasn't - it was only 80-82% in the morning - worse even than my 3GS.
I tried turning off a load of Location Service stuff in System Services (compass, diagnostics, etc.) but it made no difference. I tried calibrating the battery by running it until the phone turned itself off then charging to 100% about 3 times - no difference.
The u/g to 5.0.1 has not made any difference.
Whatever the cause of this it is an odd problem as some people have had issues from day one, some have never had issues, and some, like me, didn't have issues but now do.
One other thing I've noticed, is that whereas before the phone wouldn't shut itself down until the battery was at 1%, last night it shutdown at 4%
I notice that someone has christened this issue "batterygate" which seems appropriate after "attenagate" and it is yet another big embarrassment for Apple.
I wonder if this will actually turn out to be faulty batteries as it seems that turning off functions that run in the background using Location Services/GPS doesn't seem to have any major impact?