UPDATE 11/11/11 Apple release iOS5.0.1 last night
Apple recently admitted to battery problems, not only in it’s new iPhone 4S but also in iOS5. Chatter would seem to indicate that apple is working hard on a fix. Apple developers will note that iOS 5.0.1 went to beta 2 last night.
From my own experiences, the problem seems to lie in leaving certain applications running in the background. Whilst i haven’t been able to prove this yet, it does statistically seem to be hint in the right direction.
In the mean time whilst it wont sole the main problem, there there is one trick that you can do to help reduce battery consumption;
One of the big consumer of power is the GPS receiver of “location services”. iOS5 uses this to optimize several setting on the phone including the time zone you are in. However it seem leaving these switched on means the GPS in running all the time, draining the battery. The Chalenge is however the setting are buried;
Go to Settings -> Location Services
Now scroll right down to the bottom to reveal the extra settings in “System Services”
Select Systems Services
Now switch off as many of these as you really don’t need, but most of all switch off the “Setting Time Zone” & “Cell Network Search” (yes mine is on in the screen shot, but its not on any more!)
For the most part I switch of the location service master switch as well when I don’t want to use the GPS. Hope this helps.