I read a post somewhere -- whether this thread or another I don't know -- about a user who went to the Genius bar about battery drainage issues. The Geniuses ultimately did a clean restore of the user's phone, set up as new, and the drainage issues supposedly were much improved.
My phone had been losing 7% an hour without me using it. What harm could a reinstall do right? So I did a DFU reinstall of iOS 5 , setup the phone up as new and reinstalled my apps and settings by hand.
After the reinstall I went to sleep. The phone was at 100%. 4 hours and 54 minutes later I woke up, hit the home button and it was briefly still at 100% then dropped to 99%. There was 8 mins of usage.
I was hopeful. This was a hell of a lot better than the 7% per hour I was losing just yesterday but I had a feeling it was too good to be true.
I didn't use the phone this morning except to plug in my earbuds (which have a mic) and drive to work. Along the way I only used Siri a little bit, asking time and weather, sending a twitter update or two via text. 87 mins of standby (which includes 24 mins of usage) since first hitting the home button this morning, the phone dropped another 6%.
😕
For what it's worth, my setup includes 2 push email accounts (MobileMe and Exchange, both of which sync contacts and calendars as well), 3 fetch email accounts (fetch set to 30mins), all Location Services turned on except Find my iPhone, Diagnostics & Usage and Location-based iAds, brightness at about 50% (auto-brightness on), Wifi on, BT off.
PS -- in 41 more mins of standby (19 mins usage) it's down another 5%. Clearly there has to be some service running on the device that is started up (perhaps Siri related?) that is chugging along eating resources.
