Love my Otterbox, hate the 4-hour battery life. Thanks
A couple of things that could help your battery life are in no particular order:
1) If you don't use Google Talk turn it off. Talk by default automatically signs you in. Check it after each OTA update or Data Reset. Go to Talk<Menu<Settings<Uncheck Automatically Sign In<Use back arrow<Hit Menu<Touch Sign Out.
2)Sprint Zone. I don't personally use this Sprint Software Tool but I think some things need it (not for certain). Anywho Sprint Zone<Menu<Settings<Scroll to Bottom Tap Set Update Frequency... I set it to update Once a Month.
3)Last I use My Settings App to make sure my screen brightness is at 35% or so. If I'm out side I just turn it up to 75%. The My Settings App allows you access to many things, Airplane Mode, Wi Fi, Bluetooth, Ringer Mode, GPS, Screen Timeout, Sync, 2G/3G and Lock Screen. there are others as well that's the app that was suggested to many when i picked up my Evo4G.
4) Amazon App Store and Amazon MP3 is another one you may need to be careful about because I believe you need to sign in and out. I am not for sure but it may run in the background if you don't sign out. Early Mon or Marctronixx may be able to speak to this?
Those three things really help with battery life. Hope this helps.
Charles
PS I love My Otterbox Too Can't say enough about my Defender Case!