3 of 14Image
Drop the screen brightness
One of the easiest ways to improve battery life on the iPhone is to drop the screen brightness. When I updated my iPhone 4 from iOS 4 to iOS 5, Apple jacked the brightness up to an unnecessary ’supernova’ level. Unless I’m outdoors, I usually keep my screen pretty dim.
Settings > Brightness
Auto-Lock the screen
Another tip that makes a big difference is to lock the screen after a short interval. This helps conserve battery life because it turns the screen off when your handset is not in use. Set it to go off after a minute or two.
Settings > General > Auto-Lock
Selectively turn off/on radios - WiFi
If you don’t need WiFi or Bluetooth or 3G, turn off the radios!
Settings > WiFi
While you’re here, disable Ask to Join Networks unless you use this feature often (just turn it on when you need to find a new network).