have you done this? - wifi only when you use it - wifi to 10 mw - mobile internet only when you use it - bluetooth only when you use it - tap-vibration off - dont leave windows running when idle - brightness on 1/2 - 10 seconds to standby - no widgets at all - gps off - energy save modus screen - not logged in to not used accounts unnecessary - fm transmitter off - energy save modus wifi - no automatic mail updating - no automatic wifi checking