Plenty of us got this problem, battery go down so quickly. In my case battery use to stand by for 12 hours roughly. Few people mentioned in other threads their own solutions. My solution is, Install Juice Deffender (free app) - you can download it from Market, enable Juice Deffender then make a widget shortcut of Juice Deffender on one of the home screen - APN. I keep 3G off most the time as i dont need it when i do then i turn on quickly by clicking on that shortcut. I dont really know why do i keep Juice Deffender on while 3G is off. My battery from 12 hours went to 30hours. I do listen to music alot few hours per day. @Offtopic has anyone got clue about whats going on with that root thing on x10 ?