Before you root, try this:
Go into your settings and go into Location Services. Uncheck all 3. You WILL see your battery life improve big time. What really drains your battery is most likely you syncing a lot of accounts and you having location services turned on whereas then google maps constantly tries to get your location, thus you have partial wakelock waking your phone even when screen is off. Now try to see what accounts can you do without much syncing such as Facebook, gmails, etc. These 2 are 2 of the most basic battery drainers known.
And of course the above is also right, media scanning kills..but you'll need to root to solve that problem.