To understand why your battery is bad, if that is what you are asking, we'll need some info.
First, charge to 100%, use the phone normally for a day, then make a screenshot of your battery usage stats and post it here. You'll need to register as a member to do that....here's how:
http://forums.androidcentral.com/showthread.php?t=409154
Anything you're unsure about, just say.