Which ROM you mean ?? or you meant Stock GB 2.3.3 !! if so , try to Calibrate your Battery ,
Here
This wont do anything.
That app just deletes the battery stats bin file which has nothing to do with imoroving battery life. It was a myth that was debunked by a google engineer.
Basically that file is just auto generated everytime you unplug you phone.
Also battery calibration by draining and recharging is placebo because li-ion/li-po batteries do not suffer from a memory effect.
You should download betterbattstats and find out what is killing your battery. It could be a wakelock keeping phone awake instead of sleeping.
Could also be the battery itself.
Too hard to telk without more info
Sent from my GT-N7100 using xda premium