Here are some tips on how to maximize your cellphone battery:

Charge according to manufacturer specifications.
Don’t undercharge.
Don’t overcharge.
Turn off your keypad beeps.
Shorten the time your backlight is kept on.
Turn off your animated screensaver.
Lower volumes to the lowest possible setting that you can still hear (Depends in your surroundings. Volume on max still can’t be heard in very noisy places).
Turn it off when there’s absolutely no signal. Your phone will use much juice in attempts to find a network.
Never expose you cellphone to extreme heat like on the dash or under direct sunlight.
All batteries will run out. Every charge reduces it’s capacity even by just a little bit. Take not of charge cycles, a typical Li-Ion battery can have 300-400 cycles. Which means you might have to replace your battery once every 1-1.5 years.
Depending on your use, following these tips may give you more mileage from your cellphone battery. I once had a phone (w/ the same battery of course) that lasted me a good three years.

* SoURCE: http://www.lifespy.com/2007/how-to-m...phone-battery/

Never heard of this but what I do to maintain a good battery life is to recalibrate it at least once every 2 months. You do this by draining the battery completely before charging it.

I tried the code *3370# to restore my battery power to 50% and it worked about 2 months ago and I was down to 10% and tried it again and it didn't work. Does anyone know why or if the code has changed or if it is wrong. Thanks