Originally Posted by Modeler
You don't need a new battery, you need a new OS. After I upgraded to OS 5, my battery life has doubled. It's real! I've had the 8900 for about 9 months now, and I usually got one and a half to two days of battery life. Now I get 3-4 days.
Very true, I wouldn't go with 3-4 days but much longer than before.
ALSO there are OEM battery's for sale over several sites, not to mention being to your carrier and buying one there.
Be careful about buying non OEM battery's they can go bad very quickly/not work correctly.