Originally Posted by Richb
Make sure your firmware is upgraded to at least 18.104.22.168
If you're AT&T, you are probably already there; if you are TMO, you may not be. There is a vast difference in battery life with the newer firmware.
You can learn more in the Curve8900 section of the forums.
ITA - early 8900s had poor battery life - later OS releases have made a difference. I have one of the first AT&T devices with 22.214.171.124 and the worst
I have ever seen at the end of a 24 hour day is 48% battery remaining - if I don't do too much playing around with the device I may have as much as 75% remaining. Talking on the phone seems to take less out of the battery than "fooling around" with it.
There's a lot of power saving features in the late OS versions, including CPU speed controls which may help explain why later versions are better than earlier ones.