20-40 hours for light moderate to heavy moderate use.
When I say heavy moderate...I am accurate!
I am using Toast full Nand root with Fresh .3 rom....
Here is my battery trick....
If you are experiencing poor battery performance, you might be experiencing the Motorola cell tower problem. HTC has confirmed that the EVO is not playing well with cell towers that have motorola transmitters. It is causing the phone to use more energy to dial in the tower.
To be sure...
1. Set all apps and widgets to manual update or update once a day.
2. Get rid of the people app or widget from any home screen.
3. Go into Gtalk and uncheck auto sign in. Then sign out when you exit the program.
4. charge the phone until the green light comes on. Don't use a battery meter. The second the green light comes on, go into recovery and wipe the battery stats. Reboot the phone and run it until the battery dies and will not longer power the phone. This does nothing for the battery but does recalibrate the internal battery meter. Some of the posts about plugging in and out at green and orange light....waste of time.
5. For maximum life...turn off: background data, WiFi, BT, and Mobile networks when not using. keep screen at 1/2 brightness.
If I do the above and manually update mail, weather, social apps, etc... and only turn radios on when I need them, I can get 40 hrs. out of my EVO and this is under moderate to high moderate use.
One other thing....plug your phone in for 10 minutes. Then unplug it and go into immediate stand by for like 30 minutes. Go to settings>about phone>battery>battery use>cell standby. Time without signal should be very low....anything over 10-15% and I'd suspect that if you did everything in 1-5, you have a towers issue robbing your battery.
http://forum.xda-developers.com/editpost.php?do=editpost&p=6934368