[Johnny.Bravo]

I copied this from the above xda link:

First things first, go into Settings> About Phone> Battery> Battery Use> Cell Standby. Assuming your phone has been on, or off the charger for ~10 minutes, it should show Time Without Signal at around 50%.

Next thing, press HOME, and bring up the dialer. Dial *#4636*1111# (Do not press "Call"). After a second, it should bring up the "Testing" menu.

Go into Phone Information, press MENU, and tap "select radio band." You should experience a Force Close, don't panic, this was supposed to happen. Scrolling down shows that the preferred network type is GSM auto (prl).

What this means is that even though you are connected to a CDMA network, your phone is trying to find a GSM network, preventing the radio from sleeping, and causing excessive battery drain.

Remedy this by tapping GSM auto (prl), and changing it to CDMA auto (prl).


Now your done, your TWS should drop dramatically, and you should experience much better battery life!

Note: You need to do this every time you reboot.

I changed the the dialer code to the one that blazinazn listed (the op was for the HTC Hero - the one in red is for the Epic). Once you scroll down to "Select Preferred Network Type" you can change it from WCDMA preferred to CDMA auto (prl).
I just changed mine. I'll report back in a few days and let you know what happens.