[EVO 4G Q&A, Help & Troubleshooting] ImJacksAmygdala:
I will take a shot at helping you by telling you what I did. I honestly didn't believe the battery life reports with high performance until I saw it for myself. I know it looks like a lot but it will work.

Go here and read all of Calkulin's posts. Install the EViO 1.1 ROM and the Kings BFS#5 for EViO kernel that Calkulin links in one of his posts in that thread. Use latest Amon_Ra and wipe everything twice. Yes it utilizes HAVS.

http://xdaforums.com/showthread.php?t=745205

I read somewhere it was a good idea to remove SetCPU before flashing new kernels. I guess uninstalling prevents the auto detection settings from becoming corrupt between kernels. Also make sure you're using SetCPU v2.02 as recommended by Calkulin.

http://xdaforums.com/showpost.php?p=7821664&postcount=1233

Update your radios to the latest. Update your PRI and PRL for optimal radio efficiency. LOL good luck with the PRI...

http://xdaforums.com/showthread.php?t=715485

When attempting to update the PRI I had to flash Fresh ROM with stock Kernel and do the ##786## method which includes factory reset. You must have your phone's MSL. I got my MSL using the free MSL Finder app on the market. You can always nandroid back when you finally get it. Took me a couple tries once I switched ROMs. Not a clue why or if it truly made a difference I just read that one guy added up reports of success while using Fresh ROM. I read a report that said updating the PRI will improve the efficiency of the radio in the way that it transmits and recieves between towers. I have no proof of this I did not save the link. But it certainly can't hurt and may improve radio power consumption.

http://xdaforums.com/showthread.php?t=753233

Wipe your battery stats and calibrate your battery as per these instructions. Be sure you see the phone says full not just the green LED.

http://wiki.cyanogenmod.com/index.php?title=Troubleshooting#Battery_recalibration

After completing the calibration and the phone has a solid set of battery stats recharge completely and then follow this guide.

http://xdaforums.com/showpost.php?p=6796078&postcount=1

Use Set CPU overclock to 1.15 but keep Calkulin's profile. Or you can lower the max clock to conserve more battery.

Follow this guide. NOTE on step 5. I like my GMAIL to push so I leave background data enabled. Google is the only auto-sync I leave enabled. I disable weather and everything else from syncing. It's up to you just making you aware of that disabling Background Data can prevent instant emails.

http://www.goodandevo.net/2010/05/20-tips-to-improve-htc-evo-4g-battery-life.html

Once that is all set use System Panel and follow this guys advice. Use a combination of Spare Parts app battery history information and System Panel's monitoring of apps to verify no apps are burning your battery.

http://xdaforums.com/showpost.php?p=7873703&postcount=2

Im still looking into the CDMA only settings but I read in the network app user comments that its no longer required in 2.2 to prevent your radio from wasting battery life using the GSM radio. I am still researching this.

Hope this helps. This is what worked for me. If you actually have some time and determination to follow all of these steps you will see some amazing results.