[Epic 4G Q&A, Help & Troubleshooting] iModMM:
My tips you can add:

1. I always, no matter what, always have brightness on lowest setting! If you have a hard time seeing in sun, than do auto, but turn off when don't need to, I have on low 24/7. Then at night, I have this app called screen filter which lets you lower brightness then default setting(good on eyes).

2. I always have auto-sync off. If you want emails etc. configure with ur preferences. And most of the time background data. But with background data off, you don't have access to market and have to enable for use. Don't get notifications. Lately, haven't been getting WhatsApp messages. This is optional.

3. In wifi settings, network notification turned off. Haptic feedback and all vibration disabled. Sounds on key clicks or anything disabled. Auto rotate screen off. No window animations. Screen timeout, 15 seconds. Keyboard timeout, 3 seconds. In location, use wireless networks and gps satellites unchecked.

4. No live wallpaper! No bright colors! I use a black background for wallpaper!! Try to go a little dark, not bright, stay away from white! Id recommened, the full black wallpaper. Also on ur homescreen, avoid widgets! Especially ones that use live web feed like, facebook, scorecenter. These are battery suckers!

5. I delete all apps I do not use! Stock and user. Download titanium backup to fix this issue. I freeze, system updates, swype, drm content, drm content launcher, sns, snsaccount. I uninstall the stock browser, use dolphin!! I also uninstall, all sprint bloatware, my files, gmail, email, talk, news and weather. Uninstall all stock and user apps you don't use! Check spare parts to see what runs in the background that you don't use. Another thing to add, I uninstall swype and android keyboard and use better keyboard gingebread edition 8.

6. Disable refresh interval in facebook, do it manually when you are going to use it!

7. Use setcpu. Undervolt to 800max and 100min on conservative governor. Set profiles, when phone is locked and etc.

8. Now lets talk about juicedefender and task killers. Juice defender will work and is a good app! BUT: if ur a person like me, I text a lot in whatsapp and when u lock screen it disables data, so u wont get texts. Download it, take a look at it, try it out. I recommend using agressive mode. Now lets talk about task killers. Personally, I think they dont work at all, and actually waste battery then save it. I just would say don't use one, and use samsungs stock task killer(actually works!)

9. Use a custom rom and kernel. Always be up to date on updates. I usually use, SRF and midNight. All about preference.

10. Extended battery FTW!!! Buy a seidio extened battery! May cost some money, but will greatly increase battery!!! Or get a cheap asian knockoff on ebay.

11. Disable data and put phone into airplane mode when it wont be in use for a period of time. Like at school or work. I usually keep data off during school. You will see a difference with data on and off.

12. Always keep wifi, bluetooth, gps, 4g off when not in use. They will drain battery crazy!!! Wifi will search for networks constantly, same basic thing with gps and bluetooth.

13. Also do full charges!! At night shut off phone and let it charge for a good 8 hours. Then in morning, turn on still plugged in. The charging indicator will be red, leave it alone till its blue. Go get dressed and eat some breakfast lol. Then when you come back it should be blue. And when on boot, let it finish media scanning, don't interrupt it!!

I can guarentee if you follow my tips, you will see a significant increase in battery life!

These are my tips!! I will add more if I can remember some more!

Typed this all on my Epic!!