[LG Nitro HD] sixline:
Disclaimer: Although there is very minimal risk but I am not responsible for anything happening to your device, do it at your own responsibility.

Sorry for my bad English.

Hi guys! I am using this device since a week but its battery life was pathetic even on stock rom and Engineer Version. I decided to switch to cm as it has the best battery life for all devices and I flashed OptiBean RC2 by mac20dnangel and found out the same pathetic battery life. I mostly use 2G and wifi, a few calls and texts and battery was going flat after 5-6 hrs. I checked in Settings>Battery and found out that the most battery eater was Android OS which was about 70%. So, I searched the forums and found many helpful threads (thanks to all those devs) and did following things. Now, my phone's battery can last a whole day easily and Android OS under settings>battery has come down to 7%.

First of all I turned off Location Services as the GPS service was involved in a CPU WakeLock even GPS was turned off in Settings>Location Access.

Also, the following system apps were real battery hog. So I turned them off. For doing this, go to settings>apps and click ALL tab. Tap on the app and tap disable. I disabled following apps:

1. Android Keyboard (if you use some other keyboard. i am using smart keyboard pro)

2. Apolo or Music app (if you don't use it as i am using jet audio plus)

3. DSP Manager (which was always running in the background and was a major battery hog. Many people like it but we have to live without it)

4. CM Updater

5. Exchange Services (if you don't use them)

6. Face Unlock (if you don't use your face to unlock screen)

7. Google Search (i don't use it)

8. Google Text to Speech Engine (also was a major battery hog)

9. Pico TTS (same as above)

10. Messaging (i use go sms)

11. Picasa Uploader (if u don't use it)

12. Search Applications Provider

13. Google Talk (i don't use it. don't disable if you use it)

14. Talk Back ( was a major battery hog)

15. Voice Dialer (if you don't use)

Also, always turn off wifi, bluetooth, gps, autosync, 3G/4G, auto rotate when not in use. Live wallpapers are also major battery eaters.

After that I installed Auto Killer Memory Optimizer which is free on Play Store. Open this app and tap on the wrench icon present in upper right corner. Tap advance system tweaks.Check Apply on boot and 2 min delay before applying. Check Memory Management, Battery, Sleeper, UI and Network. Now go back and check Apply Settings on Boot, Enable Advance Mode, Enable Kill on Click. Now hit back key to return to app's main screen. Tap on change and select strict or aggressive as you like. Close app and reboot.

After that I calibrated my battery. To calibrate, charge your phone to 100%. When battery indicator reached 100%, unplug and plug again after 10 sec to be sure that its 100%. Now pull and re-insert battery. Then connect your charger to be sure that it is 100% charged. Now unplug and reboot to recovery. In advance select wipe battery stats. Then reboot device. Now you can use your device but don't plug the charger or data cable and let the battery die as you normally use the device. When battery reaches 0% and device turns itself off, power on again to make sure that battery is actually dead. Now, plug in your charger and charge the battery to 100% in one shot. Once more, let it die by itself without charging the device. After battery is fully dead charge it again to 100% in one shot. After these steps battery should be calibrated perfectly.

One more thing, go to settings>developer option, uncheck Force GPU Rendering and check Kill app back button. Now you'll able to kill any application in the foreground by long pressing back softkey. Use this to kill games and other battery hogging apps when you want them to exit.

I hope after doing all these steps you'll find an improvement in battery and I believe these tips can be used in any ROM and any device.;)

Edit: Don't hope for battery lasting to 2 or 3 days as the massive screen used by this device consumes a lot of battery and 1830 mAh battery is just not enough for this device. Try to buy an extended battery if you want more juice.