Well there's a lot to do I think.
First of all, reduce the brightness of the screen.
Then try to edit your phone settings by changing the CPU governor to SmartAssV2. It helps a lot to save battery whether you OC your phone or not.
Do not OC your phone very high! It not only eats out your battery, but harms your phone's CPU too! Always remember that your phone comes with a factory overclock from 600Mhz to 800Mhz. 825-844 Mhz will give you a stable and fast system. Above it, the phone will become unstable and will freeze, and eat your battery.
Then, you sould calibrate your phone's battery like this:
- Charge your phone to 100%. Unplug and replug the charger at 100% to make sure you're fully loaded.
- While on charger, reboot into CWM.
- In CWM, go to Advanced settings, unplug your charger and Wipe battery stats.
- Reboot, and enjoy
Do not use live wallpapers, turn WiFi, Bluetooth, and Mobile Data off if you don't need them.
Do not use task killer apps often. Using them too often makes your phone's processor and memory load a lot, which reducec battery at a high level. The phone will reload those apps what it needs, but if your phone is slow, do clean memory. I advise using Advanced Task Killer. But remember, not too often! :P
I think this is all that you can do, hope I could help a bit
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