The Samsung Galaxy S2 Plus Battery Life has been a big problem for its users.
Massive battery drop has been a main concern and also overheating which has been giving Samsung fanatics a very hard time.
S2 Plus users have been ranting all over forums about the battery life of their phones saying things like, “My samsung galaxy S2 Plus batteries suddenly drain within hours!” and “My battery drains like there’s no tomorrow!” If you’ve been experiencing the same problem, look no further, if your phone could only last 10 hours on stand by, now you can have your S2 Plus run for as much as three days! Learn how to extend your Samsung Galaxy S2 Plus’s battery life here: Switch To GSM Only Mode as much as possible if you’re not using 3G, Wifi, Bluetooth or GPS.
This will leave you to use the basic functions of your phone but would extend the battery life immensely.
Turn Off Wi-Fi when not in use.
Getting signal from an outside source could really stress the battery and could cut the battery life to 50%.
Turn Off GPS.
Almost the same concept of turning on the Wi-Fi, this is a huge battery eater as well.
Close Camera App.
With the camera running and the display screen showing large amounts of moving colors, not using the camera would really help save a huge amount of power.
As much as possible, try not to use camera too much.
Screen being bright would definitely hurt your battery, adjusting display brightness to low would really help extend phone usage.
Say “No” to Android Live Wallpaper.
Just like the camera app, too much movement on the screen would burn your life down.
As much as possible, keep your phone as stable as possible.
Proper battery maintenance could help extend its life.
Clean the battery contacts at least once or twice a month.
Use the original AC charger as much as possible.
Avoid charging via USB, it could spoil your battery.
Charge when your phone drops 10%.
Also, as stated in the manual, avoid exposing your phone to extreme temperatures.
Lastly, recalibrate your battery.
Taken from androidforums.com , as stated by user juo78: 1) Drain all of your battery until phone shuts down 2) Turn on and drain battery until phone shuts down (repeat until you are unable to turn the phone on- this step is very important because we need to drain the battery completely) 3) Take the battery out and wait 5 seconds or so and put it back in 4) Charge the battery while the phone is off 5) When the charge is 100%, take the charger off then charge again to get 100% again 6) Turn on your phone and enjoy your new battery