You can save battery life by taking the following steps. 1. Ask your phone what is using the largest percentages of power. (Settings » About phone » Battery use) If you ask Android what’s using what percentage of available battery power, it will tell you. The vast majority of the time the biggest power hog is the display. Save-Battery-Power-on-an-Android-Step-1    

  1. Tell the device to only use 2G networks. (Settings » Wireless controls » Mobile networks » Use only 2G networks) If you do not need access to high speed data, or there is no 3G or 4G network where you live, you can tell Android to only use 2G mobile networks. You will still have access to EDGE network data and WiFi if needed.

  2. Reduce the brightness of your display. (Settings » Sound & Display » Brightness) Most people can see an Android display quite well with the backlighting feature turned off. Move the slider all the way to the left, then try using the device that way. If you can’t see it well in that setting, move the slider to the right only as far as necessary to view the display comfortably. Alternatively, Auto brightness coupled with power saving mode (found on most Samsung, LG, Sony, and some Motorola devices) will conservatively adjust the display to the surroundings to only the brightness necessary.

  3. If your device has an AMOLED screen, always use a black background. AMOLED screens can reduce power usage sevenfold by displaying black instead of white or any other color. When searching on your phone you can also use Black Google Mobile at to get standard Google results (including images) all in black [3].

  4. Set your screen timeout to the shortest length possible. (Settings » Sound & display » Screen timeout) This setting tells the device to turn off the screen after the selected period of inactivity. The shorter the period, the less power your display will use. The setting options vary from phone to phone.

  5. Turn off the wireless feature when not needed. (Settings » Wireless controls » WiFi, or get the Wireless Settings free app) The wireless networking transmitter uses quite a bit of power. Even when the device is not connected to a network, it will continue to search for one on a regular basis.