Download JuiceDefender – Battery saver for Android. Usually the battery lack more in background process, like GPS on for navigation, updating Facebook, refreshing Gmail etc. To restrict this background process the best battery saver I found so far is JuiceDefender.
It is the most popular battery saver, manage the background applications. It controls the most draining part like 3G/4G and Wi-Fi, You can control all the system option automatically from it. A must try battery saver for every android user.