Sorry for the inconvenience.Samsung Galaxy S3 Tips: Maximizing Battery Life
Deleting your email account and then adding it on again will make the Samsung Galaxy S3 refresh its settings and help as well. If you sync your email then you may find it uses a lot of your battery. A better solution may be to change from automatically fetching mail frequently to getting it at intervals much further apart, say every 30 minutes.
If you have live wallpaper enabled then you might want to change it to a static one to get the most out of your battery. The same goes with using darker wallpapers and reducing the number of widgets on your home screens.
Turn off features such as Hotspot and GPS if you are not using them. Simultaneously delete apps that aren’t in use and remove any task managers or battery saver apps as the majority have been found to cause more harm than help.
Lower the brightness of the screen and avoid using the auto-brightness setting. You should also turn on the power saving mode feature.
I would also suggest you to have your phone/charging cable/battery checked at Sprint Service and Repair Store. www.sprint.com/storelocator