I have a year old samsung galaxy 3. The battery is draining like mad. It was at 100% at 7:30am and now at 1pm I had to plug it in because the battery was at 10%. I have done two factory resets in the past two days to get rid of any bugs. I have run virus scans, no concerns. But I have a battery use app that shows the screen taking 80% of the battery. I have backlighting turned down as low as possible, backlight turning off in 1.5 seconds. I don't use my phone much. This morning I set it aside for 2 hours with all background apps off and it dropped 35% in battery. My phone battery monitor is showing Android system is using 25%. Help me... how do I fix this?