[tech]

u have that issue on older biuld dates even if ur on stock im on my 4 phone and biuld date is 1 13 09 and it doesent do that at all it last long time i can do email listen to music and still have full barrs 100 percent for like an hour and a half then it changes drops one varand im running stock rom leack version but it came like that whne i got my forth