Default [Q] AT &TLG Optimus G E970 battry drain

Hello,
i am facing problem that my Phone (LG -Optimums E790) battery discharging very fast, i fully charges (100%) my phone at night and switch off it, in morning when i turning on it, the battery status was 63%, its mean 37% percent battery is discharge on switch off position. when i uses any application like browsing, game etc, battery continuously discharge, hardly 40 to 50 Minutes, battery was fully discharge

Please guide me for solution