The iphone 5 battery drains in 2-3 hours after full recharge.

The battery for my iPhone 5 would last atleast from 7am to 7pm when I initially got the phone. Since the last 3-4 days the battery completely drains off in 3-4 hours after full charge despite the fact that the phone is not being used. Have tried all the solutions circulating on the web including "reset all settings', turning location service off, turning off the active background applications. Any other recommendations??