Iphone 5 serious battery draining issue..

My battery loses about 1% of charge about every 1-2 minutes of web-browsing! Even worse with gaming or any other online app.i tried everything including hard reboot without backup,turning off locations 3g wifi etc..still drains dramatically.is this an ios issue that will be fixed or does my iphone need te be replaced?this is ly third iphone and i never had a battery drain this fast.especially not one that is supposed to be superior to previous batteries.