This is quite normal for smartphone nowadays.

Use my method mentioned above, charge phone until 100% and unplug from power supply, then leave it in sleep mode for 2-3 hours. (DON'T turn on screen or use the phone at all during sleep mode)
After 2-3 hours, please screen capture on battery status something like this (if activities more than 1 page, scoll down and screen capture activities below):-
http://i1248.photobucket.com/albums/hh493/...zpsa618b7cc.png
From battery status screen, you know which activity drain most of battery. For my case, you can see after 2 hours+ in sleep mode, the battery drain about 2%. This means battery and firmware work fine and normal, so if battery drain fast is purely from usage pattern.   

Please screen capture your phone firmware too like this:-
http://i1248.photobucket.com/albums/hh493/...zpsec00f301.png

You need provide more information before members here can provide more appropriate solution. Battery drain very depend on your usage pattern. If you turn on screen every 5 min, automatic upload data at background through WIFI/3G, play HD game, etc.. All these activities will drain your battery faster.