My iP 5 has to be charged 3 times a day on most days. It's 17 months old. And during that time I have been a heavy user time wise. I don't play intense games much. It's mostly been forums, Facebook, Photoshop work, Words With Friends (with Wife) and a few other things. My Wife likes to FaceTime me all the time from her bedroom. That takes a lot of battery. If you're concerned about your battery's performance, take this test.
Write down your usage and standby time, press the sleep/wake button (or lock button, as some call it) to put the device to sleep, and set the device down for five minutes. When you come back, take note of the change in time. If your device is sleeping properly, then the Standby time should have increased by five minutes and your Usage time by <1 minute . If your Usage time rises by more than one minute, you have a drain problem. Something is keeping your device from sleeping properly, significantly shortening the time it will last.
Sent from my ancient but trustworthy iPhone 5