Do you have alot of apps running in background? Tap home key 2 times and there's a list across screen with icons you can deselect them by hold on one and they wiggle touch the minus button and it will deactivate them untill you use them again. Do you have the phone dim after so many seconds or minutes? Is the screen bright all time? Do you go on the Internet or watch video on phone?
These things can affect the hrs of use.
My husband gets 1 day or so. I get almost a day but now my phone gets. When my phone gets very hot I loose lots of battery.