Bad S4 Battery Life. Help!

Hi, I am new to the S4, currently my battery life is quite bad, I am attaching a couple of screenshots so that you can get a better idea of whats happening with my phone.

Here is a list of items that are on:
Mobile Data
Sync ( Google account only )
Brightness ( Auto )

The problem I have is that I have heard a lot of people say they get 3-4 hours of screen time, as you can see from the image below, I have only had 38 minutes of screen time, one thing I will add is that my screen gets warm when I am using it ( you can feel its warm/hot when you touch it ), is this normal?

Any help will be greatly appreciated.