What is going on with my iphone 5 battery?

I have everything that can be off turned off.
Still my battery life is only about 5 hours.
Is there anything else I can do?

Rechargeable batteries are known to decrease their levels of charge by developing what is called a "memory." The best thing to do is to let the battery completely drain, and then fully charge it.

The battery is probably burnt out which means it's just become dysfunctional. I had that same problem when I had my iphone 5 I would charge it 100 percent and just keep it in my pocket all day in less then 4 hours after I unplugged it it would already be a 30 percent when I wouldn't even use it. What I did it is I went to the Apple store and that's where they told me that my battery was burnt out they said it happens in a lot of cases when you plug and unplug it multiple times while charging which is what I did but they also told me there are numerous reasons for it. I don't remember if I had insurance there any type of warranty but the Apple Store change my battery for free. So you might want to go check it out. Hope it helps good luck.