iPhone 5s Battery

Hi,

First time here. Glad about that. I bought my iPhone 5s two days ago and the battery life doesn't feel different with my iPhone 4s (used it for over 2 yrs, so thats understandable) - although i'm guilty of running some battery-sapping apps like instagram + chrome. But i still don't think i should be having a usage of: 6hours and Standby of 18hrs. is this normal or its a software issue with my phone. btw is use the new OS on my iPhone 5s but a lot of people have mentioned how the OS doesn't affect your battery life.

Thanks