My Iphone would go dead on me way too soon so I looked into ways to improve battery life. I don't know what you have running all the time like email pushing, wi fi and bluetooth, along with all the other bullshit these phones have, but I turned a bunch of that stuff off and I can have my phone last a good 24 hours or more if all I am using is email, texting and phone. When you have all that other stuff running along with apps, games, siri and more, it is constantly looking for signals, locations, etc. which is a constant drain on the battery. I also lock it and turn the screen off when not in use.