iPhone 4s batter life saving

Hi,

I have an iPhone 4s with the latest version of iOS 8.3. My battery life has been draining very quickly it wouldn't even last one day. I have background apps refresh disabled & location services enabled. I also have the Battery Doctor app on my iPhone 4s which it tells me to leave the app running in the background while charging my phone. But the app still not works no improvement so what can i do? I really need location services on because i'm using Find My Friends to locate where my friends are and also my contacts to locate where i am. And i would hate to turn of location services if you can help me that would be great. Feel free to reply back to this thread ASAP thanks!