Short iPhone 4S battery life?

So I got a new 64GB black iPhone 4S. I really like it and kept it on iOS 7.1.2. The battery seemed to be getting low quickly, definitely quicker than my iPod Touch 4th generation. I then sent my iPhone to have its battery replaced. I know it was replaced for sure because the person who did it sent the original battery back with the iPhone. I sometimes run a VPN and an ad blocker in the background, but I did that with my iPod Touch. I turned reduce motion parallax on and Bluetooth off, along with some other settings that are supposed to save battery life. It doesn't seem to make a difference. Could any of you guys please help me out?

Ios 7 drains battery more quickly because of the more color and functions. (your ipod 4 isn't capable of getting ios 7 so your not use to the faster draining)

I have to charge my iPhone each day.