I discovered something that drastically improved my battery performance even with it sync on all day. If your rooted get the CPU master pro app, and under profiles enable the screen off profile and set the max cpu freq to 918, or lower if you want your battery to be better, i found that 918 keeps me charged all day though, it will depend on how much you use your phone cause you'll only be saving battery when its not in use, if you use your phone alot then just go to the main profile and set it to around 1200mhz
Edit: I'm using RezRom1.6
Edit: I'm using RezRom1.6