if u are looking for low battery drain then stay away from custom roms especially cm based roms.
not only they drain the battery fast because they are badly ported or whatever but also they are missing samsungs energy saver mode which does save alot of battery. (only enable cpu and u will never notice its on)
so if u really want to use a custom rom then atleast get a tw rom.
my best experience for best battery on my s2, s4 and note 3 is original stock rom with bloatware removed, energy saver mode on (cpu only) and xposed+xblast module.
Try to download Wakelock Detector from the Play Store and see the root that causes it. For example, the last time with stock rom, I have issues with Google Play Services with NIPcollector issues that keep on waking the phone without letting it to fall into deep sleep causing a huge battery drain. The solutions, Wakelock terminator, can be download in Play Store aswell. The free version of wakelock terminator only let you terminate 1 services which is just enough for my case. If you have more than one services causing lots of wakelock, consider getting the donate version.
Do use Greenify to hibernate unused apps aswell, it does really helps.