android system killing battery

my phone gives me 6 hours of sot on stock rom, but only 3.5 on cm11 snapshot m12.
Android system is consuming so much MORE than the screen, almost 40% of the whole charge from 100% to 1%,and the battery specs says "Android system" is active for 14 to 18 hours, sometimes more than 24 hours, which leads to lower and lower sot. does anybody know how to solve this problem? I've tried enabling /disabling system services with no result

Quick charger Killing My Battery

I have been using quick charger to charger my N6 since I got this phone in 12/2014. I had no problem until recently my phone will power off itself when its battery gets to 15%. Before, 15%of better life will lasts me another 15-30 mins. I charges 2-3 times a day using quick charger and I think it's killing the battery!!! Anyone had similar issue?

Free memory and avoid killing some specific apps

Hello,

I was curious to know if as on MIUI rom you where able to kill all apps except some which you lock ?

Looked a bit everywhere in Lollipop but i haven't found it.

The same for clearing the memory.

Any help is highly appreciated.