Disable Smart Cover/Lock

Hello, I want to disable the function that shutdown the screen when the cover of the phone is on the screen and that wake up screen when is not. I think it drain battery life so much.
Then I unplugged the phone at 7:10 am at 100% and at 9:00 am there are only 70% ... It is normal ? How much time you can go with 100% battery on your Redmi Note 3 Pro ? My girlfriend have a Redmi 3 Pro (not the note) and after 9-10 hours there are yet 60% :eek:

Why my Redmi Note 3 Pro drained the battery life ??

Sorry for my poor english. I'm french ...

Edit : I forgetted to say that my phone is currently on CyanogenMod 13 UNOFFICIAL by jackdepp with support of fingerprint.
I use this version because the official nightly CM does not support the fingerprint (there are not the menu).

EDIT 2 : I use Gsam for check battery drain and it say that :
CyanogenMod system : 41,6%
Kernel : 19,6%
Google PlayStore : 10,8%
System Interface : 7,4%
Google Services : 3.3%
System(adsprpcd) : 3.0% :eek:
....
Thanks

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