Android system battery drain

Hi all,
I have a big problem with my tablet (lg gpad 8 v480 with lollipop 5.02) sometimes the android system and android os runs when tablet sleeping and drains my battery...
I attached 2 screenshots to saw the problem. I cant find any solution.

Any ideas?

Thank you in advance!

i.imgur.com/kVvJUmX.png?1
i.imgur.com/LKBDqRy.png?1