Battery drain extremely fast

[N_Pboeuf]

So earlier this year I got a dell venue 8 7000 it is a great tablet and I really loved it the first couple of months I had it, it still is a great tablet and I would still love it but recently the battery started draining fast. Like really fast, I would charge the tablet all the way then turn the tablet off and an hour or two later I would come back and the battery would be completely drained. I don't know whats causing it but I'm pretty positive it isn't just something in the settings or an app that's making the battery drain so quickly. Is there any way to fix this?

 

[N4Newbie]

Well, for starters, go to Settings -> Battery and see what the biggest power guzzlers are...

 

[N_Pboeuf]

It says that system OS is taking up 86% of the battery drain.