I have the same problem on a Dell 7537, the battery is holding solid 5 hrs of work, when I shut it down with regular -> Start -> rclick -> shutdown it seems like it's shutting down but in the morning I try to turn it on -> it cannot because it doesn't have enough power even for that.
For me W10 has been a disaster, graphics don't work as expected, this shutdown problem makes my laptop almost unusable. And the worst is that I am afraid that if I try to go back to W8.1 it will break the OS altogether and render my laptop unusable. I will try to roll back today and sure as hell will stay away from W10 for the rest of this lappy's lifetime.
I posted this yesterday but had problems posting. It finally did post but had a double post in the same post if that makes sense. Tried to edit it but deleted it instead by accident. Anyway here is what I had posted that might help you guys out.
There is a post a tomsguide.com, search for "Laptop Battery Drains to 0% while Powered Off (Shutdown)" and you will find it. Basically the reason windows 10 doesn't completely shut down and drains battery while shut down or hibernated is because of a problem with the 11.x.x.x version of the Intel Management Engine Interface. If you downgrade to 9.x.x.x it will fix it completely. 10.x.x.x might fix it as well but do not know. My Lenovo Y50 did the same exact thing, after a day or 2 the battery would be completely drained while shut down or hibernated. This cured mine and it drains none while shut down or hibernated.