Guys..
This is my 2 cents worth.
It's frustrating. I purchased my Surface Pro 4 in May 2017.
It was a new unit and I was excited with it. Soon enough I realized that there was a serious flaw with the Battery Drain. I began to check and the Q&A went back as far as 2014 as I can see. Could be further back though. Same Q&A. I also tried all those suggestions given. NOTHING seems to work. So I am totally disappointed. I'd probably just cut my losses and move on with another brand. Sadly this series is NOT a thumbs up for me.
But I must say that I am very pleased wit ALL the other features available. It's only the battery drain thing. I cannot predict when I will be left high and dry and that is not good.
Sad Customer.
Brian E.