surface book battery drain while shut down

I am experiencing the same issue on my 3rd SB. The two before mine had many other issues before I got this one, including the battery drain. My battery life while on is pretty good with my 3rd SB, but it has issues when completely shut off. I posted this in the other battery problems forum, and I will post this here because it might be relevant, especially my last test:

"I am going to run some tests as to why my battery drains even when completely shut down. I have this feeling it's not turning off completely, which I find bizarre. These are the tests I am going to run in order:

1. Disable Windows Hello
2. Disable Fast Boot
3. Turn off WiFi or turn on Airplane mode before shutdown
4. Downgrade Intel Management Engine to version 9.x.x.x, if the SB allows me (My research found that those who upgraded to Windows 10 found that the IME version 11 drains the battery even when completely shut off; however, I don't know how instrumental IME is for SB. I believe it shouldn't affect it at all since it's used for remote desktops in a business setting)."

Man, that is SO MUCH to do before shutting down. Almost not worth it. Personally, I like to keep all that stuff 'as is' and just enabled Battery Saver and made sure screen brightness was at 'suggested.' I'm currently getting around 8 hours of everyday use with those settings. I think to make it less of a hassle it has been worth it to keep those features enabled. I didn't buy this laptop to keep it completely shut off and so useless I can't use it.

Well I am running each step individually first. I want to see how much battery life drains overnight/during the day and compare my findings. I have a feeling the first three steps won't do much, but I am hoping the last one fixes it.

Here is the link where I found info on step 4 of my tests: http://www.tomsguide.com/answers/id-2324931/laptop-battery-drains-powered-shutdown.html. For those who upgraded to Windows 10, IME is definitely the culprit. I wonder if the SB is affected too.

Other than the battery drain while completely off, I get incredible battery life with my 3rd SB - about 10% drain in one hour, so almost 10 hours of battery life. However, I have run into an issue of the SB not charging to 100%. It says it's completely charged when plugged in but when I take out the plug the base battery says 97%. Really weird and don't know what to make of it. Hopefully it will be fixed after a few more cycles.

Well I am running each step individually first. I want to see how much battery life drains overnight/during the day and compare my findings. I have a feeling the first three steps won't do much, but I am hoping the last one fixes it.

Here is the link where I found info on step 4 of my tests: http://www.tomsguide.com/answers/id-2324931/laptop-battery-drains-powered-shutdown.html. For those who upgraded to Windows 10, IME is definitely the culprit. I wonder if the SB is affected too.

Other than the battery drain while completely off, I get incredible battery life with my 3rd SB - about 10% drain in one hour, so almost 10 hours of battery life. However, I have run into an issue of the SB not charging to 100%. It says it's completely charged when plugged in but when I take out the plug the base battery says 97%. Really weird and don't know what to make of it. Hopefully it will be fixed after a few more cycles.

It takes several battery cycles for the battery program to be calibrated to your battery.  This from experience.  In the beginning it can be wildly inaccurate.

Thanks for that link, TaylorTeske! Very insightful!

Looks like FastStart was the issue in that case, I wonder if that is the big issue we are all dealing with when our SB's drain while completely off. Hrm...