Surface Book 2 battery drain whilst off

The Intel Magement Engine Interface (IMEI) can't be disabled for stability and eficiency purposes,. You solved your battery drain updating your firmware and shuting down your device using the shift key because you are telling to your OS to avoid the use of the fast boot and hybrid shutdown. 

Here is an image showing the block diagram of IMEI on a computer.

https://software.intel.com/content/www/us/en/develop/articles/getting-started-with-intel-active-management-technology-amt.html?wapkw=intel%20management%20engine%20interface

Actually it can be disabled. Some paranoid people have figured out how but you have to add a chip to the circuit so it's only applicable to desk tops or full size laptops. There's a YouTube video if you're interested.

Sorry for my bad english, the correct word is shouldn´t. 

The Intel Magement Engine Interface (IMEI) shouldn't be disabled for stability and eficiency purposes. You solved your battery drain updating your firmware and shuting down your device using the shift key because you are telling to your OS to avoid the use of the fast startup and hybrid shutdown. 

IMEI is needed to communicate the OS with the mother board, CPU and other peripherals like Intel vPRO.

If you don't want the fast startup option on your computer you can disable it by doing these:

• Right click on the battery icon on your taskbar.
• Select Energy options on the menu
• On the windows opened, select Choose what the power buttons do.
• Select Change settings that are currently unavailable.
• Click on Turn on fast startup (recommended)
• Save changes.

Hi Cesar! 

I'm happy to say that updating the drivers and pressing shift + shutdown has fixed the issue. I'm going to try, just for fun, not pressing shift tonight before shutting down. Thank you very much!!!!!  

Regardless, what I've highlighted above are the steps to avoid needing to press shift at shutdown every time? Will the bug still exist in hibernating (like my Surface has set after 3 hours of sleep to go into hibernation)?

Hi!, KentSpain85. I'm glad to read that.

This behavior isn´t a bug, is the result of the mechanism used to obtain a faster boot time. You can try comparing the startup time using hybrid shutdown or not using it.

Yes, the steps are to disable the fast startup feature that consumes battery while keeping data in RAM for faster startup. If you don't want to use shift key on every shutdown, you can try disabling the feature with these steps.

The surface devices has a feature called always on, **always connected or modern standby.**This feature maintain your surface ON while  is suspended with a little amount of processing power. The default configuration of these feature is to pass to hybernation state after the 5% of battery budget consumed or a time predefinied. You can see these transitions using the command powercfg /sleepstudy on powershell. This isn't a bug too.

There are resources to learn about modern standby.

https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby

https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-user-experiences

After months of toing and froing with Microsoft Support on this issue and after their level 1 & level 2 support doing exactly the same diagnosis on my device, they said I have two options. 

1. Escalating the issue to level 3 support.
2. Providing me a replacement device.

Replacement devices are refurbished devices but as the support consultant claimed it will come with 1 year warranty (my device warranty expires in few weeks), I opted for that option and I received the replacement today. I had to send my device to them before. However my Microsoft Account displays warranty until 16th July which is only 2 weeks extra warranty, so now I have to go back to them on it.

As for the battery performance, I have no idea yet. Will keep you posted.