Battery Drains While Shutdown

I have a surface pro 4 and noticed that when shut down completely, the battery is still draining.  At first I just thought I forgot to shut down and put it into sleep, but after a few times of this, where I would not use it for a week or two and finding it dead, I realized there was an issue.  After some research, I realized there was a setting called "Fast Startup". I turned this off and noticed an improvement (although I think there was still a bit of a drain).  Now after the most recent Windows update, I noticed the problem more. Turns out the setting was back on, and I turned it off.  Yet, after doing so, I am seeing a battery drain of 10% within 24 hours of being shut down.  I don't use this every day, so is going to be an issue of opening up a dead surface that needs to be charged because I haven't used it in a week.  Is anyone noticing this problem, and have any recommendations?  Thanks.

NOTE:  On the  19th of the month I performed a complete Windows install (erasing my data files).  From 19 & 20 May, no apps, and no Office 365 was installed.  Nothing except Windows and all the updates.  I experienced a battery drain overnight on the 19th and 20th and each night I still experience a battery drain.  Below is the link to the battery report:     

https://1drv.ms/f/s!AsnLnheTLO-RgZIX6HWJJ1NgLGwa7A

Hello adarrow2,

We appreciate your response. Were you able to run a battery report - sleep study? If you haven't, we suggest that you try these steps:

Step 1: On the Search bar/Cortana, type 'cmd' to search for the Command Prompt then press and hold or right-click and select 'Run as administrator'.

Step 2: On the Command Prompt, type 'powercfg sleepstudy' and wait for the result.

Step 3: Follow and open the file location of the said report. (It will appear as 'sleepstudy-report.html')

Step 4: Once you open the report, kindly send the screenshots of the recent usage and at least one week of the report.

    *You may also upload the HTML file using OneDrive then share the link.

We'll be waiting for your response.

i did a complete win 10 reinstall including wiping my hard drive.  With ONLY win 10 AND The latest April 2018updates installed, there was STILL a battery loss.  No other programs were installed, not even Office 365 and yet two nights in a row, I experienced a battery loss at night during a complete shutdown.  Nor did I make any changes to any of the win 10 default settings.  please advise.

This is the answer:

https://answers.microsoft.com/en-us/surface/forum/surflaptop-surfperf/how-do-i-disable-connected-standby-on-my-surface/3404fcdf-6f68-4168-b40a-9126ef657879

Navigate through the registry by expanding these Keysets: HKLM > System > CurrentControlSet > Control > Power > CsEnabled. Change the value from 1 to 0 and restart.

HKLM\System\CurrentControlSet\Control\Power\CsEnabled (1->0) (change from 1 to 0 and restart)