My battery is completely draining overnight?

Yep, I would remove the ABS main system relay to see if the drain stops, here is a guide and the location of the relay in the images below.

https://www.2carpros.com/articles/car-battery-dead-overnight

Check out the images (below). Please let us know what happens.

Hi, thank you for your answer. But now I have an additional question. I have a dual battery system. The main battery was just now fully charged while it was disconnected. However now the accessory battery is reading lower at 10.2 (it "was" reading the same as the other at 12.7) what is the reasoning for this? And is related to the previous issue that I questioned?

We now have fully charged my accessory battery and this is how the display looks after it was plugged in overnight. Is my battery in need to be replaced? And is that the cause for the rapid drain?

I don’t know why but the video could only be pasted via a link.
Added pictures below as well…

If the battery drains overnight while disconnected the battery is bad.