Microsoft's new Surface 3 features USB charging which is a great addition to the tablet as it does away with the proprietary connectors of the past. So the question becomes what happens if you plug the Surface 3's USB 3.0 port into the charging port that is micro USB?
In the pursuit of leaving no stone unturned and possibly burning down my house, I created the loop and the results were a bit amusing.
When you create the connection, the Surface 3 acts as if it is plugged in. The icon in the taskbar switches to the charging icon and the device goes into the power mode as if it was plugged into the wall (brightness 100%).
You can take a look at the video above that I recorded for a quick and dirty view of the process in action.
After a few minutes, Windows will say 'Plugged in but not charging' which means that the device is smart enough to not create a loop; my house is safe for now. At first I did think the battery was draining a bit faster than normal but I think that might have been placebo.