HI Takoman,
I'm sorry for your experience on Surface 2. I see that you are having a on going issue with battery drainage and also an unregistered device. I'm glad that the community has been supportive and helpful so far. This is great.
I'll also suggest running the Hardware and Devices troubleshooter in Control Panel.
- Go to Control Panel
- Troubleshooting
- View all ( On the upper left Pane)
- Run the Hardware and Devices
If the issue still persists, the other option is to refresh the device. I see that you willing to take that route.
Have you tried refreshing your device yet? How did it go? Also, remember to install all available updates once you done the refresh.
Please let us know so we can dive into more troubleshooting and try to resolve this issue in the best way possible.
Thanks again for posting in the Microsoft community.
Cheers,