You can access the battery charge settings for your Rok Box MC Mobile via the control center application, which is accessible from the taskbar in Windows, just to the left of your Windows clock:
Then, open the Battery Options as shown here:
Set your desired battery charge level. Maximum battery charge is the most common selection. If you wish to charge your battery to only a certain percentage when your MC Mobile is plugged-in, you may make that setting here.
Once you have done so, close the application to save your settings, and then reboot your PC.