led function for other variant?

 i really like the feature on the hovercar to have the led as battery indicator and show the board is on.  i am now trying to setup a nunchuk project.  it doesnt look like the nunchuk variant is supported on the sideboard.  is there an easy way to modify the config file to just use the led as battery indicator like on the hovercar variant and connect to my nunchuk flashed mainboard?