Sub-alternators were a specific kind of component found on starships. A starship, originally assigned to carry four Jedi from Coruscant to the Starlight Beacon space station in 232 BBY, had to be replaced by the Vessel transport of the Byne Guild due to a subalternator malfunction. Later, in 35 ABY, Poe Dameron caused both sub-alternators on the Millennium Falcon to fail during an instance of hyperspace skipping.