If your charger works and your able to get the wheel to spin with it off the ground the controller is most likely good. When they fail they either stop working completely or go into runaway (full throttle).
Otherwise you will need 2 12v batteries wired in series to test it. Any larger size battery will work (over 4ah). Should be a matched pair.
Hugh
SDscooters
Otherwise you will need 2 12v batteries wired in series to test it. Any larger size battery will work (over 4ah). Should be a matched pair.
Hugh
SDscooters