it would greatly depend on the card and system. some contactors are straight voltage and some have a higher pull in voltage then a less "holding" voltage. ALSO not all ev100 systems can be changed voltage, and a far more common change is between 36 and 48 volts, and unless the system and card was 24 volts to start with, it may not be programmable for a 24 volt system.
EV100 has a system that does not allow the unit to send a signal to close the traction controls unless the correct order is followed in the start up (key and seat first, then direction, then accel.) and unless the proper inputs happen at the proper order then you will not drive.