I need to investigate this a bit further, but my company's 30 amp connected Chevy Volt charger will only seem to charge my S at 15 amps with the J1772 to Model S adapter. It has been suggested that the charger may be "hardwired" to limit the charge to the max the Volt can handle. Not sure what the Fisker on-board charger can handle, but a Fisker-specific EVSE may have a similar limitation.