I understand correctly that the Ample Power SAR-V3
may be used with a freestanding generator driving a
common automotive alternator (or two of them) or may
be used to turn any vehicle into a 12VDC generator
to keep a battery bank charged.

$449. is a lot of money but enabling a car whose motor
one already pays to maintain to do double-duty as a
generator may be cost-justifiable after the first storm
takes out the grid - or your off-grid sources of energy
are rendered inadequate due to equipment failure or
severe weather.