Steve, you may be right about sticking with a 20 amp charger to be on the safe side. ? But, the interesting thing I have noticed when looking for relays is that even the ones rated for 30-40 amps only come with 12 gauge wires, some with only 14 gauge wire harnesses.? Why they don't use at least 10 gauge, I don't know!? My concern now is still re if connecting the relay to just any circuit when the ignition is on has the possibility of doing damage to sensitive electronics.
???? Bob
