How much can your inverter/charger put out when charging?
100 amps is abut 1500 Watts, given the losses you are pushing the max for the Honda. Many inverters you can "throttle" them either by adjusting battery size down or by setting another pramater or two.
Ground faults
The Honda has an OPEN GROUND.. Many have made a special "Bonding plug" basically it connects the WHITE (Silver screw) and Ground (Green screw) together.
I have not done this so can not comment.. When I have to do it I do it differntly, but .. Well. I've not had to do it.