Tony,
I have the same Magnum inverter/converter and it will put 100a into my 6-6v Full River AGM house batteries. After a normal evening of TV-Internet X2 lights and coffee maker it will be tapered from 102a to 40a in a 30 minutes run of the Onan QD 7500 while coffee maker and DW's Latte maker run. From there on the solar system finished up the charge. The AGM batteries might be fine with adding the additional 80a but If you have flooded lead acid house batteries they "might" not like that much charge. I'm not sure. It probably depends on how many batteries you have. My Magnum is plenty for my 6.