Battery voltage drops!!!

I have a new Thor Tuscany (yes, I know!) all electric motor home. It came with 4 very poor 56# GC2's. I replaced those and added two more (6 total GC2's (@ 67# each) @ 230 AHrs from Samsclub) and now I'm lucky to get by for 24 hours. Depends on how many cups of tea/coffee we boil on the Induction range top. It's something like 80 amps scaled down to a power of 3/5 but only for 6-8 minutes. I should have 3x230 AHrs now but the battery voltage stays below 12 most of the time. Seems to only take a short time for it to be below 12V. Yes, I have a 100 amp converter so with the generator running I get a measured 105 amps going into the battery bank. My current probe shows the 105 amps nearly evenly split on the three battery series pairs. The Cummins alternator is connected with 2/0 wire so I do see good charging going down the road. I see about a 11 amp load (12V battery to inverter) from the 23 cu foot fridge. Not a good boondocking situation! Count on at least 3 hours of generator use a day! Have not figured out where all the power goes yet? Oh forgot, the fridge lights with all three doors open draw about 350 watts!