Thanks everyone, and I apologize for the numerous numerical and reference mistakes in my post. Gotta review it before posting. The "watts is watts" reply turned on the light bulb (pun intended) for understanding this massive amp draw when sourcing DC for an AC load. My batteries: 2 Interstate PowerFast Series 6V, PF-GC2-UTL. 107@75A, Ahr 208. Not sure what the 107@75A refers to but yes I have 208 Ahr to play with. So to protect batteries I should draw 1/3 then recharge. 208x.33=68 Ahr. My furnace draws around 10 amps so I can run it 6-7 hrs then it's recharge time. Is this correct understanding of my DC RV power?
My batteries as they stand will support my LED tv plugged into a 400 watt inverter for 2-3 hrs a nite, then recharge em with generator while brewing that all important pot of morning coffee. Final question if I may, I have a WF-9855 converter onboard, if I limit all RV draws how long would it take to recharge the battery bank with the 55 amp converter output? Thanks everyone who posted, learning so much from you folks!