12 Volt Connection to RV House System

AC200Max here.

What is the best way to connect my and power the 12 volt system in my trailer. I don’t want to plug the 110v/30amp plug into the AC200. In an ideal world I would like to make the AC200 in parallel to my house batteries - essentially adding the AC200 capacity to my existing capacity.

Can this be done, should it be done, what are the alternatives?

The best way is to connect your RV cord to your AC200 MAX 30 amp RV socket and power the RV with the RV internal power converter / battery charger switched off. If you want to use the AC, use the AC200 if you want to use primarily your RV 12 volt batteries switch off your AC200 and use your batteries. That is the best way.

This is becoming a common AC200Max topic in other venues. Since it is common to want to use both AC and DC without constantly throwing a switch could I hook up the RV cord AND also wire the 12VDC output directly to the 12V fuse box? My RV is very small and with all DC on it would probably not get above the 30A limit on the DC output. That way I could switch off the house battery/converter battery charger when using the Bluetti, but have those available when on the road and needing to power the fridge electronics. Ideally I’d get rid of the house system completely.

That should not be a problem as long as you can isolate your RV batteries from your AC200 Max batteries with a switch. Do be prepared to switch your AC200Max off when not needing power to avoid the drain you will see when having the AC200 on, the regulated DC power activated but not having any loads operating. Before I did any of that, I would connect an extension cord to my RV shore power cord and connect it to your AC200 AC power outlet and try running the RV just as you would by being plugged into shore power. You would probably want to be able to switch off your coach batteries so they are not being charged via your on board RV power converter.

You will probably see a bunch of comments following stating that you need to go directly from DC to DC and it will be much more “efficient”. These statements usually do not take into consideration how much power it takes from the AC200Max batteries to generate a high amperage regulated DC output. In actual use there is not much difference. By connecting to your RV shore power cord as an experient, you will have losses incurred with your on board RV 120 VAC to 12 VDC converter but that can be overcome by connecting your RV DC circuits directly to the 12 VDC 200Max regulated DC output. If the straight plug in connection to 120VAC from the 200Max works but you would like somewhat longer batter life, then the next step would be a direct connection to your RV 12 volt circuits and bypassing your built in 12 volt power converter / battery charger

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Thanks SB,
I sent my AC200Max back for repair so it will be a few weeks before I can try that experiment.
I agree that having a switch to isolate my house system from the AC200Max would be a good idea. And from what you suggest I take it that I should be able to (with proper cables) hook up the AC200 DC output directly to the fuse box?

No actually I suggested that you first try using your AC 200 max with simply the AC outlet and see what you think before going down the route of trying to connect direct to the DC.

Understood. Will do.