[Carsmak]

Oh hell, now you went and did it. The hatch covering the abyss of inverter efficiency and sine wave purity has been opened. That discussion has been beaten to death on RV and solar living forums all over the internets. Same goes with the "choppy" nature of inverter sine waves & their effect on resistive and inductive loads.

SIX, I started busting up in the first 2 sentences of this write up by you. I always feel like I learn something by the time I'm finished reading your posts..

...... another thing not mentioned here is that while traveling, the propane flame 'can' blow out, depending on trailer / fridge design & winds encountered (cross-winds, etc.), which of course ends the propane cooling. No wind-worries on 12V, and I don't know of any reason to to use 12V on the road if your systems are functioning properly.

And I'm not sure I am remembering correctly, but it seems to me like there might have been auto-switching that moved from one source to another (e.g. when propane runs out or flame goes out) on one or more of the RVs I used???? Does that sound right to anyone?

Dnick, yes no wind no worries, and I would go as far as to say that if the 3-way refrigerator MFG, has instructions for operating while in motion, vs campground (shore power) vs off the grid camping, that's where I'd start.

When I was a kid, the first travel trailer my grandparents had a 3 way refrigerator and we ran it as OhSix suggests, problem was the pilot always blew out and was pretty worthless from Michigan to Florida (winter trips) or Michigan to Tennessee (summer trips) so what we needed was in coolers til camping in nice campgrounds for a week to 10 days with shore power, or overnight with propane cooling things while in rest areas or cheap $10 no connection spaces along the route. The 2nd trailer a much nicer 5th wheel, had I believe either a much more insulated/wind blocked setup or some kind of auto pilot/switching mechanics which we stocked it, once and left the coolers behind.