There is also a effeciency factor. Your inverter loses about 10%.
So you might see 100watts of AC power required to generate 90 watts of DC.
I suggest one of these two methods.
Buy a energy meter, about $30. They are 110v, so you need to power your coach from a 20amp circuit.
Brand name is Kill A Watt meter
Also, look at your electric meter, without the coach, and then with. Just dont turn anything in the house on.
2014 40QBH Phaeton DP Cummins 380HP ISL, Freightliner XC, 2014 Jeep Trailhawk TOAD
Blue Ox Aventa tow bar, SMI Air Force One -South Orange County Ca.