I was doing an audit of how much AC each appliance used at my home. I bought a Kill-a-watt meter to do the audit. When I came to my plugged in RV, it used 5kw per day. In So. Calif. that is $.75 per day. Upon further investigation, I found the frig was using over 4kw per day. And the inverter was using the remainder. My 21 cu ft frig in my house uses 2.1 kw and my 14 cu ft freezer uses 1.6kw/ day.
1994 27sl Alpenlite with many mods, 2001 Dodge Cummins 2x4 3.54 Auto trans built shift kit and 2nd gear lock up mod. Mojave Green billet, triple disc low stall torque converter. Gauges and raptor 3/8inch fuel system. 12.5 mpg avg
I would leave the refrigerator off when not in use. THey are expensive to run it when not getting ready to go camping. Like stated above, 4.8 KW a day is not unusual. Your home electric refrigerator is much more energy efficient.
The problem is that when boondocking, it is nearly impossible to beat the low wattage used by a propane refrigerator on gas. They only use about 50 watts a day when on gas.
If you unplug the inverter for a long time, expect the batteries to go dead in about a week. The propane and carbon monoxide leak detectors use about 1.6 amp hours per hour, and will use up 35 - 40 AH per day, or 220 in a week.