Re: Just how bad a small 'frige is
Ah, but the upside is the 48 Volt system is every-so-slightly more efficient than 12 Volt.
And most inverters will run around 90% efficiency these days.
So the 1200 Watts hours is 1333 on the DC side, plus the 480 Watt hours of the inverter being always on (20 Watts per hour) = 1813 Watt hours. Divide by 48 Volts and you get roughly 38 Amp hours per day to run the 'frige.
Some caveats: the refrigerator's actual use will vary from day to day due to changes in ambient temperature and how often the door is opened; the current draw from the batteries is not fixed because of the Peukart Effect (more current as the battery goes down in Voltage - calculating it at system nominal gives an advantage as that should be the minimum Voltage seen); panels recharging during the day should take some of the load entirely, further reducing the battery draw (except on days when there is insufficient sunshine).
That's the reason for the fudge factors; adjust the numbers the right way and you get enough margin for error to make it work all the time.
Four 175 Watt panels, OB MX60, 232 Amp hrs, OB 3524, Honda eu2000.
Ohm's Law: Amps = Volts / Ohms
Power Formula: Watts = Volts * Amps