Battery life 2020 Jayco Precept 34g

Jay58 wrote:
What would one expect 2-6 volt batteries (225ah) wired for 12v to last with a 21 cup ft residential fridge.

No other significant use I would expect 24 to 48 hours before the inverter shut down from low voltage.

Solar will of course extend that time expectation. You will need more than 500 watts and at least 4 batteries to attempt continuous use. Lithium will make your solar more effective as it does not have the long absorption time of slow charging like lead-acid.