What I want to do is run my refrigerator with battery power when towing. I have a 8 cu ft Dometic refrigerator. I generally tow for 4 to 5 hours max. I have two 6V 210 AH batteries in series. I have a 2000W inverter. I will pre-cool the refrigerator prior to departure. I have a 190W solar panel to help charge the battery while towing and I tow mainly during the middle of the day. I don't know how much I can rely on the truck to assist with charging the RV batteries.

The Dometic manual says the control panel draws 3 amps which I assume is continuously. The AC heater draws 5 amps which I assume is intermittently. So worst case the refrigerator is drawing 8 amps/hour. For a 5 hour trip that would be 40 amp hours.

I'm not expert on batteries so I don't know if I can add the amp hours together for 420 AH or if I have 210 AH which means I would have 105 AH to use to power the refrigerator allowing discharge down to 50%.

It appears that I have sufficient battery power to run my refrigerator while towing. Am I missing something?