Just a side note on your Dometic CFX cooler..I have seen countless reviews of all the portable compressor refer's seeing just how long they will run on battery power..
As an example,the CFX-50 will run about 60 hours on the 500 WH Jackery power station which is equal to a good group 24 battery at 50%..84 amp hours to watt hours is 1008wh but at 50%,which is he lowest you want to go with a 12V battery,it is 504wh or the same as a power station with 500 watt hours..
So in 60 hours of running the refer for the CFX refer alone,you would be out of juice or at 50% on that group 24 battery in alittle over two days...
I run my Engel refer on a stand alone battery with a volt readout and all the other stuff on other batteries...The refer alone draws more than people realize,depending on which model you get/temp and how often it is opened...Dometic public numbers are alittle deceiving compared to actual use..