I have a 2010 Cougar 276RLS with two 12 volt batteries that will discharge in two or three days if I am running the frig on gas. This is just setting with no other use such as lights, pump, slide etc...
The phantom draws plus fridge will draw at least 40 Ah in two days and 60 Ah in three days and probably more. If you have gp 24 batteries it would put you down about 62% SOC in three days. If your batteries are also a little weak . . .