Residential Fridge Batteries - How many??

You can do it with two, but personally I think you should have four minimum. Coaches are changing. Most All Electric coaches use six to eight batteries. When many of us were adding the Samsung residential refer a few years ago, most did well on four batteries, since the coaches were not technically all electric (propane water heaters and stoves).

You also have to consider what type of camping you'll be doing, generator availability and do you like to do things like watch TV in the evenings when dry camping.