Two thoughts. First no, if you always have shore power you don't need a kilobuck of batteries. If you can get at 'em and feed 'em a bit of distilled a pair of standard lead acid flooded wet GC-2's is more than enough
or a group 31 (in Maintenance free or AGM)
However second thought
Digger O'Grady and his marvelous backhoe did a lovely job on one of the high voltage primary lines into the campground where I was camped.. I spend a couple days on generator/battery
Storms did the same at another CG
Three More had underground lines fail.. One while I was absent, that one was "Selected sites" so all you needed to move (About half a dozen sites including 2 of my favorites) another it was the main feeder to ALL the park, and another to about 1/3 the park. That all park one I did not have a generator (PUP days)
Heck, underground feeder took out power to the next building in my apartment complex a week ago tomorrow. 16 and a half hours
I have battery backup for SOME stuff here. .Not sure I could power the fridge for 16hours though.
