I installed a pair of Sam's Club energizer GC2 6 volt golf cart batteries on my KZ 23cfk and have made it ten days dry camping, but this is being frugal.
Propane fridge/freezer, water pump, radio and minimal light usage, but 3 bunk end fans running while sleeping at night.
The factory battery meters installed are junk.
Having got into the electric golf cart money pit a couple of years ago, I have learned a bit about batteries.
My next mod will be to install a LED battery pack digital voltage meter. The state of charge of the battery/batteries is something you need to be aware of. Deep cycle batteries should not be taken below 50% charge, so for a 12 volt system, when the voltage reaches 12.10, it needs recharging. 12.73 volts is considered full charge for a 12 volt system at rest.