My Lance 850 came with 2 Interstate deep cycle batteries, that said, I conserve power in a few ways...
At the campsite, I only use 2 of the jacks to stabilize the camper. I found 2 is enough. I always leave the truck idling when I am lowering or raising the jacks. Along with the furnace, the jacks are a big power consumer.
I never run the fridge on 12v. My 850 has a switch to disable 12v fridge operation, so it cannot be inadvertently put into the 12v mode. I either leave the fridge off or run the fridge on propane while driving.
Our Lance came with 1 85W solar panel. I am going to add at least one more to extend our dry camping stay without having to idle the engine or drive to bring up the batteries. Our Lance did not come with a generator, and I don't plan to buy one.