Ours came with solar which is used only for the batteries. It does seem to help keep them charged when we boondock. How much? I really don't know since we've always had the solar. I run the genny in the mornings just to top them off, but I usually don't have to leave the genny on very long. We use the DISH and TV off the inverter including lights and run the furnace in the mornings. Sorry I can't help you more....
02 Fleetwood Discovery 37U, 330 Cat pulling a 2006 diesel Liberty..or..2011 4dr Wrangler..or..20' Lund Salmon/Halibut Hunter