Who to believe?

OK a battery is cheap then, keep in mind if you leave a light on, or the switch for the white water pump, kiss a battery good-bye.
Just pay up for a good marine battery and be done with it.
Where we camp now has electric hook up, so I am not buying another battery to run the 12/120 lights etc.
Also a fridge will drain one, I think all camper should come with a a shut off switch when not in use.