[goodellj]

Maybe the previous owner installed a cutoff switch for the battery? Could the RV storage guy be mistaken about his description? I can't imagine why anyone would install a dedicated cutoff switch just for the Level-Up system.
If a battery cutoff switch broke, the solution would be to disconnect the terminals battery terminals. Or remove the battery, bring it home, and put it on a trickle charger. Or recharge the battery. A new battery may not be needed.