Your year Model has an Inverter/Charger. Your Coach battery disconnect does NOT turn the batteries OFF from the Inverter/Charger. While plugged into 120 shore the Inverter/Charger will be trickle charging the coach batteries. Your year model, Monaco may NOT have optioned the Bi directional relay that would also trickle charge the Chassis batteries. Regardless, I would install a battery maintainer on the chassis for the months you plan to store. So, disconnect the Coach battery by the ON/OFF switch and your coach batteries will be charged and maintained. Use the link to see just one type of battery maintainer. Doug
https://www.batterytender.com/Battery-Tender-Junior-12V-0-75A