Battery Tender's .........
Some PO must have added those due to bad information. Those batteryMinders are NOT OEM. WRV manufactured 2005 Alpine coaches with multistage inverter/chargers. You should have an Onan, Zantrex or Magnum inverter/charger, if as the OP said he has a SCP (System Control Panel), it is most likely a Zantrex. It could be that the charger portion is not working and the PO opted for the less expensive solution of 2 BatteryMinders, one each for the chassis and the house battery banks. With a properly operating modern inverter/charger there is no reason to add these aftermarket devices, the inverter/chargers have multistage chargers built in.
My suggestion, since you obviously need 120 volt power to operate the BatteryMinders, get the Inverter/Charger working. I often run my 2005 with adapters (50 to 30 and 30 to 15) on a 20 amp extension cord while we have the coach at our house for loading prior to departing on a trip. BTW we have a residential refer turned on (not the initial cooling, just maintaining while we pack the Coach, we cooled it down before we left storage where we have 50 amp service.
One other piece of advise, when you post, carefully look at any replies you get. WRV did some strange things over the years. Be sure you do not get lead astray by some other brand owners. Old Scout and Wolfe10 are previous Alpine owners that will give you information applicable to Alpines. Also watch what year the posts are talking about, WRV drastically changed the design in 2004 (and a couple of 2003ís) then again after 2005 there were less severe changes to the coach. In particular in 2004 the inverter/charger system changed the VMM controlled which battery bank is charged. You will also charge the battery banks while driving with the inverter again controlled by the VMM.
Dave, Bobbi and Fenway
2005 38' FDTS Alpine Limited, 2016 Jeep Grand Cherokee Limited
Lake Wales, FL