When we had the Springdale, (equipped with one 12 volt GP 31 battery) with the battery cutoff switch in the "OFF" position, the battery would discharge in about 14 days. With the Cougar, (equipped with two 6 volt batteries) with the battery cutoff switch in the "OFF" position, the batteries will discharge in about 6 weeks.
Depending on what "parasitic" drains remain active when the battery cutoff switch is turned "OFF", in time, you will have a dead battery. The length of time depends on how your specific RV is wired as well as the condition of the battery. The only practical way to completely eliminate any parasitic drain is to remove the battery from the electrical circuit. You can do that by disconnecting one of the battery terminals from the battery or by installing a second battery cutoff device on either the positive or the negative battery terminal. Electrically isolating the battery from the trailer will serve the same function as removing the battery and taking it home with you. Either way, disconnecting one of the battery cables or installing a second cutoff should eliminate your dead battery problem.
2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS