I had put my 36ck2 in storage last may and when I went to get it out in Sept, nothing worked either. However my converter had failed. It's not always the batteries.
2018 Cedar Creek 36CK2 (40.5ft)
TST Cap System (Tire Monitoring)
2021 Chevy 3500HD Crew Cab 4X4 DRW Duramax (replaced 2015 Chevy 2500HD Crew Cab 4X4 Duramax)
Curt A25 5th Wheel Hitch (replaced Demco 18K Auto-slide)