Exterior Hydraulic Lift Control Panel Beeping

[fernsco]

2018 2120RL in storage with battery disconnected in the front compartment and by the switch in the utility compartment as ususal.
A beeping noise suddenly started today traced to the exterior control box for the hydraulic lifts and would not stop until I turned the battery switch back on in the utility compartment. First time this has happened so it's puzzling. For now I left the battery switch on but never had to do this before.

Thoughts?
Thanks,
Scott

[rohrmann]

Something on your 3120RL was still connected. There is no way you would have anything beeping if no power was there. The best way to stop all power from the batteries is to disconnect the ground cable that goes to the frame of the trailer from the negative terminal of that battery. No need to disconnect anything else.

[Carl n Susan]

Is the RV plugged in to 120V? The disconnect switch in the convenience center does not disconnect all 12V power. Specifically there is power to the hydraulic control unit along with other parasite draws (propane detector, etc.). These draws will deplete the battery over time. The beeping by the hydraulic system (and likely the propane detector) is an indicator of low voltage.

Turning on the disconnect switch in the convenience center does nothing if there is no shore power. But if there is shore power, the converter now has 120V and will start charging the battery with 12V which satisfies the low voltage warning from the hydraulic system.