Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. Today he discusses a battery disconnect switch and whether it should be on or off during the RV’s storage.
Dear Dave,
My 2021 Entegra Odyssey 30Z has a spring-loaded master power switch on the wall just inside the door. This switch effectively kills all 12v power in the coach. When in storage, and plugged into 20-amp maintainer shore power, should this master switch be on or off to allow the batteries to be charged through the onboard converter? —Timothy
Dear Timothy,
The battery disconnect switch on your Entegra will shut off access to your house deep cycle batteries by the converter. However, the LP leak detector is typically bypassed and will drain the batteries during storage. With the batteries not being charged/maintained, getting to lower voltage will create sulfation and also they could freeze in low temperatures.
Leave battery switch on but shut off circuit breakers
I would suggest leaving the battery switch on but shutting off the circuit breakers in the distribution center so no “gremlins” can occur. Since you are plugging into a 20-amp source, it is important that nothing else is on as the converter will typically draw 8-9 amps. You don’t want to overload the circuit. Also, make sure the source you are plugging into is a dedicated outlet, not ganged to others in the garage.
Leave the main circuit breaker on as well as the one for the converter, if applicable. Depending on your type of converter, it should run at 13.6 volts while charging the battery, then drop off to 13.2 volts as a maintenance charge once the batteries reach fully charged 12.6 volts. At 12.6 volts, batteries will not accept a charge and will be in a state of maintenance. This is assuming you have lead-acid batteries.
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I don’t understand your theory about shutting off the circuit breakers as they are 120V circuits and the question was about the 12V battery disconnect.
Bob,
If you have the unit plugged into shoreline power, especially only 20 amps, there will be power going to the distribution center. Shutting off the other circuit breakers ensures nothing else is drawing power except the converter/charger.
I installed a “knife” type battery disconnect switch on my house and engine batteries so they are totally disconnected from any “gremlin” parasitic power draws. Both sets of batteries are directly connected to separate solar powered trickle chargers mounted on my dashboard where they are exposed to the morning and noon sun every day. Since I set this up I have had absolutely no issues with dead batteries.