Disconnect Switch Question

[Trout One]

Happy Fourth of July, folks!

A quick question about shore power before we head out for a few days. Could not find an answer in an arguably casual search but does the electrical disconnect ("salesman") switch just disconnect the battery so it doesn't drain while the trailer is not in use? Or does it disconnect the entire electrical system?

Difference being that if it disconnects the battery only, you could use shore power to run everything without overcharging the battery? If it disconnects everything, well, nothing works. In that event, you leave the switch on and shore power plugged in and don't stay anywhere too long...

Make sense? Thanks for the education.

[BobC]

From your owner's manual:

THE POWER CONVERTER
The power converter is the nerve center of the
12-volt DC and the 120-volt AC system.
• The power center will supply 12-volt
requirements when operating on 120 AC
volts.
• The onboard battery will gradually be brought
to a full charge and maintained by the 6-amp
battery charger as long as 120-volt power is
available.
• The propane leak detector and other 12-volt
components continually consume small
amounts of current even when switched
“OFF”. The trailer’s battery will fully
discharge within 72 hours if not recharged
during that period or if the power center is not
connected to a 120-volt AC source.
DISCONNECT THE BATTERY IF YOU
ARE NOT USING YOUR TRAILER.


I read this as the need to physically disconnect your battery to avoid a parasitic drain.

In any case, you don't need to worry about overcharging your battery. Your power converter is designed to go into float mode when the battery is fully charged.

To simplify disconnecting the battery when the trailer is not in use, I suggest installing a battery switch at the battery. I installed one of these on top of my battery box of my trailer:

https://www.amazon.com/Zoostliss-Bat...897892&sr=8-13

Contrary to what one might think, disconnect switches should be installed on the negative pole of the battery. You'll need a short battery cable to do this but make sure it's long enough to remove the cover from your battery box for access to the battery. I left one handle in the socket with a safety line and stored the second one onboard.

There are other switches that mount directly to the battery post but they require that you remove the cover to gain access.

[Trout One]

Thanks for the extra tip on the switch at the battery box! Good idea as yes, I will physically disconnect the battery when I get back from this trip for storage until the weather cools off around here.


And I appreciate the info about float mode as I've seen several posts warning about boiling the battery dry if shore power is connected for weeks/months at a time.


Short story, I'll just keep doing what I've been doing and quit overthinking things.



Bob

[BobC]

Originally Posted by Trout One

And I appreciate the info about float mode as I've seen several posts warning about boiling the battery dry if shore power is connected for weeks/months at a time.

Even with the converter's float mode, I wouldn't recommend staying connected for months at a time. A well-regulated solar panel is better than staying plugged into shore power. Your initial question implied that you were concerned about leaving it on while camping.

There's quite a bit of information online about this. Here's one example:

https://rvshare.com/blog/7-things-need-know-rv-battery/

[Wyatt]

Originally Posted by BobC

Even with the converter's float mode, I wouldn't recommend staying connected for months at a time. A well-regulated solar panel is better than staying plugged into shore power. Your initial question implied that you were concerned about leaving it on while camping.

There's quite a bit of information online about this. Here's one example:

https://rvshare.com/blog/7-things-need-know-rv-battery/

Hi Bob,

I read the article you referenced. He doesn’t mention power centers with three stage charging—the float charge being most important when connected 24/7 to shoreline power.

[BobC]

I'm no expert so I'm not going to say yea or nay. However, if left in float for an extended period of time, you'll still need to monitor your electrolyte levels. Personally mine are charged via solar while in storage.

[Morich]

It gets down to pretty simple with the newer charging system. as the voltage of the battery hears normal, the charger drops the output voltage. what makes a battery charge ror not is the difference in potential that we call voltage. when the potential from the charger matches the potential of the battery. there will be no current flow,except if there is a drain pulling power out of the battery and then the charger begins to replace it.It's always good to check the water in batteries but with the newer chargers, there is little worry about boiling that makes the water go down very much, so given the choices, I just leave the RV plugged in and do the water checks every few months. Since we parked in storage next to the house last fall, the batteries have not needed any topping off. I like to go out and do a look around every now and then just to check things like leaks, bugs and such anyway, so the batteries are not a big problem.
I mostly do that while I do the engine and generator runs.
How we each handle things like this depends on the situation we each have to deal with.

[Trout One]

Originally Posted by Morich

...It's always good to check the water in batteries but with the newer chargers, there is little worry about boiling that makes the water go down very much, so given the choices, I just leave the RV plugged in and do the water checks every few months. Since we parked in storage next to the house last fall, the batteries have not needed any topping off.

That's more the scenario I had in mind as that allows us to use the trailer as a guest bedroom when we're not on the road, since we park it on a pad beside our house as well. I was just curious if you could isolate the battery from shore power using the disconnect switch and just leave shore power plugged in and still have lights, etc.


Bob

[Wyatt]

Originally Posted by Trout One

That's more the scenario I had in mind as that allows us to use the trailer as a guest bedroom when we're not on the road, since we park it on a pad beside our house as well. I was just curious if you could isolate the battery from shore power using the disconnect switch and just leave shore power plugged in and still have lights, etc.


Bob

We do the same thing. Leave ours plugged into shoreline power 24/7. We do have a three stage charger though, that’s important.

Every once in awhile when I’m in the coach, I’ll turn on the ignition switch to the FIRST position, and then I’ll hear the power center start charging the engine battery as well. I monitor all of this with the Victron.