Do I need a Solar disconnect ?

[Skater]

There have been times when I've wanted to disconnect the solar system, such as to help isolate issues, test batteries without solar power interfering, etc. It's pretty rare, though, so I haven't gotten around to installing a switch. I'd definitely do it if I were doing a new installation, though.

[dkottum]

I don't like the idea of a solar disconnect because interruptions in the wire add a bit of resistance and are subject to corrosion and more resistance over time. I suppose if the connections were soldered it would be better.

Idroba, thanks for thinking this through. It's all working well, however they wired it. Battery Disconnect in STORE, no external power, then there is correctly no power to the 12 vdc equipment (except propane detector and brake switch).

A cautionary note: When you break camp and head down the road, be sure to return the Battery Disconnect to USE to keep your refrigerator running.

[lewster]

Originally Posted by dkottum

I don't like the idea of a solar disconnect because interruptions in the wire add a bit of resistance and are subject to corrosion and more resistance over time. I suppose if the connections were soldered it would be better.

Idroba, thanks for thinking this through. It's all working well, however they wired it. Battery Disconnect in STORE, no external power, then there is correctly no power to the 12 vdc equipment (except propane detector and brake switch).

A cautionary note: When you break camp and head down the road, be sure to return the Battery Disconnect to USE to keep your refrigerator running.

Doug,

The disconnect will have virtually no effect on voltage drop 'IF' you use the proper gauge cable, the right end connectors, run your solar connections directly to the batteries and place the switch in the right spot. You can't use solder on an airplane or boat, and IMPO, you shouldn't use it on an RV.....ANY RV either.

Dissimilar metals in the solder, brass connectors and terminal strips/busbars will eventually cause electrolytic corrosion. I see it every day, especially on open ended battery terminals where the corrosion runs 6-8" back up the cables. Keep it simple and crimp all of your DC connections with the proper cable ends, heat shrink and crimping tools.

[dkottum]

Lew, back when I was an electrician on Navy aircraft we used soldered connections frequently, especially on Canon plugs that joined wire bundles and then sealed them with potting compound. Quite a salt air environment.

Corrosion could be a problem in soldered and crimped connections, that's why I prefer to avoid cutting and reconnecting a wire if unnecessary, especially in low voltage circuits.

[nwclassic]

We use both the factory disconnect and a cutoff switch for our solar panels. A gauge can tell battery volts (or charge voltage of panels or converter), or amps + or -. We never allow panel cutoff to be on when AC is plugged in (nor traveling if batteries are full… truck alternator and small cable would not deliver much to trailer, but we have no way to monitor it).
An additional benefit of the cutoff reveals itself when diagnosing problems… no need to disconnect/reconnect.
Much easier to to it all at initial install. Good luck.