Inverter Remote Switch Clarification

Been scratching my head over this one for a while with my cabin setup, so thought I'd throw it out here.

Running a Victron Multiplus-II 3000 and I've been trying to get the remote on/off wired up properly — partly for convenience, partly because I want to be able to kill the inverter from inside the cabin without tramping out to the battery shed in the dark.

From what I can piece together, the standard Multiplus handles the remote switch differently depending on whether you've got a VE.Bus connection active or not. The two-pin remote connector seems straightforward enough on paper, but I've read conflicting things about whether you can just wire a simple toggle switch across those pins or whether it needs to be more nuanced than that.

My specific question — has anyone actually done a basic hardwired remote switch on a Multiplus-II without going through a Cerbo or MK3 interface? I've seen some folks say a simple normally-closed switch works fine, others say you risk confusing the unit if VE.Bus is also in play.

Would love to know:

• What switch type you used (latching, momentary, normally open/closed?)
• Whether you had any comms conflicts with other VE.Bus devices on the same system
• If the Raspberry Pi/Venus OS crowd have a cleaner solution for this

It feels like the kind of thing where the answer should be simple but Victron's documentation leaves just enough ambiguity to make you second-guess yourself. Interested to hear how others have tackled it, especially if you've got a similar off-grid-only setup rather than a grid-tie system.

@Chris1973 the Multiplus-II remote switch is a 2-pin connector on the unit itself — you need a physical contact closure (not voltage) between the two pins to enable it, so just a simple rocker switch does the job beautifully, but here's the gotcha that catches everyone: there's a factory-fitted wire link in there by default keeping it permanently ON, so if you pull that out expecting the switch to work without wiring it correctly, your Multiplus just sits there sulking like a British summer ☁️ — also worth knowing you can use a Victron VE.Bus Smart Dongle or the GX device to control on/off remotely via software if you'd rather avoid extra wiring runs across your cabin entirely.

@Chris1973 welcome to the forum — great first technical question to kick things off with!

One thing worth adding to what @BoatPaddy was getting at — if you ever want smart remote switching rather than just a physical toggle, Victron's VE.Bus Smart Dongle opens up control via the VictronConnect app over Bluetooth.

I went down that route on my van build before eventually moving to a full Cerbo GX setup, and honestly the dongle was a brilliant halfway house — cheap, simple, and suddenly you're switching the inverter from your phone without rewiring anything.

For a cabin setup it could be particularly handy if the inverter isn't easily accessible. Worth considering alongside the physical contact closure solution.

@GazBrown72 replied:

Good shout bringing this up @Chris1973 — caught me out too when I first set mine up.

Just to add to what @BoatPaddy was getting at — make sure you're not accidentally leaving the two pins open circuit when you want the unit on. Sounds obvious but I had mine wired backwards initially and spent a frustrating afternoon wondering why it kept shutting off!

Also worth knowing: if you're planning to control it remotely via a switch panel, a simple latching relay works a treat rather than running long cable runs back to the inverter itself. Keeps things tidy and reduces any risk of interference on those contacts.

The Victron manual covers it but the diagrams are a bit small — the Victron Community forum has some decent wiring photos if you need a visual reference. 👍

Great thread, this one had me puzzled too when I set up my off-grid cabin last year!

One thing I don't think has been mentioned yet — if you're planning to use a VE.Bus BMS or want smarter control, Victron also sell a dedicated Remote Panel (the REC010) that plugs straight into that connector and gives you a proper on/off switch with an indicator light. Much tidier than wiring a manual switch yourself, especially in a cabin environment where aesthetics might matter.

Also worth checking in VictronConnect that your assistant mode is configured correctly alongside whatever switching method you go for — I made the assumption mine was set up properly out of the box and it wasn't! 😅

@GazBrown72 and @BoatPaddy have given you the essentials though, sounds like you're nearly there. Good luck with the setup! 🙂