Configuracion DVCC con EVcharging station

Been thinking about this one a lot lately since a mate of mine is planning something similar.

He's got a Multiplus II 5kVA running his off-grid setup and wants to chuck a Victron EV Charging Station on the AC-OUT to charge his Nissan Leaf overnight. All powered by solar with a decent Victron/Fogstar lithium bank.

The question is around DVCC configuration — specifically whether the system plays nicely when the EV charger is pulling hard and the battery isn't fully topped up. From what I understand, DVCC with SVS and SCS enabled should let the Multiplus manage current limits sensibly, but I've seen conflicting reports about whether the EV charger actually respects those limits properly or just hammers away regardless.

A few things I'm curious about:

• Does anyone have the EV charger on AC-OUT rather than AC-IN? Seems like AC-OUT makes more sense for off-grid but I've heard it can cause issues
• What minimum SOC are people setting before allowing EV charging to kick in?
• Any Node-RED flows people are using to automate this based on solar forecast or battery SOC?

I've not got an EV myself (yet...) but I'm building out my backup system and this is on my radar for the future. Would love to hear from anyone who's actually got this running in the UK — especially on a grid-off setup rather than grid-tied.

What's the community's experience? Anyone had gremlins with DVCC and the EV charger conflicting?

Tell your mate to make sure DVCC is on and ESS is properly configured before he even plugs the EV station in, otherwise the MP2 will have an absolute meltdown trying to figure out what's in charge of what.

Really good point from @Smithy — and just to add from my own experience running something similar for my shepherd's hut setup...

The bit that caught me out was the charge current limit not flowing down properly from the BMS through DVCC to the EV charger. The Multiplus II was perfectly happy, BMS was screaming quietly in the background 😅

Your mate needs to check that SVS and SCS are enabled under DVCC too, not just the top-level toggle. Otherwise the system isn't actually sharing voltage/current sense data properly across the network.

Also — what BMS is he running? With a Fogstar or similar lithium setup the DVCC interaction is slightly different to a lead-acid situation. Worth knowing before he starts poking settings at 11pm like I did...

Good shout from both @Smithy and @VivaroNomad.

One thing worth flagging specifically for the EV Charging Station — make sure the AC grid code is set correctly in VEConfigure. It's easy to overlook when you're deep in the DVCC settings rabbit hole.

Also worth knowing: the EVCS talks to the Multiplus II via VE.Bus/Cerbo GX, so if your mate's not running a Cerbo or equivalent GRM device, he'll lose a lot of the smart charging functionality — it'll basically just run dumb.

I've got a similar arrangement on my boat (different scale, mind) and the Cerbo is genuinely the glue holding it all together. Without it, DVCC coordination between the charger and the inverter gets messy.

Worth double-checking the minimum SOC threshold too before enabling EV charging — you don't want the car draining the house bank.

Good points all round, but one thing I'd add from bitter experience — don't overlook the minimum current setting on the EV Charging Station.

When the Multiplus II starts throttling back due to battery SOC or solar input dropping, the EVCS needs a floor to work with. If your mate's EV (particularly older Type 2 kit) can't accept below 6A per phase, you'll get frustrating charge interruptions rather than graceful tapering.

In my motorhome setup I had something analogous with a smaller load and it drove me absolutely mad until I sorted the charge current floor in VRM/GX device settings.

Also worth confirming his GX device firmware is current — there were some rough edges in earlier builds around EVCS integration with DVCC that Victron quietly ironed out. Check the changelog before assuming it'll just work.

@LiFePO4Nerd good shout on the minimum current — burned an afternoon troubleshooting that exact thing on my motorhome setup before I twigged.

One thing nobody's mentioned yet: make sure your DVCC charge current limit is actually being respected by the EVCS. In my experience it can lag behind when the BMS starts pulling back — there's a response time issue. Victron's own docs acknowledge it's not instant.

Workaround I've seen recommended is setting a slightly conservative upper limit in DVCC rather than letting it run right to the edge. Bit of headroom saves grief.

Also — what firmware version is he on? There were some properly annoying EVCS/DVCC interaction bugs in earlier releases. VRM portal should tell him straight away.

What @LiFePO4Nerd and @OffGridMax said about minimum current rings true, but the bit I'd add from my shepherd's hut setup — DVCC with shared voltage sense becomes your best friend here, not just shared current sense.

Without it, the Multiplus and the EV charger can end up in a bit of a tug-of-war deciding what the battery actually wants. Took me an embarrassingly long time to realise my Fogstar cells were cycling oddly because of exactly that.

Also worth checking the ESS assistant version his Multiplus is running — older firmware had some quirks with dynamic current limiting that Victron quietly sorted in later releases. Venus OS side needs to match.

Good thread. One thing not yet mentioned — with DVCC active, make sure the SVS (Shared Voltage Sense) and SCS (Shared Current Sense) flags are configured correctly across your VE.Can network before you even touch the EV charger settings. Got caught out on my narrowboat when the Multiplus II was reading voltage from the wrong source entirely, which threw the whole charge curve off. Check in VRM that the EVCS is actually appearing as a proper load and being factored into the ESS assistant's calculations rather than being invisible to it.