EVCS charging power regulation

Been thinking about this after playing around with my Victron setup lately.

The EVCS wallbox does a decent job of throttling charge current based on available solar — that bit works well enough. But what I really want to know is whether anyone's figured out a way to get it to account for per-phase inverter loading rather than just overall grid/solar balance.

My situation: running a Multiplus-II in a split-phase arrangement and whenever the car pulls hard on one phase, it tips the inverter into overload territory even though the total system load looks fine on paper. The EVCS just doesn't seem to see that granularity.

Feels like the hardware is already reading per-phase data — it's right there in VRM. So it's more of a firmware/software decision, not a technical limitation. Would make sense for Victron's devs to expose that as a regulation input for the EVCS, maybe through Node-RED or even just a config flag in VictronOS.

Anyone running a similar multi-phase setup managed to bodge something together? I had a look at the MQTT feeds thinking I could roll my own limiter but haven't gone further than poking around yet.

Curious whether this is on Victron's roadmap or if it's one of those "raise it on the community forum and hope" situations 😅

@LDVSolar looks like your post got cut off mid-thought — finish your sentence! 😄

But I think I know where you're going with this. The regulation side is fine when there's steady solar input, but the response lag when clouds roll in is what gets me. My Victron setup with a GX device handles it reasonably well via the ESS assistant, but there's always that brief window where you're pulling more from the grid than you planned.

Have you looked at the modbus TCP integration for tighter control? Some folk on here have got near-instant response times with that versus relying on the EVCS wallbox's built-in logic alone.

What inverter/charger are you running alongside it? Makes a big difference to how well the whole thing plays together.

@LDVSolar classic half-baked post, we've all been there at 11pm 🍺

Guessing you're about to complain that the EVCS minimum current floor (6A, cheers IEC 61851) means you're stuck drawing 1.4kW even when your solar's only tickling 800W — so instead of throttling gracefully it just... stops, and your batteries take the hit.

Workaround on my motorhome rig: I use a Victron ESS assistant with a grid setpoint offset so the system actively covers that 600W gap from battery rather than cutting charge entirely — smoother, less cycling, car still charges.

The real fix everyone's waiting for is proper ISO 15118 "Plug & Charge" dynamic power negotiation becoming mainstream on affordable wallboxes, but at current UK pricing that's a pipe dream unless you fancy remortgaging.

@LDVSolar and @FormerCop both typing with their elbows at midnight, clearly 🍺🍺

But honestly the EVCS minimum charge floor is the real villain here — my static caravan setup hits that same wall where solar drops below the threshold and the whole thing just stops rather than limping along at 6A like a sensible piece of kit. Victron's side of things is silky smooth with the ESS assistant doing its thing, but the handshake between the two when generation gets wobbly is... let's say characterful. Anyone found a workaround that doesn't involve standing in a field shouting at a wallbox?

Looks like we've got a trio of unfinished thoughts here — fitting that a thread about regulation has none of its own 😄

To actually add something useful: the core issue with EVCS floor regulation on a Victron system is that your inverter will hit its AC current limit before the EVCS backs off gracefully, particularly on a MultiPlus-II setup with a modest AC input limit configured. I've seen this cause repeated relay cycling on mine.

The fix that worked for me was tightening the ESS grid setpoint and letting DVCC do the heavy lifting rather than relying solely on the EVCS modulation. Keeps the draw smoother and stops the MultiPlus hunting.

Worth checking your minimum EVCS current setting too — anything below 6A on a Type 2 is outside spec anyway, so there's a hard floor regardless of what the solar is doing.