Feature Request: Dynamic Phase-Aware Power Limiting for EV Charging Station in 3-Phase Systems

This one's been nagging at me for a while, so glad someone else is raising it.

My setup runs a Victron Quattro-based 3-phase system — originally built for emergency backup during outages, but it's grown into something more elaborate over the years. When I added EV charging into the mix, I hit a wall almost immediately. The EVCS doesn't seem to understand that phases aren't equal citizens in a real-world domestic installation.

What actually happens is that the system applies a blanket current limit across all three phases based on the weakest constraint. So if one phase is already under load from the house circuits, the whole charging session gets throttled — even when the other two phases have headroom to spare. You end up leaving kilowatts on the table for no good reason.

What I'd love to see — and what seems technically achievable given how capable the Venus OS platform already is — is per-phase dynamic limiting. Let the EVCS read individual phase loads from the grid meter or MPPT data, then adjust current allocation intelligently rather than just applying the same cap across the board.

Has anyone on here actually managed a workaround through Node-RED or custom Venus OS scripts? I've been eyeing a flow-based approach but haven't committed the time yet.

I imagine this matters more to those of us running hybrid systems with variable domestic loads — workshops, immersion heaters, that sort of thing — rather than a clean dedicated circuit. The unbalance is basically baked in.

Worth pushing Victron on this through their feature request channels, or does anyone know if it's already on their roadmap?

Not my area of expertise (single phase van life here 😄) but I wanted to say this sounds like a genuinely useful feature request @SolarRachel.

From what I understand, the Victron ESS assistant already does some load limiting magic, but 3-phase dynamic balancing for EV charging is a proper gap.

Worth posting this directly on the Victron Community forum if you haven't — the devs actually monitor it and feature requests do get picked up there. A few users have had success getting things into the Venus OS roadmap that way.

Also tagging @victron_uk on Twitter sometimes gets traction. Might be worth a shot alongside raising it here! 🤞

Great thread @SolarRachel! This is something I've been wrestling with on my own Quattro 3-phase setup too.

The real headache is when one phase gets hammered by the EV whilst the others sit relatively idle — your batteries end up compensating unevenly and the BMS starts throwing fits trying to balance everything out.

Have you looked at the DVCC (Distributed Voltage and Current Control) settings in VenusOS? There's some limited per-phase current limiting available, but it's nowhere near sophisticated enough for dynamic EV load management.

Victron's community forum has a few feature requests along similar lines — might be worth cross-posting there to get some traction directly with their developers. Node-RED running on a Cerbo GX could potentially be a workaround in the meantime if you're comfortable scripting a custom solution.

What firmware version are you running currently?

@SolarRachel this is basically asking your inverter to think in three dimensions simultaneously, which is roughly what I ask of my narrowboat's single Victron MultiPlus every time I run the kettle and the microwave. It panics. Can't blame it.

The phase-balancing bit is where it gets genuinely tricky though — most B

@SolarRachel this is a well-defined problem and worth pushing Victron on via their GitHub feature requests — they do actually engage with those.

The crux technically is that the Quattro's current assistant framework handles AC-in current limiting per-phase already, but it doesn't expose that logic to external modulation dynamically without going through Venus OS and custom MQTT scripting. I've done something adjacent on my backup system — using Node-RED on a Cerbo GX to poll grid meter readings per-phase and throttle the ESS charge target accordingly. Not identical to EVSE phase-aware limiting, but the underlying mechanism is transferable.

The missing piece is a standardised interface between Venus OS and OCPP-capable chargers. Once that handshake exists natively, phase-balancing becomes tractable. @PanelSteve is right that it's multi-dimensional — but Victron already has most of the sensor data; it's purely a software arbitration problem at that point.