Help with Victron Quattro integration with 3 x Pylontech Fidus Plus 16KWh

Been lurking on this thread with interest because I'm in a similar situation with my static caravan setup, though on a smaller scale.

Currently running a Victron MultiPlus-II with a single Pylontech US3000C and I'm already second-guessing whether I configured the DVCC settings correctly. So seeing someone tackle three Fidus Plus units at 16KWh each is making my head spin a bit — that's a serious chunk of storage.

A few questions I'd genuinely like to understand better, partly for my own benefit:

• Are you using a Cerbo GX to handle the BMS comms between the Quattro and the Pylontech stack, or going another route?
• With multiple Pylontech units, are they all daisy-chained via the CAN bus with the master/slave setup? I've read conflicting things about whether the Fidus Plus plays nicely that way
• What charge current limits are you seeing pushed through from the BMS to the Quattro? I'm curious whether Victron honours them properly at that scale

The Victron documentation is decent but there always seems to be a gap between what the manual says and what actually works in practice — especially around the ESS assistant settings if you're also grid-tied or generator-linked.

Has anyone else here run a large Pylontech stack with a Quattro specifically? I'd have thought this is becoming more common in static caravan and off-grid cabin installs across the UK, but finding people who've actually done it rather than just theorised about it is harder than it should be.

Would be good to get some experienced eyes on this one.

@GrumpyDrifter interesting timing — I'm also running a static caravan setup and been looking hard at Pylontech options.

Curious what MultiPlus-II size you've gone for? I'm on the 3000VA and wondering whether it's worth upgrading before adding a second battery rather than after.

One thing I've been trying to get my head around — with the Pylontech US3000C vs the newer Fidus Plus, is the CAN bus integration noticeably different on the Victron side? I've seen mixed comments on the Victron community forum about whether the Fidus shows up cleanly in VRM or needs any fiddling with the DVCC settings.

Also worth mentioning my use case includes occasional EV charging which I suspect changes the calculus on whether one large bank or staged expansion makes more sense for peak draw management.

@GrumpyDrifter your post got cut off — what Pylontech unit are you running currently?

Worth noting for anyone considering Pylontech: the US2000/US3000 series communicate over CAN bus with Victron kit natively, dead straightforward. The newer Phantom-S and Force H2 are a bit different story depending on firmware.

For a static caravan I'd argue you rarely need the full Quattro unless you're doing serious EV charging or running two AC sources. MultiPlus-II is almost certainly sufficient and considerably cheaper.

Make sure your Victron firmware is current — DVCC settings matter a lot when Pylontech is handling its own BMS comms. Gets pedantic but people mess this up constantly by setting charge voltages manually and fighting the BMS.

@GrumpyDrifter your post got cut off mate, we're all hanging here like a bad cliffhanger on EastEnders 😂

For what it's worth I've got a similar static caravan situation — Victron MultiPlus-II paired with Fogstar Drift batteries rather than Pylontech, but the integration headaches are basically identical regardless of what cells you've thrown money at.

Main thing I'd flag: make sure your DVCC settings are properly configured before you do anything else, because getting that wrong with Pylontech specifically is a classic way to confuse your BMS into doing absolutely nothing useful.

Also — what firmware version are you running on the MultiPlus-II? Had a genuinely awful weekend discovering that the older firmware doesn't play nicely with certain Pylontech communication protocols. Venus OS version matters too if you've got a Cerbo in the mix.

@GrumpyDrifter mate your post cutting off mid-sentence is giving me Pylontech anxiety and I don't need that on a Monday.

@GrumpyDrifter the suspense is genuinely worse than finding out your Fogstar cells arrived during a Royal Mail strike.