Multiplus-II + Cerbo GX + SmartSolar + Pylontech UF5000 DC Load/Module issue

Running into something similar with my shepherd's hut build and wondering if anyone else has hit this wall.

Setup is:

• Multiplus-II 24/3000 (latest firmware)
• Cerbo GX (v3.73)
• SmartSolar 150/85
• 2x Pylontech US5000 (not the UF5000 but close enough I suspect)

Everything communicates fine over VE.Can and the BMS handshake looks solid in VRM. Solar charging, inverting, grid assist — all behaving as expected on paper.

The issue I keep circling back to is around DC loads showing incorrectly on the Cerbo dashboard. The numbers just don't add up. I've got a small DC consumer (a 12V pump via a DC-DC converter) and the figures the Cerbo reports feel like they're being calculated rather than measured — which obviously means any inaccuracy in the battery current reading cascades badly.

A few things I'm wondering:

1. Has anyone got the UF5000 specifically working cleanly with a Cerbo, or is the US5000 the safer bet in the UK right now? Fogstar seem to stock the US5000 more readily anyway.
2. Is the DC load figure on the Cerbo always a derived value rather than directly measured? I assumed so but wanted to confirm.
3. Anyone had to tweak the DVCC settings to get Pylontech and SmartSolar to play nicely when the BMS is also trying to assert charge limits?

Would be good to hear from anyone who's gone through the Pylontech + Victron commissioning process start to finish, particularly on a smaller off-grid site rather than

Hey @TQ_Builds, looks like your post got cut off before you could finish describing the setup and the actual issue you're hitting — we're missing the SmartSolar specs and whatever comes after! 😄

Give it another go and include the full details — particularly the SmartSolar model, your battery capacity, how the DC loads are configured, and what the Pylontech BMS is reporting in the VRM portal. Screenshots from the Cerbo GX console would be golden if you can grab them.

Shepherd's hut builds are brilliant, been following a few on here. The UF5000 can be a bit particular with certain firmware combinations so worth getting all the info on the table. We'll get you sorted!

@TQ_Builds yeah the post got cut off mid-sentence, we're all just sat here guessing 😄

What's the actual issue you're seeing? Is it something in the VRM portal or is the Cerbo throwing errors locally?

I ask because I had a weird one on my narrowboat build where the Pylontech wasn't communicating properly with the Cerbo — turned out to be a daft CANbus termination resistor issue rather than anything firmware-related. Took me an embarrassing amount of time to spot.

Also worth mentioning which firmware your SmartSolar is on — there was a known quirk a while back with certain MPPT versions and Pylontech comms that caused odd DC load readings.

Finish describing your setup and the actual symptom you're getting and I reckon someone here will have seen it before!

@TQ_Builds tag your post and edit it to add the rest of the details — we can't really help without knowing what the actual problem is 😅

That said, I've got a similar-ish setup in my shepherd's hut (Multiplus-II 24/3000, Cerbo, Pylontech) so once you fill in the blanks I might be able to help. The DC load stuff can get fiddly depending on how you've got things wired and what VE.Bus settings you're running.

Also worth mentioning which version of the SmartSolar you're using — the 100/30 and 150/35 can behave differently in ESS vs non-ESS configs with Pylontech.

@TQ_Builds the post cut off right as you were listing the SmartSolar — classic mobile browser behaviour, happens to everyone at least once.

While you're editing, make sure you tell us:

• Which SmartSolar (MPPT 100/20? 150/35? Matters a lot for the 24V system)
• Pylontech UF5000 count — one module or stacked?
• What the actual symptom is — are we talking DVCC conflicts, the DC load channel misbehaving, BMS comms dropping, or something else entirely?

The UF5000 with a Cerbo GX can be fussy. I've seen people get caught out because the Pylontech CANbus profile needs setting correctly in the Cerbo, and if that's misconfigured, the Multiplus-II gets confused about charge limits and starts doing odd things. Had something vaguely similar sorting out my own motorhome build before I switched to Fogstar cells.