ESS Assistant Not Detected Despite ESS Present in VEConfigure

Been wrestling with something similar on the narrowboat for the past week and it's doing my head in.

Running a MultiPlus-II 48/3000 paired with a Cerbo GX and a SmartSolar MPPT 100/50, all talking nicely to each other via VE.Bus and VE.Direct. ESS Assistant is sitting there in VEConfig exactly where it should be — loaded, saved, sent to the inverter without errors.

Yet the Cerbo flatly refuses to acknowledge it exists. No ESS menu. No scheduled charging. Nothing. Just stares back at me blankly like I've asked it something offensive.

I've tried the obvious:

• Re-flashing firmware on the MultiPlus (v500 and v502 both tried)
• Factory resetting the Cerbo and rebuilding from scratch
• Different VE.Bus cable (yes, really)
• Manually triggering a re-detection via Remote Console

What's baffling me is that the VRM portal does show ESS-related data fields, so something is getting through — just not fully registering on the GX side.

Wondering if this is a known firmware mismatch between the Cerbo and the MultiPlus-II at certain versions. The Victron community forums have a few threads but nothing that maps cleanly onto my exact setup.

Anyone on here run into this on a boat or off-grid setup where grid-code settings might be complicating things? I'm wondering if the UK grid profile is interfering somehow during the assistant detection handshake.

Would genuinely appreciate a fresh set of eyes on this — sometimes you need someone who's actually crawled around a bilge fighting with comms cables to understand the full picture. 🛶

@DorsetCamper this one caught me out too on the boat. The ESS assistant won't show as active on the Cerbo until the VE.Bus firmware on the MultiPlus-II is at a compatible version with your VEConfigure — classic mismatch issue.

Check your MultiPlus-II firmware via the Cerbo's device list. If it's below 490 or so, the Cerbo GX simply won't handshake properly with ESS even though VEConfigure shows it loaded.

Steps that sorted mine:

1. Update MultiPlus-II firmware via VE.Flash or through the GX directly
2. Re-upload the ESS assistant in VEConfigure after the firmware update
3. Full power cycle — not just a reset

Also worth checking your VE.Bus cable seating. A slightly dodgy MK3-USB connection mid-configuration can corrupt the assistant upload silently, which looks identical to this symptom.

@DorsetCamper had almost the exact same headache on my narrowboat last winter. What finally cracked it for me was realising the firmware versions weren't aligned across the system — MultiPlus, Cerbo, and the MPPT all need to be playing nicely together before ESS behaves itself.

Specifically, check your MultiPlus firmware through VictronConnect before touching VEConfigure again. Mine was sitting on an older build that simply didn't handshake properly with the Cerbo's ESS logic, even though the assistant appeared configured correctly on paper.

Also worth confirming your VE.Bus cable is seated properly — sounds obvious, but a slightly dodgy connection gave me ghost readings that looked identical to an ESS detection failure.

Pull the system log from the Cerbo's remote console and look for any VE.Bus error codes. That'll tell you far more than staring at the assistant configuration screen.

Had this exact issue setting up the ESS on my motorhome build last year. One thing nobody's mentioned yet — double-check your VEConfigure version matches what the Cerbo expects. I was running a slightly outdated version and the assistant config wasn't being read properly even though it looked correct in the software.

Also worth checking: is your DVCC actually enabled on the Cerbo? Easy to overlook but ESS basically won't play ball without it. Settings → System Setup → DVCC.

If you've got a Fogstar or similar BMS in the loop, make sure it's properly communicating too — a BMS that's not handshaking correctly can make ESS behave very oddly on the GX dashboard.

Hey @DorsetCamper, worth checking something that tripped me up on a similar setup — make sure your VE.Bus firmware on the MultiPlus-II is actually compatible with the ESS assistant version you've loaded. I had a situation where the assistant appeared correctly in VEConfigure but the Cerbo still wouldn't acknowledge it because there was a firmware mismatch between the two.

Also, are you connecting via the VE.Bus cable directly or through the MK3-USB interface? On my barge install I found the Cerbo needed a full power cycle (not just a reboot) after pushing the assistant config — completely disconnect shore power and batteries for a minute or so. Sometimes it just needs that hard reset to properly handshake with the MultiPlus-II and recognise the ESS assistant as active.

Building on what @BurnBen mentioned too, check the Cerbo's Remote Console under ESS — sometimes the mode shows as unconfigured even when everything else looks fine.

Firmware and double-checks aside — one thing that's caught people out and hasn't been mentioned yet: ESS requires the Cerbo to be set as the hub, not the MultiPlus. If your VEConfigure grid code isn't matching what the Cerbo expects, the assistant simply won't register properly even if it appears installed.

Also worth checking — are you connecting via VE.Bus directly or through the GX device? I've seen setups where someone's made changes through both routes and they've ended up conflicting. Pick one and stick to it.

On my shepherd's hut setup (granted, no ESS needed there) I learned the hard way that VEConfigure changes don't stick properly unless the MultiPlus is disconnected from the Cerbo during configuration. Reconnect after you've written the settings. Sounds obvious but it trips people up constantly.