CerboGX weird display on brief page

So this one's been niggling at me for a few weeks and I finally decided to post about it.

Running a fairly beefy setup in my static off-grid place — two Multiplus-II 5000s in parallel, a Victron Cerbo GX, and a mix of Fogstar Drift cells I built into a 48V pack myself with a Daly smart BMS. Panels are split across a couple of Victron MPPT 150/70s and I've got AC coupling through a Solis inverter on the output side.

The Brief page on the Cerbo has started showing some genuinely baffling numbers. Specifically, the battery power figure seems to jump between charging and discharging states within the same second — even when everything is stable and sunny. We're talking flicking from +800W to -200W with no apparent reason. The Solis is chuntering away happily, batteries are sitting at a comfortable 54V, nothing alarming on the BMS side.

My gut says it's a measurement lag or rounding issue between the AC coupling data and what the Cerbo is actually calculating in real time. The maths doesn't always add up cleanly when you've got power coming in from multiple sources simultaneously — at least that's my working theory.

Has anyone else with AC-coupled setups noticed this? I'm sceptical it's actually a real fluctuation rather than a display artefact, but I'd love to know if anyone's dug into the ESS assistant settings or DVCC configuration and found something that tidied it up.

Curious whether this is a firmware thing too — worth raising on the Victron Community, or has someone already solved it here?

Reply by EwanScott:

@LiFePO4Nerd Looks like your post got cut off there, mate — we're missing the actual setup details and what the display is doing! Give us the full picture when you get a chance.

That said, I've seen some odd behaviour on the Brief page with parallel Multiplus-II setups before. One thing worth checking straight away is whether your VE.Can or VE.Bus firmware is consistent across both units — mismatched firmware between paralleled inverters can throw up some genuinely confusing readings on the Cerbo that look like display bugs but aren't really.

Also, what firmware version is your Cerbo running? There were a few quirks in some earlier 3.x builds that caused Brief page oddities specifically with battery data. Worth updating if you haven't recently.

Post the rest of your setup details and I'll try to help properly!

@LiFePO4Nerd @EwanScott

Aye, post got mangled. Seen it happen on this forum before when people paste in long blocks.

That said — "weird display on brief page" rings a bell from my van build. Had a Cerbo throwing odd readings on the brief overview after I'd done a firmware update. Turned out the SOC calculation was having a argument with the BMS data because the battery capacity figure in VRM didn't match what the Daly BMS was reporting.

Worth checking your Device List → Battery Monitor settings and making sure your configured capacity matches reality. Also — which BMS are you running? Some of the cheaper units send malformed data over VE.Can that the Cerbo just about tolerates but displays oddly.

Post the full setup details when you get a chance and somebody here will likely recognise it.

@LiFePO4Nerd while we wait for the full post — the thread title's giving me flashbacks. Had something similar on my narrowboat Cerbo last winter, brief page showing nonsense values that didn't match what the BMV or the Multiplus were actually doing.

Nine times out of ten with parallel Multiplus setups it's a VE.Bus configuration mismatch — the brief page pulls data differently than the main dashboard and inconsistencies show up there first.

Worth checking:

• Both units running identical firmware
• VEConfigure showing them properly paired, not just "connected"
• Whether the weirdness tracks with load spikes or just appears randomly

Post your actual setup details when you get a chance and I'll have a proper look. Parallel Multiplus troubleshooting is fiddly enough without guessing at the config.

Reply by AnneHenderson82:

@LiFePO4Nerd Chiming in while we wait for the full post to appear — the "brief page" on the Cerbo does throw up some odd readings occasionally, especially if the BMS comms aren't playing nicely with VRM. Worth checking your DVCC settings while you're sorting the post out.

@WezFisher ooh, don't leave us hanging either! Your reply also got chopped 😄

@LiFePO4Nerd if you're struggling to repost the full thing, try typing it directly rather than pasting — seems to behave better on this forum. Would love to see your full setup details, two Multiplus-II 5000s in parallel sounds like a serious install. Curious what battery bank you're running with that.