Issue with VRM graphs, Inverter mulit RS 48/6000 (without solar) + Cerbo GX

Been battling something similar across two of my installations and wondered if anyone else has hit this wall.

Running a Victron Multi RS 48/6000 purely as an inverter/charger (no solar input active), paired with a Cerbo GX on Venus OS v3.75. The hardware itself is performing fine, but the VRM portal graphs are throwing up some odd behaviour — specifically around the AC loads and battery state-of-charge traces. The SoC line occasionally drops off completely for periods, then snaps back, which makes historical analysis pretty much useless for those windows.

A few things I've already ruled out:

• Data logging interval — set to 1 minute, same as my other sites
• DVCC — enabled and configured correctly
• Cerbo connectivity — solid 4G via a Huawei router, no dropout events logged

What I suspect is that the Multi RS is reporting differently over VE.Can compared to a standard Quattro or Multi, and the Cerbo's data handling for this particular device may have some edge cases in the firmware. The RS series is still relatively young in Victron's lineup and I wouldn't be surprised if there are some VRM integration quirks still being ironed out.

Has anyone specifically run the Multi RS without any MPPT connected and noticed VRM graph anomalies? I'm wondering whether the inverter-only operating mode triggers a different data reporting path.

Also curious whether upgrading to v3.10 large on the Cerbo makes any difference — some reports suggest the newer builds handle RS series comms more cleanly.

Would appreciate hearing from anyone running a similar stripped-back setup.

@SolarCol yeah the VRM graphs go a bit haywire when the Multi RS has no MPPT source active — it's essentially expecting solar data to contextualise the power flow visualisation and when that's absent things get... weird.

On my static caravan setup I ran the Multi RS for about three months purely on grid-charge before adding panels, and the VRM dashboard showed phantom "solar" readings occasionally, plus the inverter/charger split on the graphs was unreliable.

Few things worth checking:

• DVCC settings — make sure SVS/SCS are configured correctly through the Cerbo
• Check your ESS assistant configuration if you're running one; the Multi RS behaves oddly in VRM without a proper ESS or "keep batteries charged" mode declared
• Firmware on both devices current? There were some Cerbo GX releases that specifically addressed Multi RS communication edge cases

What firmware versions are you actually running on the Cerbo and the Multi RS itself?

Ah, pedant hat on for a sec —

The Multi RS is fundamentally a solar inverter that's been press-ganged into inverter/charger duty. VRM sees "RS" and basically assumes solar data must be coming... somewhere. When it isn't, the graphs throw a bit of a strop like a sat-nav that can't

Good shout from @VanRhys there. One thing worth checking on VRM is whether you've got the device instance set correctly on the Cerbo — I've seen phantom readings and broken graphs simply because the Multi RS was registering as a solar charger device class rather than an inverter/charger when no PV source is present.

Worth jumping into the Cerbo's device list and confirming what role it's actually reporting. There's also a known quirk where the "Solar & Wind" graph panel just returns null values rather than zero when the MPPT inputs are unused, which VRM then renders oddly.

What firmware are you both running on the Cerbo? There were some VRM portal fixes in recent releases that tidied up exactly this sort of display issue with hybrid devices running in charge-only or invert-only modes.

@CotswoldNomad makes a fair point about the Multi RS's solar-first architecture, and it's worth expanding on the practical implication: because the RS firmware expects PV data to populate certain VRM widgets, you'll get blank or zero-value entries that skew your energy flow diagrams even when the inverter/charger side is functioning correctly.

One thing I've not seen mentioned — check your VRM Advanced tab and manually build a custom dashboard using the raw MQTT datapoints rather than relying on the auto-generated overview. The dc_power and ac_output attributes come through cleanly even without MPPT active; it's purely the visualisation layer that falls over.

On my own setup I had identical ghost readings until I excluded the PV widget entirely from the overview page. Victron's GX firmware v3.10+ may also have addressed some of this — worth checking your Cerbo is current via Remote Console → Settings → Firmware.