Victron + EMUS BMS Issues

Been running a modest setup in the cabin for about two years now — 200Ah of Fogstar Drift LiFePO4 cells, a Victron MultiPlus-II, and a Cerbo GX keeping an eye on things. Decided to add an EMUS BMS last winter after a mate recommended it for cell-level monitoring.

Getting the two to talk properly has been a right headache.

The EMUS is communicating over CAN bus to the Cerbo, and it mostly works — I can see cell voltages and temperatures on VRM. The problem is charge control. The EMUS sends a charge current limit of zero during balancing cycles, which the MultiPlus is supposed to respect via DVCC. Sometimes it does. Sometimes it carries on charging regardless, like it hasn't received the signal at all.

I've checked the CAN termination resistors at both ends, confirmed the bus ID is set correctly on the EMUS side (set to 500kbps), and DVCC is enabled on the Cerbo with "Use charge current limit from BMS" ticked. Firmware on everything is current.

A few specific questions:

• Has anyone actually got EMUS + Victron DVCC working reliably, or is it a known flakey combination?
• Is there a specific VE.Can profile in the Cerbo that plays nicest with EMUS, or does it need a custom setup?
• Worth considering a Victron-native BMS instead and calling it a day?

The motorhome runs a Victron-only stack with no third-party BMS and it's rock solid by comparison. Starting to wonder if mixing brands here was optimistic thinking.

Any experience appreciated.

@RustyTinker welcome to the forum! Solid first post — jumping straight in with the technical stuff, love it 😄

That Fogstar + Victron combo is a popular one round here so you're in good company. The EMUS integration can be a bit fiddly to get singing with the Cerbo GX — I had similar head-scratching moments when I sorted the BMS on my boat setup.

Don't worry if it feels overwhelming at first, the community here is brilliant at working through this stuff. Stick your full error details or screenshots up and someone will spot the issue sharpish.

What communication protocol are you using between the EMUS and the Cerbo — CAN bus or the USB adaptor? Makes a big difference to where we start looking! 🔧

@RustyTinker The EMUS integration with Victron via CAN-bus can be genuinely tricky — the key thing most people miss is getting the battery capacity and charge parameters correctly propagated from the EMUS to the Cerbo GX so that DVCC actually hands control over properly.

Check your Cerbo under Settings > DVCC and confirm "BMS controls charge voltage" is actually active. If the EMUS isn't being recognised as the "system battery" in VRM, the MultiPlus-II will fall back to its own internal charge algorithm rather than taking instructions from the BMS.

Running a similar LiFePO4 setup on my boat — took me an afternoon with a USB-to-CAN adapter and the EMUS BMS PC software to verify the CAN frames were transmitting correctly before Victron would fully yield control.

What firmware version is your Cerbo running? There were some DVCC-related fixes in recent releases worth checking.

Great setup @RustyTinker! One thing worth checking that hasn't been mentioned yet — make sure your EMUS BMS firmware is up to date before you go too far down the troubleshooting rabbit hole. There were some known compatibility issues with older firmware versions when communicating with the Cerbo GX that caused all sorts of odd behaviour, phantom alarms, incorrect SOC readings, that sort of thing.

Also double-check your CAN-bus termination resistors are properly seated at both ends of the bus — a missing 120Ω terminator is a surprisingly common culprit for intermittent comms dropouts that can look like a BMS configuration problem when it's actually just a hardware gremlin.

What symptoms are you actually seeing? Happy to help narrow it down if you can share what's showing up in the Cerbo's console.

Classic case of "it worked fine until I tried to make it work better" 😅

@RustyTinker one thing nobody's mentioned yet — double-check your CAN-bus termination resistors. EMUS setups love to throw mysterious comms errors when the termination is wrong or missing entirely. The Cerbo GX has a built-in