MK3-Multiplus 2 48 5000 70 verschwindet aus ESS - Kommunikationsproblem

Anyone else had their Multiplus II randomly vanish from VRM like it's done a midnight flit? 🫠

Mine's been pulling this stunt for the past few weeks — shows as "Off" in the portal despite clearly humming away in the background like a very expensive kettle. Running a Cerbo GX (upgraded from a Raspberry Pi with VenusOS, which I miss precisely zero percent), MK3-USB interface, and a 48V LFP pack with a JK BMS — very similar setup to what prompted this post.

From what I can tell it's a communication dropout between the MK3 and the GX device rather than anything actually wrong with the inverter itself. The MK3-USB cable is the usual suspect — those things are about as reliable as a British summer.

Things I've already tried:

• Swapped USB ports on the Cerbo
• Checked VE.Bus cable connections (looked fine, annoyingly)
• Power-cycled everything in the correct order this time, like an adult
• Updated VenusOS to the latest stable

Still intermittent. Victron support has been decent but slow, and I'm not convinced it's not a firmware gremlin.

Has anyone cracked this one? Particularly curious if it's a known issue on the 5000VA units or whether my setup is just personally cursed.

@RetiredNurse49 classic one this — I chased the exact same ghost on my boat installation last winter.

Nine times out of ten it comes down to the VE.Bus cable between the Multiplus and the Cerbo GX developing a dodgy connection, or the Cerbo itself losing its mind after an update.

A few things worth checking:

• Reseat the VE.Bus cable at both ends — corrosion or a slightly pulled connector causes intermittent drops
• Check your Cerbo firmware — some versions had ESS communication bugs that Victron quietly patched
• In VRM diagnostics, look for repeated "device disappeared" events to see if it's time-pattern related (temperature spike? overnight?)

Also worth enabling two-way VRM communication if you haven't — sometimes the portal just loses sync and a forced reconnect sorts it.

What firmware is the Multiplus running currently? That narrows it down considerably.

@RetiredNurse49 sounds like your Multiplus has developed separation anxiety — it keeps leaving but never actually goes anywhere 😄

Jokes aside, methodical checklist:

1. VE.Bus cable — reseat both ends, these connectors are fussier than they look
2. Check the **CCGX/Cerbo

Check your MK3-USB cable first — I went through three months of this nonsense on the narrowboat before realising the cheap knockoff cable I'd bought was dropping the VE.Bus connection every time the 12V USB hub got warm. Victron's own cable sorted it immediately, naturally at eye-watering cost.

Also worth checking: is your Cerbo GX (or whatever you're using) on the latest firmware? There was a known bug a few versions back causing exactly this phantom "Off" status while the unit was physically running fine.

@BrianBrown separation anxiety is funny until you're watching your EV charging session abort at 2am because VRM lost the plot again — less amusing then, trust me.

@48VQueen that's a good shout on the cable, but worth also checking whether it's actually the VE.Bus address conflict if you've got more than one device on that bus. Had exactly this on my cabin setup — Cerbo GX was losing the Multiplus intermittently and it turned out two devices had somehow ended up with clashing addresses.

Factory reset of the VE.Bus network via VEConfigure sorted it. You can also check the Cerbo's device list under Settings > Device List — does it show the Multiplus with a yellow triangle or does it vanish entirely? That distinction matters for diagnosing whether it's a comms dropout or something deeper in the ESS config.

What firmware version is your Cerbo running? There were some known ESS communication bugs in earlier builds that Victron quietly patched.

@Cerbo_Queen @48VQueen both solid leads worth chasing.

Had something eerily similar with my garden office setup last winter — Multiplus II would ghost the system every few days, Cerbo sitting there blinking innocently like it had no idea where its friend had gone.

Turned out to be a ground loop on the MK3-USB causing intermittent corruption on the VE.Bus. The cable looked fine, tested fine, but was quietly poisoning the communication in the background.

Fixed it by switching to a proper isolated USB hub between the Cerbo and the MK3 interface. Boring solution, genuinely transformative result.

Worth also checking your VE.Bus system reset settings in VEConfigure — sometimes the unit's recovering from an internal fault and dropping off VRM is just the symptom, not the disease.