Connection issues with EVCS screen version

Has anyone else had grief with their EVCS (screen version) dropping connection after an initially smooth install?

I fitted mine back in March — all went well, showed up in VRM straight away, could schedule charging sessions no problem. Brilliant, I thought. Job done.

Then about three or four weeks in, the whole thing went a bit wobbly. It still appears in VRM, but the connection status is showing as questionable — can't interact with it properly, scheduling has stopped responding, and the screen on the unit itself is behaving oddly. It's not completely dead, just... disconnected in a way that's hard to pin down.

My setup:

• Victron Cerbo GX as the hub
• Multiplus-II 48/5000
• Fogstar lithium bank
• Everything else on the network is solid — no issues with the Cerbo talking to anything else

Things I've already tried:

• Power cycling the EVCS
• Checking the local network (router, IP conflicts, etc.)
• Re-pairing via the VRM portal

The odd thing is it was working — firmware updated fine on first install, no drama. Then it just quietly lost the plot. I've seen a few mentions online of similar behaviour but nothing with a definitive fix.

Is this a known firmware gremlin with the screen version specifically? Or could this be a VRM cloud side issue rather than the hardware itself?

Curious whether anyone's managed to fully resolve this or whether it needed a replacement unit. Any pointers much appreciated — it's slightly embarrassing having a fancy EV charger that I can't actually control! 😅

@Midge what firmware version is yours running? Mine did something similar a few weeks after install — turned out the Cerbo GX needed a manual update before the EVCS would maintain a stable handshake.

Also worth checking — is yours on WiFi or wired ethernet? I switched to a physical connection and the random dropouts stopped almost completely. WiFi interference seemed to be the culprit in my case, possibly from other kit nearby.

Did VRM show any error codes when it dropped, or does it just vanish from the device list entirely? Trying to narrow down whether it's a network issue or something deeper in the EVCS firmware itself.

@Midge this happened to me on my Transit build last autumn — rock solid on day one, then started dropping off VRM intermittently about six weeks in.

Turned out the culprit was the EVCS polling interval conflicting with my Cerbo GX when the inverter load spiked during charging cycles. Worth checking your DVCC settings if you haven't already.

Also — and this sounds daft — make sure the ethernet cable isn't sharing a conduit run with any AC wiring. I had some nasty interference causing phantom disconnections that looked like a firmware issue but wasn't.

@SprinterWanderer is likely onto something with the firmware angle though. What's your Cerbo on? If it's pre-3.40 there were known VRM comms gremlins that caught a lot of people out.

@Midge the classic "works brilliantly until you tell someone about it" syndrome — I've seen it on my narrowboat setup more times than I care to admit.

One thing worth checking that nobody's mentioned yet: the WiFi antenna orientation on the EVCS. Tucked behind a metal panel or bulkhead and it'll drop signal intermittently

@Midge mine did exactly this on the boat — turns out the EVCS screen version has a known strop with certain Cerbo GX firmware combinations, specifically if your Cerbo auto-updated itself in the background like a smug little gremlin while you weren't watching. Check your Cerbo is on the same recommended pairing firmware as the EVCS — Victron's compatibility matrix is buried in their docs like they're embarrassed by it. Also worth checking the RS-485 termination if you're running cable longer than a couple of metres; narrowboats are basically a floating interference generator and I'd assume vans aren't much better.

@48VQueen raises something worth digging into — firmware mismatches between the Cerbo and the EVCS have caught me out before on my sailing boat.

What I'd add is to check your VE.Can termination resistors. Sounds boring, but I once lost my mind for a fortnight convinced it was a software gremlin, only to discover one end of the bus wasn't properly terminated. Victron's own documentation buries this detail.

Also worth pulling the Venus OS logs rather than just watching VRM — the raw data often shows whether it's genuinely dropping or just failing to report. Two very different problems with different fixes.

@Midge — what firmware is your Cerbo actually running right now?