Anyone else running Victron Cerbo GX with a mix of MPPT controllers — how are you handling the VRM data gaps?

Been running a Cerbo GX as the hub of my system for about eight months now and mostly love it, but I keep hitting the same frustrating issue. When my internet goes down (which out here in rural Wales is more often than I'd like), the Cerbo logs locally and then tries to sync to VRM once connectivity comes back. Problem is I'm regularly seeing 2–4 hour gaps in the historical data after these outages, even though the SD card logging should be catching everything locally. Running firmware 3.30 on the Cerbo if that's relevant.

My setup is two Victron SmartSolar 100/30s and one 150/45, all on VE.Direct, feeding a 400Ah lithium bank. Everything talks to the Cerbo fine in real time via the local dashboard, so it's not a comms issue between devices. The gaps only show up in VRM once it resyncs. I've tried bumping the local log interval down to 1 minute thinking that might help but it doesn't seem to make any difference to the missing chunks.

Has anyone actually got the local SD sync to VRM working reliably after an outage, or is this just a known limitation people live with? Also curious whether anyone's pairing something like Home Assistant alongside VRM to plug these gaps — I've seen a few mentions of the Victron MQTT integration but haven't gone down that rabbit hole yet.

@IanWhite oh mate, I lived this saga on the narrowboat last winter. Signal dropping out mid-canal somewhere between Braunston and absolutely nowhere.

The trick that saved my sanity: Cerbo GX local data logging still runs regardless — it buffers up to 30 days internally. When connectivity returns, VRM backfills automatically. You're not actually losing data, just not seeing it in real-time.

For the mixed MPPT situation specifically:

• Make sure each controller has a unique VE.Direct device instance assigned
• Check your VRM dashboard aggregation settings — it sometimes lumps controllers together stupidly

The bigger gotcha with multiple MPPTs is the Cerbo occasionally losing a VE.Direct device after a firmware update. Fixed mine by forcing a device rescan through Remote Console.

Are you running any non-Victron controllers in the mix? That changes things considerably — the data gaps get genuinely annoying rather than just cosmetically irritating.

@IanWhite curious whether you've actually confirmed the Cerbo's local SD card is logging continuously during those dropouts, or are you assuming it is? Because I made that assumption with mine and discovered the card had silently filled up weeks earlier — no warning whatsoever from VRM.

Also, when the connection restores and backfills into VRM, are your MPPT controllers (which models specifically?) all reconciling their data at the same timestamp resolution? I've got a SmartSolar 100/30 alongside an older BlueSolar and I noticed the historical sync intervals differ, which creates these odd-looking phantom gaps in the dashboard graphs that aren't actually missing data — just mismatched aggregation windows.

What's your internet connection method out there — 4G router, satellite? That might change what solutions are actually practical for you.

Yeah @IanWhite the rural connectivity struggle is real — I'm in mid-Wales and gaps in VRM are just part of life here.

One thing worth checking: in the Cerbo's settings under Remote Console > VRM Portal, you can tweak the logging interval down to 1 minute locally even when offline. The data backfills to VRM once you're reconnected, so you don't actually lose it, it just appears later. Took me an embarrassingly long time to realise that.

@FormerMariner1 raises a fair point though — worth SSHing in and manually confirming the local log files are actually growing during an outage rather than just assuming they are. Mine had a dodgy SD card that was silently failing.

What MPPT controllers are you mixing? If you've got non-Victron units on there via a generic meter, the logging behaviour can differ slightly.

Hey @IanWhite, worth knowing the Cerbo will buffer up to roughly 24 hours of data locally and then sync it back to VRM once connectivity resumes — so shorter outages usually backfill themselves automatically without you losing anything. The gaps you're seeing in VRM might actually just be display artefacts rather than genuine missing data. That said, if your outages are longer than that buffer window, I'd look at a 4G router with a decent external antenna rather than relying on a dongle — made a huge difference for me. Also, @FormerMariner1 raises a good point about the SD card — worth SSHing in and checking the logs folder directly to verify what's actually being captured locally. What's your current connectivity setup out there?

@Andy1979 that 24-hour buffer is good to know — but what happens when the outage stretches longer? I'm on a boat and sometimes I'm off-grid for days at a stretch with no signal. Does the Cerbo just start dropping the oldest data once the buffer fills, or is there a way to extend local storage capacity?

Also curious whether anyone's tried pairing the Cerbo with a local Grafana/InfluxDB setup as a proper offline fallback — I've seen it mentioned but never found a clear "here's how you actually do it" guide. Seems like overkill for a shepherd's hut setup but for a live-aboard situation where I genuinely need the historical data it might be worth the faff.

Anyone gone down that rabbit hole? 🐇