Small BMS NG on Cerbo GX with firmware V3.80

Been having a similar headache with my setup in the garden office and wondering if anyone else has hit this wall.

After updating my Cerbo GX to V3.80, the Small BMS NG connection via Bluetooth has become pretty unreliable. I'm getting what look like spurious alarms firing off constantly — cell voltage warnings, temperature flags, the lot — even when everything looks perfectly normal when I connect directly through Victron Connect on my phone. The BMS itself seems absolutely fine, readings are stable, no real faults.

So it does feel like the Bluetooth integration layer between the BMS and Cerbo is the culprit rather than the BMS doing anything wrong. Has anyone else noticed this specifically on V3.80, or did this start for some of you on an earlier firmware?

A few things I'm curious about:

• Is anyone running V3.80 with a Small BMS NG without issues, and if so, is there anything different about your setup?
• Has anyone found a workaround — whether that's rolling back firmware or using a VE.Direct cable instead of Bluetooth?
• Is there a known bug report lodged with Victron on this yet?

My system is relatively modest — Fogstar Drift 200Ah LiFePO4, Victron SmartSolar MPPT, Multiplus-II — so it's not a complicated configuration. The alarms being phantom ones is the frustrating part because it makes it hard to trust genuine alerts when they do appear.

Would appreciate knowing whether this is widespread or just me doing something daft.

V3.80 ate my Small BMS NG connection too — narrowboat life nearly became very expensive when the Victron ecosystem went deaf to the batteries mid-canal.

Rolled back to V3.74 via Victron's firmware archive and everything shook hands again like old mates.

Worth checking if your VE.Direct cable is an option as a fallback — Bluetooth on the Cerbo has always felt like it's held together with optimism anyway.

Same thing happened to me with my static caravan setup — woke up one morning to find the Cerbo had basically ghosted the Small BMS NG like a bad Tinder date 😄

Worth trying a full power cycle on both devices before anything else — obvious I know, but it sorted mine temporarily. Long term though, Victron's support thread suggests

Yeah had this exact problem on my static van after the 3.80 update dropped. Took me a day to even realise what had gone wrong — Cerbo just showed nothing, no error, no warning. Cheers Victron 🙄

Worth checking if your BMS firmware is actually current before assuming it's purely the Cerbo update causing grief. Mine was sat on an older version which probably didn't help matters.

From what I've seen knocking around other forums, Victron are aware and there's supposedly a fix coming — but no timeline that I can find. Might be worth keeping an eye on the Victron Community site directly rather than waiting for it to trickle down.

For now I've just got a local display wired in as a workaround. Not ideal but keeps me sane.

Sat with this exact problem for three days before I cracked it — and it wasn't the firmware itself causing the dropout, it was the Bluetooth scanning interval getting reset during the update.

After V3.80 installed on my Cerbo, it quietly reverted the BLE polling back to default, which on my setup meant the Small BMS NG kept falling outside the discovery window. Went into the Cerbo's Bluetooth settings, manually re-paired the BMS rather than relying on the cached device, and it's been rock solid since.

@ZFS_OffGrid worth checking whether yours is actually disconnecting or just appearing disconnected — the CCGX Remote Console sometimes shows stale status after an update cycle.

Running a Fogstar Drift 200Ah with the NG BMS here, so if anyone wants specifics on that particular pairing let me know.

Has anyone actually raised this with Victron directly? I've got a similar BMS setup in my static caravan and I'm wondering whether this is worth logging as a proper bug on the Victron Community forum before we all end up down rabbit holes.

@SolarJason what was the actual root cause if it wasn't the firmware itself? You've left us hanging there.

Also — is this specific to Bluetooth connection or does it affect anyone running the BMS wired via VE.Direct as well? Trying to work out whether switching connection method is worth the faff before I touch anything on my end.