DESS Does not reset Battery Balancing issue, after more than 3 days of balancing

So I've got a bit of a head-scratcher on my hands and wondering if anyone else has run into this.

Running a Victron setup out in my shepherd's hut — MultiPlus-II, SmartShunt, and a bank of Fogstar Drift lithium cells managed through a Cerbo GX. About three weeks ago the VRM portal flagged that battery balancing was scheduled, which was fine, expected it actually given the cells had been sitting slightly out of balance since I added the fourth battery earlier in the summer.

The balancing ran — or at least appeared to run — over a long weekend. Problem is, it's been well over three days now and the VRM portal is still showing the balancing notification. The DESS (Dynamic ESS) hasn't cleared it or reset back to normal scheduling behaviour. Everything else looks functionally fine — SOC is reading sensibly, the cells aren't wildly divergent anymore — but that notification is just... hanging there like a bad smell.

A few questions for the collective wisdom here:

• Has anyone seen DESS fail to acknowledge that balancing has completed and just get stuck in this state?
• Is there a way to manually force a reset of the balancing flag through VRM or the Cerbo console without losing other settings?
• Could this be a firmware issue? I'm on the latest Venus OS stable release but haven't checked whether there's a known bug logged anywhere.

I'd rather not do a full DESS reconfiguration if I can avoid it — took me long enough to dial it all in around my grid export tariff. Any pointers gratefully received.

Seen something similar with my tiny house setup. DESS can be a bit stubborn when the cells are genuinely out of balance — it won't just reset the flag because time's passed, it needs to actually see the balance condition met.

Few things worth checking:

• Is your SmartShunt seeing full charge cycles? DESS needs proper tail current detection
• Check your absorption voltage is actually hitting all cells consistently
• VRM logs — worth pulling them to see what DESS thinks the SOC history looks like

Also, Fogstar Drift cells or the older ones? Had weird balancing behaviour with a mixed batch once, turned out one cell was just a bit dodge.

What's your absorption voltage set to and how long are you holding it? Sometimes bumping dwell time sorts it without needing to faff with DESS directly.

@SolarNeil had this exact thing with my Fogstar Drift cells last winter in my hut. Took ages to sort.

One thing worth checking — is your SmartShunt actually seeing full charge cycles? If you're in a low-sun period and never hitting absorption properly, DESS just keeps waiting. It needs a proper 100% SOC reset to clear the flag.

Also worth looking at your Minimum SoC setting in the ESS assistant. Had mine set too conservatively and it was preventing the balancing cycle from ever completing.

Try forcing a manual full charge on a decent day and see if it clears. VRM should show you whether absorption is actually being reached or just approximated.

Has anyone actually checked whether the BMS is actively balancing during those 3 days, or just reporting that it needs balancing? Because on my boat setup I had a similar saga where the Victron DESS kept flagging the issue but the BMS had quietly given up balancing due to a dodgy cell-level voltage reading.

Worth pulling the raw cell data from your BMS if you can — not just the SmartShunt figures. The SmartShunt only sees pack-level voltage, so it can't tell you which cell is dragging everything down.

Also — what's your absorption voltage set to? If it's slightly low, the cells might never actually hit the threshold needed to trigger proper top-balancing. Been bitten by that one before on the garden office setup.

What BMS are you running with those Fogstar cells specifically?

@DodgyMechanic raises the exact right question. I spent three weeks chasing a similar ghost last autumn — turned out my BMS was reporting active balancing but the actual cell delta hadn't shifted more than 10mV across the entire period.

The story that unfolded: VRM logs showed the SmartShunt's voltage history was perfectly flat, which told me the passive balancer resistors on the BMS were never actually dissipating heat. Touched the board — stone cold. Balancing was essentially disabled at the firmware level despite showing "active."

Check your BMS companion app (if Daly or JK, they both have live cell voltage screens) and watch individual cell voltages in real-time during absorption. If the weakest cell isn't slowly converging toward the others over 30-60 minutes, your balancer isn't firing regardless of what DESS reports.

Force a manual top-balance with a bench PSU if needed — DESS cannot fix a hardware/firmware issue.

Good shout from @DodgyMechanic and @TorJake — this is often the crux of it.

One thing worth checking that nobody's mentioned yet: have you verified your absorption voltage is actually reaching the cells properly? If your MultiPlus-II absorption setpoint is even slightly under what the BMS needs to trigger active balancing, the cells will sit there looking like they're being balanced when actually nothing's happening.

With Fogstar Drift cells specifically, I'd also double-check your absorption duration settings in VictronConnect. The default adaptive absorption can cut out earlier than you'd expect if the tail current drops off quickly, leaving balancing incomplete.

What voltage are you seeing at the battery terminals during absorption? Worth comparing that against what the SmartShunt is actually reporting — any meaningful difference could point to a wiring resistance issue further upstream.