Quattro behaving badly

My Quattro 48/5000 decided last winter that its favourite hobby was throwing AC input errors every time a cloud looked at my solar panels funny — turns out the BYD batteries and the Quattro were having a proper domestic because the DVCC settings were configured like someone had thrown darts at the screen whilst blindfolded.

Three things that sorted mine out (and might save your sanity):

• DVCC shared current sense — make absolutely sure this is enabled and that your GX device is actually talking to the batteries properly via CAN-bus, not just pretending to
• AC input current limit — if you're on shore power or a generator, an undersized limit here will make the Quattro sulk dramatically
• Battery monitor assignment — had mine set to the wrong device entirely for two months, which explained everything

Living on a boat means grid disturbances are basically a daily adventure, so the Quattro does get a rougher ride than a static install — but even accounting for that, Victron's VictronConnect logs are genuinely brilliant for diagnosing what exactly went wrong at 2am when you were asleep.

What firmware are you running? There were some right gremlins in a couple of releases last year that caused similar grief with the BYD LV modules specifically.

Also worth posting your setup on the Victron Community forum — those lot are frighteningly knowledgeable and will spot something in your screenshots within about four minutes flat.

What does your grid AC waveform look like? Worth checking with a cheap power analyser — dodgy shore power supplies have caused me tremendous drama in the past.

@MarineKaren the BYD/Quattro comms issue is well-documented — make sure your DVCC settings are actually doing something. A lot of people enable it and assume that's sufficient, but if the BYD BMS firmware isn't on a compatible version the Quattro is essentially flying blind on battery state and starts making panicked decisions about AC input.

Check your VE.Bus System Configurator logs — specifically look for whether it's throwing #8 (AC input voltage out of range) or #10 (battery voltage too high/low). They present similarly but have completely different fixes.

Also worth checking: what's your AC Input current limit set to? If it's too conservative relative to your inverter load, the Quattro will hunt between grid and inverter mode constantly, which looks like an AC input fault but isn't really.

@MarineKaren had almost identical grief on the narrowboat last winter — Quattro 48/8000 throwing fits every time the solar fluctuated. Turned out my ESS assistant was configured too aggressively on the AC input current limit, so the moment grid (or in my case the shorepower) wobbled, it panicked.

Worth checking:

• Grid setpoint in ESS — if it's chasing too tight a target it'll oscillate
• Weak AC input checkbox in the Quattro config
• AC input voltage window — widen the acceptable range in VEConfigure if your supply is wobbly

@SomersetVanLifer is right about DVCC, but I'd also look at whether your VE.Bus firmware is current. Victron pushed some updates last year specifically addressing BYD stability. Run VictronConnect and check — mine was embarrassingly out of date when I finally looked.

@MarineKaren had a similar saga with my van setup — not a Quattro, but the lesson was the same. The Victron gear is brilliant right up until it isn't, and when it decides to have a tantrum it does so with absolutely no sympathy for the fact that it's February and you're running on a generator in a layby somewhere near Carlisle.

One thing nobody's mentioned yet — check your AC input voltage thresholds in VEConfigure. Mine were set far too tight from factory, and anything slightly wobbly from the grid or genny would send it into a sulk. Widening those tolerances sorted about 60% of my grief before I even touched the DVCC settings.

It won't solve everything but it's a five-minute job worth doing first before you start pulling your hair out over BYD comms.

@MarineKaren one thing worth checking that nobody's mentioned yet — have a look at your AC input current limit settings in VEConfigure. If it's set too low, the Quattro can get itself into a right muddle when solar output fluctuates and it's trying to balance the load. Also worth checking whether your grid code settings match what you're actually connected to — a mismatch there can cause phantom AC input faults that look completely unrelated to the real problem. What firmware version are you running on the Quattro? There were some known issues in older builds that caused erratic behaviour specifically with BYD battery systems, and a firmware update sorted it for a few people I know. Might be worth logging a few days of data through VRM if you haven't already — the patterns in the graphs can be really telling.