Victron Multiplus tripping out when the washing machine hits its heating cycle

Had this exact issue last summer with my shepherd's hut setup. The Multiplus 12/3000 would trip the moment the washing machine's heating element kicked in — classic inrush current problem rather than a sustained overload.

Few things worth checking:

1. PowerAssist settings
If you're running shore power or a generator alongside, make sure PowerAssist is actually enabled in VictronConnect. It lets the inverter draw from both sources simultaneously to cover those spike loads.

2. Dynamic Current Limiter
Enable this in the settings. It tells the Multiplus to be more forgiving about brief current spikes rather than tripping immediately.

3. Battery state and cable gauge
A battery that's below ~50% SOC will sag under load, which the inverter interprets as an overload condition. Also worth checking your DC cable runs — voltage drop on undersized cable can trigger the same behaviour. I was running 35mm² initially and upgraded to 70mm² which made a noticeable difference.

4. Which Multiplus exactly?
The 12/3000 is borderline for a washing machine with a full heating element — some machines pull 2,200W sustained during the heat cycle. The 24V or 48V versions handle this more gracefully. Worth looking at your machine's actual rated wattage rather than the drum capacity.

What battery chemistry are you running? LiFePO4 will handle the discharge spikes far better than AGM. My Fogstar Drift cells barely flinch at 150A draw whereas my old Trojan AGMs used to sag badly.

What does your VRM portal or the Multiplus LEDs show when it trips — is it the overload indicator or the low battery warning lighting up?

@BatteryBarry the "rather than" is doing a lot of heavy lifting there, mate — did your post get eaten by inrush current too? 😄

Jokes aside, check your AC input current limit in VictronConnect — if it's set too conservatively, the Multiplus will keel over the moment anything remotely demanding kicks in. Also worth enabling PowerAssist if you haven't already; it lets the inverter pull from the batteries to bridge that spike rather than just sobbing and giving up.

On the shepherd's hut, I run mine with PowerAssist set just right and a Fogstar 200Ah lithium — handles the spin cycle no bother. The heating element is the real villain here, not the motor.

What's your battery bank and the transfer switch speed set to in the settings?

@BatteryBarry @LochLover — assuming the post got eaten mid-sentence, I'll fill in the likely conclusion: it's almost certainly a sustained overload rather than pure inrush, because the Multiplus handles inrush reasonably well via its PowerAssist function. The heating element is the culprit — a typical 2kW element on a 12V system demands roughly 167A continuous from your batteries.

Check your Multiplus configuration in VE.Configure — specifically the "AC Input current limit" and inverter assist settings. Also worth examining whether your PowerControl threshold is set correctly. What's your battery bank capacity and chemistry? A 12/3000 on a small lithium bank with conservative BMS limits will trip under that sustained load well before the inverter itself reaches its ceiling.

@DefenderAdventure you're doing the same thing mate 😄

Right, let me actually finish a thought for once — the key thing worth checking here is whether the Multiplus is configured correctly in VictronConnect. The default transfer switch settings can be quite conservative, but more importantly, have a look at your AC input current limit and the PowerAssist settings.

Also worth knowing: the 12/3000 at 12V is working considerably harder than a 24V or 48V equivalent to deliver the same wattage, so your battery cables and connections need to be absolutely spot-on — any resistance there will compound the voltage sag during inrush and push the unit into low voltage shutdown before the protection even trips on overcurrent.

What battery chemistry are you running? Lithium handles that instantaneous demand far better than AGM in my experience.

@IanWilson86 genuinely crying at this thread — nobody can finish a sentence 😂

Right, actual question though: is anyone actually checking the transfer switch timing on the VE.Config settings? My 2000/12 in the van used to do something similar and dropping the UPS function made no difference — turned out the AC input current limit was set too conservatively and it was trying to switch sources mid-cycle rather than just inverting through it.

Also worth checking: is the washing machine running on inverter-only or is there shore/generator input involved? That changes the diagnosis completely. If it's pure inverter mode and still tripping, what does VictronConnect show for the fault code? There's a difference between overload and low battery cutoff and people often conflate the two.