Victron Multiplus keeps switching to passthrough at night — anyone else had this?

Had this exact saga on my narrowboat last winter. Drove me absolutely mental for about three weeks before I tracked it down.

Turned out my Dynamic Current Limiter was enabled and causing the Multiplus to essentially panic at perceived load spikes overnight — things like the fridge compressor kicking in, combined with a slightly saggy connection on the shore power lead. The unit would decide passthrough was safest and just... stay there.

Few things worth checking:

• Input current limit — is it set appropriately for your supply? Mine was set too conservatively
• AC input voltage tolerance — widen it slightly in VE.Configure if your shore power is wobbly
• Battery voltage thresholds — if your bank is undersized or your BMS is being twitchy, the Multiplus will interpret that as a reason to lean on shore power

I'm running a 200Ah Fogstar Drift LiFePO4 bank with a Multiplus 12/3000 and the settings interaction between the BMS comms and the inverter took me ages to get right. The Victron Connect logs were genuinely invaluable — download them and look for the exact moment it switches. The reason code is usually buried in there.

Also worth checking: is your VE.Bus BMS or any connected DVCC device sending an "allow to charge/discharge" signal that might be cutting out intermittently?

What's your setup — LiFePO4 or AGM? And are you on shore power or solar at night? Makes a big difference to where the fault's likely hiding.

@StormySocket interesting one — I've got a Multiplus on the motorhome and haven't hit this specific issue yet, but want to make sure I understand the failure mode properly before it bites me.

When the Dynamic Current Limiter kicks in like that, is it purely a load-sensing thing, or does battery state of charge factor into the decision at all? I'm trying to work out whether it would behave differently depending on whether I'm hooked up to a weak hookup post versus running from my Fogstar lithium bank overnight.

Also — was this configurable through VictronConnect or did you need VEConfigure/VE.Bus System Configurator to actually disable it? I've only got Bluetooth access to mine at the moment, no MK3 interface yet.

@StormySocket this is timely — I've been scratching my head over something similar on my boat. Mine's doing it intermittently rather than consistently at night, which almost makes it harder to diagnose.

Quick question before I go pulling settings apart in VE.Config: does the Dynamic Current Limiter issue only show up once the batteries drop below a certain state of charge, or can it trigger regardless? Mine's got Fogstar Drift lithium cells so I'd expect the voltage to stay relatively stable, but I'm wondering if there's a threshold I should be checking in the assistant settings.

Also — was yours connected to a shore power hookup when it happened, or purely on battery/inverter mode? Trying to narrow down whether mine's a similar root cause or something else entirely.

@12V_King intermittent is the worst kind of fault — the one that vanishes the moment you're staring at it with a multimeter in hand, like some kind of electrical poltergeist.

Worth checking your AC input voltage logs in VictronConnect. I had a similar haunting on my backup system — Multiplus going into pass

@12V_King intermittent faults on a narrowboat are basically a subscription service you never asked for. Mine once took three weeks to reappear — long enough that I'd convinced myself I'd imagined the whole thing and briefly considered therapy.

What sorted it for me was leaving VRM logging running overnight for a solid week. Caught the exact moment the