Anyone else had grief with a Victron MultiPlus 2 tripping on generator input? Mine keeps dropping out

So I've finally got my off-grid setup mostly sorted — 8kWh of lithium (SOK 206Ah batteries), 2.4kW of solar on the roof, and a Honda EU22i generator for backup and winter top-ups. The MultiPlus 2 (24V, 3000VA) has been brilliant on solar, but the moment I fire up the Honda and try to charge through it, it trips out within a few minutes. No load on the inverter at the time, just trying to do a straight AC charge.

The error I'm getting is a "VE.Bus Error 11" — grid relay test failure. I've had a read through the Victron docs and there's talk about AC input voltage and frequency tolerances, but the Honda's supposed to put out a clean 230V/50Hz. I've got the input current limit set to 10A in VEConnect which should be well within what the generator can handle (it's rated 2200W continuous). Tried dropping it to 8A, same issue.

Wondering if anyone's run a MultiPlus alongside a Honda EU22i specifically, or had similar VE.Bus errors on generator input. Is this a known issue with inverter-generators and the MultiPlus? I've seen some chat about the PowerAssist settings potentially causing havoc but I'm not sure where to start.

AndyPalmer | Posts: 847

@Stacey72 the EU22i is an inverter generator so its frequency can wander a bit under load, which the MultiPlus can be quite fussy about. First thing I'd check is your UPS function setting and the AC input current limit in VEConfig — if it's set too low the MultiPlus will constantly fight the generator trying to draw more than it's allowed.

Also worth looking at the dynamic current limiter setting. Tick that box if you haven't already — it tells the MultiPlus to be more forgiving with inverter generators that take a moment to respond to sudden load demands.

What firmware version are you running? There were some known issues with generator compatibility on older builds that Victron quietly sorted out.

SimonJohnson67 | Posts: 134

Had almost identical grief with my narrowboat setup. Worth checking the weak AC input setting in VEConfig — there's an option to tell the MultiPlus the generator is a weak source, which makes it far more tolerant of voltage/frequency wobbles.

Also, what's your input current limit set to? The EU22i is only rated ~8A continuous at 230V, and if the MultiPlus tries to pull more than that during bulk charging it'll drag the generator down and trip. I keep mine set to 7A to give it headroom.

One other thing — are you running the generator under any significant load when it trips, or even at idle? That'll help narrow down whether it's a frequency issue or an overload situation.

Chalky38 | Posts: 312

@Stacey72 one thing nobody's mentioned yet — have a look at your input current limit setting in VEConfigure. If it's set too low, the MultiPlus will try to pull more than the Honda can comfortably deliver and you'll get that exact dropping-out behaviour, especially once the batteries are hungry and it's charging hard.

The EU22i is rated at roughly 10A at 230V, so I'd set the input limit to around 8A to give yourself some headroom. The MultiPlus will then manage its charging current accordingly rather than flogging the genny.

Also worth enabling PowerAssist if you haven't already — lets the inverter supplement the generator when loads spike rather than the whole thing collapsing. Made a big difference on my setup. What firmware version are you running?

DalesSolar | Posts: 2,156

@Stacey72 good shout from @Chalky38 on the input current limit — that's caught me out before too. One thing I'd add: check your AC input voltage and frequency acceptance window in VictronConnect. The MultiPlus 2 defaults can be surprisingly fussy. Try widening the frequency range to something like 45–65Hz and voltage tolerance down to around 180V. The EU22i is a cracking little genny but it's not always perfectly stable under varying load conditions. Also worth looking at whether your shore power transfer switch settings are causing premature dropout. Sometimes it's not the generator at fault at all — the MultiPlus is just being overly cautious. Have a poke around in the assistant settings too if you've got any programmed. What firmware version are you running?

LazyRanger | Posts: 203

My van MultiPlus 2 threw the same tantrum until I turned UPS mode off in VE.Configure — apparently it makes the thing far less precious about dodgy AC waveforms, which inverter gennies basically are by definition. Also worth lobbing a Hook-up Stabiliser (some call it a voltage optimiser) between the Honda and the MultiPlus if the above doesn't sort it; saw that tip on Victron's own community forum and it genuinely helps with frequency wobble. @AndyPalmer, @SimonJohnson67 and @Chalky38 have already covered the sensible stuff, so I'm just here adding the slightly unhinged extra steps that van life eventually teaches you.

DorsetExplorer | Posts: 847

@Stacey72 welcome to the forum! Great first setup by the way — SOK + Honda is a solid combo 👍

One thing worth checking that nobody's mentioned yet — the AC input voltage range in VE.Configure. The EU22i can wobble a bit on frequency and voltage under load, and if your MultiPlus tolerance is set tight it'll trip immediately. Widening the acceptable range (lower minimum voltage, broader Hz tolerance) sorted exactly this on my motorhome build. Takes 2 mins in VE.Configure once you're connected via MK3 cable.

WillStevens | Posts: 847

@Stacey72 one thing worth checking that nobody's touched on yet — the Honda EU22i's AVR can sometimes produce a slightly wobbly waveform under load, particularly when it's cold or the throttle hasn't fully stabilised. The MultiPlus 2 has a fairly tight voltage/frequency acceptance window by default.

In VE.Configure, have a look at AC Input voltage range and frequency limits under the inverter tab — you can widen these a touch to give the generator a bit more tolerance. Don't go mad with it, but loosening them slightly often sorts nuisance trips without compromising anything meaningful.

Also worth letting the Honda warm up and settle at idle for a minute or two before the MultiPlus tries to sync with it. Sometimes that alone makes a big difference with inverter-generators.

BaySoul | Posts: 412

Had identical drama in my motorhome — turned out the MultiPlus 2 was set to accept a wider voltage window than the little Honda could actually hold under load, so it was basically watching the genny wave goodbye every time the kettle kicked in. Check your AC input voltage range in VE.Configure; bumping the lower limit down to around 180V stopped mine throwing its toys out completely.