Generator working better on a Multi RS (solar) compared to MP 2?

Curious whether anyone's noticed a difference in generator performance between the Multi RS Solar and the Multiplus II?

Background: on the boat I run a 6kVA Victron-recommended generator into a Multiplus II 48/5000/70, and I've never managed to squeeze more than roughly half its rated charge capacity out of it. The PowerAssist and transfer switch side of things work fine, but actual bulk charging from the genny feels like it's leaving a lot on the table. I've fiddled with the AC input current limit in VictronConnect until I'm blue in the face — no dramatic improvement.

Now I'm wondering if this is a Multiplus II quirk, or just generator harmonics being awkward. Someone in a Facebook group mentioned their Multi RS seemed to cope noticeably better with a similar-sized general purpose generator — apparently the RS handles "dirty" AC more gracefully?

A few questions for the collective wisdom here:

• Has anyone run a standard non-inverter generator (so not a Honda EU-series type) into a Multi RS Solar and actually hit close to full charge rates?
• Is this a real difference in how the two units handle AC input quality, or is it more about wiring, earthing, and the usual narrowboat/van gremlins?
• Would the RS even make sense as a straight swap if you're not massively solar-heavy?

I'm considering adding more panels to the van conversion project anyway, so the RS is on my radar — but if it also solves the generator headache on the boat that'd be a nice bonus. Might be wishful thinking though. 😄

Anyone gone down this road?

@CornishCruiser yes, this is a real and documented difference. The Multi RS uses a fundamentally different AC input architecture — it's a hybrid inverter design rather than the traditional transformer-based topology of the MP2. The RS's input current sensing and power assist algorithms are noticeably more tolerant of "soft" generator output (high THD, voltage sag under load). On my narrowboat with a Fischer Panda, the RS Solar locked on and charged cleanly where a borrowed MP2 kept nuisancing on overload.

Key thing to check: make sure UPS function is disabled in the RS settings when running generator — it's far less fussy about waveform quality with that off. Also verify your generator's shore current limit is set conservatively (I run mine at 80% nameplate).

What's your generator brand? Some of the cheaper Königs and Hyundais struggle with any Victron kit regardless.

@ExSquaddie49 interesting — so is this something Victron have actually acknowledged, or is it one of those "works in practice, don't ask us why" situations that seem oddly common with their kit? 😄

On my narrowboat I've been dithering between the two units for my emergency backup setup. The generator compatibility angle is actually a big factor for me since marina shore power is... let's say optimistic at best, and I'd be leaning on the genny more than I'd like.

Does the Multi RS's superior generator handling extend to smaller, cheaper units too, or is it mainly beneficial with the Victron-recommended inverter generators? Asking because I'm not exactly rushing to spend £££ on a matched generator if a decent Hyundai or similar would behave itself.

@ExSquaddie49 curious about this too — not on a boat but running a Honda EU22i into a Multi RS at the cabin and it's noticeably smoother than when I had a MP2 in the same spot. Less hunting, cleaner handoff when solar drops off in the evening.

Always assumed it was just the Honda being a decent genny but sounds like there's more to it. Would be good to know if Victron have it in writing somewhere — @SunnyFisher that's the question isn't it, whether it's documented or just anecdotal from enough installs that it becomes accepted wisdom.

Anyone got a Cerbo log comparison between the two setups?

@DeclanKnight57 the EU22i is an inverter generator so it's already producing clean AC — the Multi RS input architecture shouldn't be causing you grief there. More likely culprit is your UPS mode setting or the PowerAssist configuration. What's your AC input current limit set to?

On the broader question — yes, Victron have documented the Multi RS's different AC input handling. It uses a high-frequency topology rather than the MP2's transformer-based approach, which changes how it interacts with generator waveforms. In practice this means some generators that cope fine on an MP2 struggle on the RS.

Running a Victron-recommended Whisperpower on my shepherd's hut setup through an MP2 and it's rock solid. Wouldn't switch to RS specifically because of this — transformer-based units are more generator-tolerant in my experience, full stop.

@DeclanKnight57 had the same with a Honda EU22i into my Multiplus II on the static — always felt like it was fighting it a bit. Swapped the setup around last year and the RS is noticeably smoother on acceptance.

Worth checking your UPS function settings and input current limit in VEConfigure if you haven't already — sometimes the MP2 is just being overly cautious rather than it being an architectural thing. That sorted a chunk of my issues before I even changed units.

That said I do think @SolarJunkie is onto something — the RS input stage just seems more tolerant in practice, whatever the specs say on paper.