ESS with 1 х MultiPlus 230V + MPPT + 3 х MultiPlus 400V like charger

Been mulling something similar over for my shepherd's hut project — currently running a single Victron MultiPlus-II 48/5000 for 230V loads alongside a SmartSolar MPPT 250/70, and it's working a treat. But I'm starting to wonder about scaling up.

The setup in question is interesting — using additional MultiPlus units configured for 400V three-phase as chargers only alongside a single-phase ESS inverter. Clever workaround on paper, but I'd be curious how the Victron ESS logic handles priority when you've got that mix of voltage configurations on the same DC bus.

A few questions worth thrashing out:

• Does the ESS assistant on the 230V unit play nicely when the 400V units are essentially acting as glorified bulk chargers?
• How are you managing feed-in — are the 400V units even visible to the GX device as part of the ESS?
• Any BMS comms complications? I'm running Fogstar Drift cells and the CAN bus integration is fussy enough with a simple setup.

My gut says you'd want everything talking to a Cerbo GX properly or the ESS optimisation goes out the window — it'll just do dumb charge/discharge cycles rather than proper grid interaction.

Has anyone actually bench-tested or deployed something like this in a UK domestic or semi-off-grid context? Would love to know if the VEConfigure side of it is as painful as I'm imagining. 🔧

@MrBodge65 a shepherd's hut with a 48/5000 is basically a very woolly data centre at this point 🐑⚡

@MrBodge65 a 48/5000 in a shepherd's hut is perfectly reasonable if you've sized it properly — assuming you've got the battery bank to back it up. What are you running for storage? If you're on Fogstar Drift cells you'll want to make sure your MPPT absorption settings aren't fighting your BMS. The 250/70 is a solid unit but it'll happily cook an undersized bank if your Victron parameters aren't dialled in through VE.Configure.

Also worth checking your minimum SOC settings in ESS — default 20% is useless for real off-grid use, I run mine at 30% to protect cell longevity.

@WattSue the "woolly data centre" comment is exactly the sort of thing that sounds clever until someone's sitting in the dark in February wondering why they went undersized.

@MrBodge65 similar boat (literally) — I run a Victron Multiplus-II 24/3000 on my narrowboat and the MPPT combo is solid once ESS is dialled in properly. Main thing I'd flag is keep an eye on your grid code settings if you're ever hooking into a hookup point — caught me out first time. Also worth checking your DVCC settings in VictronConnect before assuming the MPPT and Multi are talking nicely to each other. They usually are, but sometimes you need to prod them.

What's your battery setup? LiFePO4 or lead? Makes a difference to how aggressive you can be with the charge profile.

@BreezyDrifter the narrowboat connection is interesting — I went through something similar sizing for my static caravan before eventually landing on a MultiPlus-II 48/3000 paired with a SmartSolar MPPT 150/45.

What I found was that the MPPT and MultiPlus talk to each other beautifully once you've got them properly linked via VE.Direct and configured in VictronConnect — the system essentially self-manages around your battery state far better than you'd expect.

@MrBodge65 for a shepherd's hut the 48/5000 gives you lovely headroom, but do keep an eye on your idle consumption — that inverter draws a fair bit just sitting there. Worth checking your ESS minimum SOC settings carefully so you're not silently draining your bank overnight when loads are light.