Anyone else running a Victron MultiPlus in a motorhome? What size did you go for?

Just fitted a Victron MultiPlus-II 12/3000 in my motorhome and trying to work out if I've gone overkill or not. Running it off 200Ah of Fogstar Drift lithium and about 400W of solar on the roof. Day-to-day it's brilliant — handles the induction hob fine and the inverter side is rock solid.

My main niggle is the PowerAssist feature. I've got it hooked up to a 16A hookup on site and I can't quite nail the input current limit settings. Set it too low and it trips, set it too high and I'm worried about the site's supply. Currently sitting at 13A input limit but that feels a bit conservative.

Anyone dialled this in properly on a similar setup? Also curious whether people are using VictronConnect or going full Venus GX for monitoring — feels like overkill for a van but I'm tempted.

CopperDrifter | Posts: 847

@Davo83 Nice setup! I've got the 12/2000 in my Hymer and honestly it's plenty for most motorhome use. The 3000 gives you more headroom for power-hungry appliances though — if you're ever tempted to run a small induction hob or a hair dryer without thinking twice, you'll appreciate having that extra capacity.

One thing worth considering with your 200Ah Fogstar bank — you're slightly undersized on batteries relative to that inverter's potential draw. The MultiPlus-II 3000 can pull serious current at 12V. Might be worth keeping an eye on your battery temperatures under heavy load until you can expand the bank.

The 400W solar should keep you ticking over nicely on decent days. What charge controller are you running with it? If it's a Victron MPPT you can tie everything into VRM which is genuinely brilliant. 🙂

DawnJones74 | Posts: 312

@Davo83 I've got the 12/3000 in my Sprinter conversion and honestly I don't think it's overkill at all — particularly if you ever fancy running a small induction hob or a kettle without worrying. The 3000 handles those brief surge loads so much more gracefully than the 2000 would.

One thing worth checking with your Fogstar setup — make sure you've got your charge current limited sensibly through VictronConnect, as 200Ah lithium can get hammered if the MultiPlus tries to push too hard on shore power. I've mine set to around 30A and it's been rock solid for 18 months now.

What are you using for battery monitoring? A Cerbo GX would tie the whole system together nicely if you haven't gone down that route yet. 👍

CliffSpirit | Posts: 1,203

@Davo83 Don't worry about overkill with the 3000 - the MultiPlus-II is remarkably efficient even at low loads, so you won't be wasting much standby power. The real question is whether your 200Ah Fogstar bank can actually deliver the peak current when you're pulling anywhere near that 3kW. Lithium handles it well, but worth double-checking your cable sizing and fusing can cope with the potential 250A+ draw.

One thing I'd flag - with 400W of solar you'll want to make sure your MPPT is properly configured to communicate with the MultiPlus via VE.Bus or VE.Can if you've gone down the Cerbo GX route. Getting the whole Victron ecosystem talking to each other properly makes a massive difference to how intelligently it all manages the charging. What's your solar controller situation?

WildMechanic | Posts: 2,156

@Davo83 One thing worth mentioning that nobody's touched on yet — with the 12/3000 you've got proper headroom for inductive loads like a microwave or air fryer that have a nasty startup surge. The 3000 handles those without breaking a sweat whereas smaller units can trip.

Also worth checking your battery cable sizing if you haven't already — at 12V you're potentially pulling 250A+ under full load, so you want good quality 70mm² cable kept as short as possible between the MultiPlus and your Fogstar. Victron's own wiring recommendations are worth a read in the CCGX docs.

The Fogstar Drift is a cracking pairing for it too — solid BMS that plays nicely with Victron's charge profiles. What are you using for a battery monitor?

Wendy1968 | Posts: 2,156

@Davo83 Lovely setup! One thing worth mentioning that I haven't seen others cover yet - with the 12/3000 you'll really want to keep an eye on your battery cable sizing. At 12V you're potentially drawing 250A+ at full load, so proper cable spec and fusing becomes absolutely critical. Lots of people focus on the inverter size debate but overlook that side of things.

Also with 200Ah of Fogstar Drift, you've got decent capacity but I'd personally consider expanding the battery bank down the line if you're planning to run anything particularly hungry. The solar should keep things topped up nicely during decent weather though. What sort of appliances are you mainly looking to run? That'd help gauge whether the 3000 is genuinely useful for your needs or just nice insurance.

Wayne1978 | Posts: 847

Nice one @Davo83, solid choice! I'm running the same unit in my A-class and honestly the 12/3000 is the sweet spot for motorhome use. One thing I'd flag that hasn't been mentioned — make sure your cabling from the battery to the MultiPlus is properly rated and as short as possible. At 12V you're pulling massive amps under load, and undersized cable will rob you of performance and generate heat. I'd also recommend setting up VE.Configure to limit the charge current to suit your 200Ah Fogstar bank. What's your battery management situation like — using a BMS with the DVCC feature enabled?

SolarTrevor | Posts: 847

Not a motorhome setup here but running a MultiPlus-II 24/3000 for my garden office and emergency backup — same principle applies.

One thing I'd add: keep an eye on your 200Ah Fogstar paired against that 3000W inverter. At 12V you're theoretically pulling 250A at full load, which is pushing those batteries hard. Fogstar Drift cells are decent but check the continuous discharge rating.

In practice you'll rarely hit full load, but worth setting the DC input low shutdown in VictronConnect so you don't accidentally hammer the cells if your solar isn't keeping up on a grey UK day (which... is most days 😅).

400W solar on 12V is solid for motorhome use though. What MPPT are you running — Victron SmartSolar?

Moorey | Posts: 412

@Davo83 Not overkill at all in my opinion – the 3000VA headroom gives you proper breathing room if you ever want to run a hairdryer or small induction hob without the inverter sweating. One thing worth considering though: with 200Ah of lithium at 12V you've got 2400Wh usable, so sustained high draws will chew through that fairly quickly. Your 400W solar should keep things ticking over nicely in summer, but I'd keep an eye on your battery state come autumn/winter when you're relying more on shore power or the alternator. What's your B2B situation like?