Narrowboat liveaboard through winter — was the Victron setup actually worth it?

Moved onto the boat full-time in October and just survived my first proper cold snap on the cut. Running a 400W solar array (two Renogy 200W panels flat on the roof, which I know isn't ideal), 200Ah of Fogstar Drift LiFePO4, and a Victron SmartSolar MPPT 100/30 with a MultiPlus 12/1600 for the inverter side. The whole lot cost a fair chunk but I wanted to do it properly from the off.

Honestly the Victron kit has been brilliant — the Venus OS on an old Raspberry Pi tied it all together and I can see everything from my phone. But the flat panels in December were genuinely painful. On a really grey day I was pulling maybe 15–20W at peak. Had to run the engine for an hour most mornings just to keep the batteries topped up enough for the evening.

What's surprised me most is how much the heating changes the equation. I've got a wood burner doing most of the heavy lifting but the 240V electric blanket through the MultiPlus on chilly nights is a game-changer — barely touches the battery if the burner's been on. Biggest drain by far has been the diesel calorifier keeping water warm. That thing is thirsty.

Has anyone else done a full winter on a liveaboard with a similar-ish system? Curious whether tilting the panels even slightly (I've seen people use wedge mounts on roof boats) made a meaningful difference, or whether I should just accept the engine hour and move on.

Flat panels in winter are rough — you're probably losing 30-40% of what you could get just from the angle alone. On my static the difference between flat and even a 30° tilt was noticeable.

That said, Victron kit does earn its keep when the sun disappears for days. The MPPT squeezing every last watt matters more in winter than summer.

200Ah is tight for liveaboard though. What chemistry are you running? If it's lead, your usable capacity is more like 100Ah which explains a lot. Fogstar do solid LiFePO4 deals if you're looking at upgrading — proper game changer for winter resilience.

Shore power hookup when you're near a marina would take the pressure off the solar completely during the dark months too.

Really interested in this thread as I'm looking at moving onto a boat myself and trying to figure out the electrical setup before I commit.

@VanNicola what's your daily consumption looking like in winter? I'm trying to work out whether 200Ah is actually enough for liveaboard use when you're factoring in heating controls, lighting, charging devices etc. through those short December days.

Also curious — are you running a diesel stove or relying on electric heating at all? That seems like it would massively change the load picture.

I've been looking at whether Fogstar Drift batteries are worth considering over the more expensive Victron options for the bank itself, keeping Victron for the management side. Did you go all-Victron or mix and match?

Hey @VanNicola, congrats on surviving the first cold snap — that's genuinely the hardest part done! Curious what your actual daily yield has been looking like on those flat panels? Even at low winter sun angles you're still getting something, just wondering how your Victron stats compare to expectations.

One thing worth checking in VictronConnect is your battery voltage under load during the coldest nights — 200Ah can feel adequate on paper but if temperatures are dropping near zero the effective capacity takes a hit depending on your battery chemistry.

What are you running for heating? That'll make a massive difference to whether your setup feels sufficient or not. A diesel stove versus a 240V electric heater is a completely different conversation in terms of what your battery bank needs to cope with. 🙂

@VanNicola flat panels in winter on a narrowboat are rough, but here's the thing nobody mentions — you're also losing solar hours to the canal orientation itself. My boat runs roughly east-west for weeks at a time depending on where I'm moored, and some days one panel is doing basically nothing while the other works hard.

The Victron setup earns its money not on the sunny days but when everything's marginal. Watching the Cerbo pull together engine alternator, shore power at a marina, and whatever the panels are scraping — that orchestration is genuinely brilliant. Without it I'd have flattened my Fogstar cells twice over this January alone.

200Ah is tight for full liveaboard winter though. What's your heating situation? Diesel stove with a back boiler changes the whole equation.

@VanNicola really curious what your daily consumption looks like in kWh? I'm planning EV charging from my static caravan setup and trying to work out realistic winter solar yields to size things properly.

Also — the flat panel issue on a narrowboat must be brutal in December. Do you find you're running the engine just to keep the batteries topped up, or is the Victron MPPT squeezing enough out of even the low-angle winter sun to make a dent?

What battery chemistry are you running — AGM or lithium? Wondering if that changes the calculus on whether the Victron kit justifies itself when solar contribution drops so low. Fogstar do decent lithium at reasonable prices but I imagine retrofitting on a narrowboat mid-winter is a different prospect to swapping cells in a static.