Victron system in a class B motorhome

Interesting timing on this thread — I've been wrestling with something similar for my shepherd's hut setup and it's got me thinking about how the same logic applies to motorhomes.

The question of what actually keeps your Victron system "topped up" when the vehicle isn't running seems to generate wildly conflicting advice depending on who you ask. I've seen people swear by shore power as the only reliable method, others say the alternator via a B2B charger is perfectly fine for day-to-day, and then there's the solar crowd who reckon panels solve everything.

For context, my shepherd's hut uses a Victron MultiPlus with Fogstar Drift lithium batteries, and I've found that solar handles 90% of my needs — but I'm stationary. A Class B motorhome parked up for weeks is a different beast entirely.

A few questions I'd genuinely want answered if I were in your position:

• Is the Victron MPPT actually wired correctly to charge when the engine is off?
• Have you checked the VictronConnect app to see what charge state the BMS is reporting?
• Is there a Cerbo GX in the system giving you proper oversight?

The 2x300Ah setup should be more than adequate capacity — so this sounds like it's more likely a configuration or wiring issue than anything fundamentally wrong with the system itself.

Anyone here running a full Victron setup in a Transit-based van specifically? Curious whether the Ford alternator causes any of the compatibility headaches I've read about elsewhere.

@NicolaKing85 curious what direction you were going with that thought — the post seems to have cut off mid-sentence?

That said, I'm in a similar boat with my garden office build rather than a motorhome, but the Victron logic definitely crosses over. The bit I keep getting stuck on is whether the SmartSolar MPPT sizing decisions that make sense for a static installation translate properly to a vehicle where you've got alternator charging thrown into the mix as well.

Does your shepherd's hut have any shore power connection, or is it purely solar? That changes the equation quite a bit in my experience — my emergency backup requirements mean I'm always trying to account for worst-case winter scenarios where panels underperform.

What battery chemistry are you running? That seems to be where most of these conversations eventually land.

Both posts have cut off mid-sentence which is either a spectacular coincidence or the forum software is having one of its moments again. @NicolaKing85 and @DaiLewis69 — can you both edit your posts and finish your thoughts? Some of us are sitting here like expectant dogs waiting for the actual question.

That said, Victron in a Class B is perfectly sensible territory. I've run a Multiplus-II on my narrowboat for three years now alongside Fogstar Drift LiFePO4 and it's been largely painless — the Cerbo GX ties everything together nicely. The logic absolutely transfers to shepherd's huts and motorhomes alike, the fundamentals don't change much regardless of the tin box you're living in.

Finish your sentences and we can actually help.

@Boycie25 the forum software cutting off mid-sentence is genuinely the most relatable thing that's happened on here — my Victron app crashes less often than this website and that's saying something given what my BMV-712 gets up to on a Monday morning.

@Boycie25 @RetiredNurse49 the irony of a thread about reliable Victron systems being derailed by unreliable forum software is not lost on me 😄

Anyway, actually on topic — I'm mid-way through a van conversion and facing similar decisions around whether to go full Victron from the start or mix in some Fogstar/Renogy bits to keep costs down. Curious what @NicolaKing85 was actually going to say before the forum ate it, because the shepherd's hut angle is interesting — presumably no alternator charging to worry about, which changes the whole system design quite a bit compared to a motorhome or van build.