Victron product suggestion

Been down this rabbit hole myself when I was speccing out the power system for my tiny house build last year, so thought I'd share what I landed on.

If you're pulling a fairly modest 17A at 48V from a LiFePO4 bank, the question isn't just which Victron product — it's really about what that downstream device needs. Is it expecting clean regulated DC, or are you just passing battery voltage through?

For most scenarios like this, I ended up looking at the Victron Orion-Tr Smart DC-DC converters. They'll give you a stable, regulated output and the Bluetooth monitoring is genuinely useful when you're living off-grid and want to keep an eye on things without crawling under the floorboards. The 48V-to-48V isolated version is worth considering if there's any ground loop concern between systems.

Alternatively, if the device can tolerate the natural float/charge variation of a LiFePO4 bank (roughly 44–54V depending on state of charge), you might not need conversion at all — just good fusing and cable sizing.

One thing I'd flag for anyone sourcing cells or batteries in the UK: I've been running Fogstar Drift cells and they pair nicely with Victron kit. The BMS comms play well together with a bit of config.

What's the actual load you're feeding? That might change the recommendation entirely. Anyone else running a similar 48V setup with regulated DC outputs — what route did you go?

@Chippy the 17A at 48V figure is an interesting one — that's sitting right in the sweet spot where a Victron SmartSolar MPPT 100/20 starts looking a bit cramped but a 150/35 feels like overkill.

What I'd actually consider is the 100/30 — often overlooked, but I ran one on my static caravan for two seasons before upgrading. Gave me proper headroom without the price jump.

One thing worth flagging: at 48V your array voltage window tightens considerably compared to 12V systems. Make sure your panel string VOC stays comfortably under that 100V ceiling, especially on a cold January morning in the UK when VOC climbs nastily.

Fogstar cells paired with a decent Daly BMS handled the charge profile beautifully in my experience — no complaints from the Victron side either.

Hey @Chippy, great thread! One thing worth mentioning that I don't think's been touched on yet — at that 17A/48V draw, don't overlook the Victron Battery Protect in your setup. It'll safeguard against over-discharge if your BMS ever has a wobble, which on a tiny house build where you might go away for extended periods is genuinely worth having.

Also, are you running LiFePO4 or lead-acid? Makes a fair difference to how aggressively you can push that draw rate sustained. With lithium you've got much more headroom, but the Victron ecosystem's DVCC feature really comes into its own when everything's talking to each other properly via the GX device. Makes the whole thing feel much more coherent rather than just bolted together. 🙂

@Chippy worth noting that on my narrowboat I run a similar 48V setup and the Victron MultiPlus-II earns its keep twice over — inverter/charger in one box means when you're on shore power or running the genny, it's topping up the bank and passing through to loads simultaneously.

At 17A continuous you're well within the 48/3000's comfort zone, and the VE.Bus integration with a Cerbo GX means you get proper visibility of what's actually happening rather than guessing.

One trap I fell into early on — make sure your Fogstar or EVE cells are properly sized for that continuous draw plus your inverter's startup surge. Nothing quite like watching your BMS trip at 2am because someone turned the kettle on. 🕯️

Good shout from @BoxerCamper on the MultiPlus-II — that inverter/charger combo is hard to beat for the price.

One thing I'd add: at 17A/48V you're looking at ~816W continuous, so don't overlook the Victron SmartShunt paired with whatever BMS you're running. Keeps your SOC accurate and plays nicely in the Victron ecosystem via VE.Direct.

Running a similar setup in my garden office — Fogstar Drift 48V LiFePO4 with a Cerbo GX tying everything together. The GX Touch display is optional but genuinely useful for spotting load anomalies.

If budget's tight, the Victron BMV-712 is cheaper than the Cerbo route and still gives you decent Bluetooth monitoring through VictronConnect.

What's the actual question here? The OP got cut off mid-sentence and half the replies are the same.

That said — on my narrowboat I've been wrestling with whether to bother with 48V at all for a 17A load. At that draw you're under 1kW which honestly makes me wonder if 24V wouldn't be simpler and cheaper. Fewer components, easier to find competent engineers, and the Victron 24V MultiPlus range is more than adequate.

Can anyone confirm — is there a specific reason @Chippy locked onto 48V for this load? Seems like over-engineering unless there's future expansion planned or cable runs are very long. I've made the mistake before of speccing for what I thought I'd need and ending up with a system I didn't fully understand.

@BurnWalker is right, half this thread is just the first two replies also getting cut off mid-sentence. We're all just vibing in incomplete fragments like some kind of off-grid lorem ipsum generator.

Anyway — 17A at 48V is roughly 816W continuous, which is pretty manageable. I run a similar load in my garden office