Victron Orion-Tr Smart 30A — is the non-isolated version actually fine for a van build?

So I've been down a rabbit hole for about three days now trying to sort the DC-DC charging side of my Transit conversion. I had a Renogy DC-DC unit on the boat and it was fine, but everyone on the van forums seems to worship at the altar of Victron, so I picked up an Orion-Tr Smart 30A second-hand. Only afterwards did I notice it's the non-isolated version, and now I'm seeing horror stories about earth loops and fried alternators.

My setup: 200Ah Fogstar Drift LiFePO4 in the back, stock Ford alternator (140A I think), chassis earth shared throughout as normal. No solar yet — this DC-DC is the main charging source for now. The Orion is going between the starter battery and the leisure bank, roughly 2.5 metres of cable run.

From what I can gather, non-isolated is technically fine when both batteries share a common chassis earth — which they do in a standard van build. The isolated version is more for boats or situations where you've got truly separate earth systems. But I keep reading contradictory stuff and I'm going cross-eyed.

Has anyone actually run the non-isolated Orion long-term in a similar Transit/van setup without grief? Did you do anything special with earthing, or just bolt it in and crack on?

@JohnDixon the isolated vs non-isolated question tripped me up on my static caravan setup too. Short answer: non-isolated is generally fine if both batteries share the same chassis ground — which in most Transit builds they will. Where it gets complicated is if you've got a split-charge relay already in the mix or your leisure battery negative isn't bonded to the chassis in the same place as the starter battery.

On a boat you'd want isolated every time (different earthing conventions), but a standard van conversion? Non-isolated Orion-Tr Smart 30A is what most people fit and it does the job well.

Main thing I'd check — is your Transit a newer CAN-bus managed alternator? Because that changes things around input voltage thresholds regardless of isolation type.

Non-isolated is absolutely fine in a Transit as long as your leisure and starter batteries share a common negative — which they do, because Ford didn't design it with your overthinking in mind. 🚐

The Victron Orion-Tr Smart 30A non-isolated is what I've got in my van and it's been faultless; the engine-running detection via the input voltage threshold means it won't flatten your starter either. Only reason to go isolated is if you've got a completely separate chassis ground situation — think certain boat setups or some motorhome habitation areas where things get weird.

Save the £40-odd quid difference and spend it on a Fogstar Drift cell or two instead. That's where it actually matters.

Just to add a practical point that @Chalky and @HMK_Sparks haven't touched on yet — the non-isolated Orion-Tr Smart is actually the one I'd recommend for a Transit build specifically because the shared chassis ground means you avoid any potential ground loop issues you can sometimes get with isolated units wired carelessly. I've had mine running in a Sprinter for about 18 months without a hiccup. The Bluetooth app is genuinely useful for tweaking the charge profile too, especially if you're running lithium. Only caveat: make sure your cable runs are properly sized and fused at both ends — the 30A unit will happily pull significant current and Victron's own wiring guidelines are worth following to the letter.

Following on from what @Paul1999 was getting at — can anyone confirm whether the non-isolated version handles the engine-off scenario properly? My concern with my motorhome setup is that when I'm on hookup and the alternator isn't running, I don't want any weird backfeed through the Orion into the starter circuit. Is the Smart variant intelligent enough to prevent that, or do you need to wire the ignition sense wire regardless? I've got a Victron SmartSolar already talking to my MPPT via Bluetooth and ideally want everything networked through VE.Smart — does the non-isolated Orion actually join that network properly or is that only the isolated version?

Has anyone actually used the non-isolated version in a setup where they're also running a Victron SmartShunt on the leisure side?

Wondering whether the shared negative causes any measurement headaches — I've got a shunt on my shepherd's hut build (isolated setup there so no issue) but planning something similar for a motorhome conversion and want to get the wiring right first time.

Specifically: does the shunt need to sit between the negative busbar and the leisure battery with all negatives from the van body routed correctly, or does the shared negative in a non-isolated setup complicate that?

@Paul1999 curious what point you were about to make too — looks like your post got cut off.

To answer @PikeTom's question directly — yes, I ran exactly that combo in my Sprinter for about 14 months. Non-isolated Orion-Tr Smart 30A feeding into a 200Ah LiFePO4 bank with a SmartShunt on the negative. No issues whatsoever with the SmartShunt readings getting confused or any ground loop nonsense. The two talk nicely together over VE.Smart networking via Bluetooth, which means the Orion actually sees the battery voltage at the battery rather than relying on its own sense wire. Makes a noticeable difference to charge accuracy. Only caveat I'd add is make sure your chassis ground connections are genuinely clean and tight — the non-isolated version will absolutely highlight any dodgy earths you've got lurking. Sort those first and you'll have no bother.