Swapped out my split charge relay for a Victron Orion-Tr Smart — worth the faff?

So I've been running a basic split charge relay in my Transit-based van for the past couple of years and it's always felt a bit agricultural. Charging was slow, I had no real idea what was going in or coming out, and I'm fairly sure it was hammering my leisure battery more than it should. Last weekend I finally bit the bullet and fitted a Victron Orion-Tr Smart 12/12-30A isolated DC-DC charger. Total cost with the cable, ANL fuse, and a bit of heat-shrink was about £210 all in.

The difference already feels noticeable. The Orion is pushing a proper 3-stage charge profile into my 100Ah lithium (a Fogstar Drift), and through the Victron Connect app I can actually see what's happening in real time. First run out after fitting it — about 90 minutes of motorway driving — took the battery from 48% up to 91%. That's a proper result compared to what the old relay was managing.

What I'm less sure about is whether I've set the absorption voltage correctly. I've got it at 14.2V which is what Fogstar recommend, but the Orion seems to be dropping out of absorption quite quickly — maybe 10 minutes — before floating. Is that normal for a lithium that's not deeply discharged, or have I got something configured wrong?

Has anyone else made this switch from a dumb relay to a DC-DC charger? Curious whether people think it's worth the extra cost, especially for those only doing occasional weekend trips rather than full-time living.

CopperDrifter | 847 posts

@GillWard Totally worth it in my opinion. The big thing people don't mention is how the Orion-Tr Smart handles the Euro 6 alternators properly — those smart alternators in modern Transits will throttle right back and barely charge your leisure battery through a basic relay. The Orion essentially tricks it into behaving itself.

The Bluetooth monitoring through the Victron Connect app is genuinely useful rather than just a gimmick — you can actually see charge current in real time rather than guessing.

One practical tip: make sure you're running adequate cable gauge to it. I initially underestimated the voltage drop on my install and wondered why it wasn't performing properly. Sorted it with proper 10mm² and it transformed the results.

What battery setup are you running on the leisure side? Makes a difference to how you configure the absorption settings.

ExpertCamper | 1,203 posts

@GillWard The thing that sold me on the Orion-Tr Smart was the isolated version — completely separates your leisure and starter batteries which is brilliant if you've got a lithium leisure bank. My Fogstar Drift 200Ah would've been a nightmare with a dumb relay because of the charging profile differences.

Also worth knowing: you can set it to only charge when the alternator is actually running properly (voltage threshold), so you're not accidentally dragging your starter battery down whilst sat on hookup.

The Victron Connect app integration is genuinely useful too — I can see exactly what my alternator's pushing into the bank in real time rather than just guessing.

Only downside? It will expose how underpowered your alternator is 😅

MasterProject | 203 posts

Slightly different use case here — I run a narrowboat rather than a van — but I made the same switch and the difference in charging efficiency alone justified the cost within a season.

One thing neither @CopperDrifter nor @ExpertCamper has mentioned: the engine-running detection via the alternator voltage threshold is genuinely clever. No more worrying about accidentally flattening your starter battery if you've left the Orion connected and the engine's off.

Worth checking which Orion variant suits your alternator though — some newer smart alternators with variable voltage outputs don't play nicely without adjusting the detection threshold in the VictronConnect app. Caught me out initially on the boat's Beta engine.

Is your Transit running a standard fixed-voltage alternator or one of the newer "smart" ones?

MoreTeaVicar | 312 posts

Different angle from me — I've got a static caravan rather than a van, but I fitted an Orion-Tr Smart to manage charging from a small generator into my leisure bank, and the Bluetooth monitoring alone changed everything.

Before, I was essentially guessing. Now I can watch exactly what's happening in real time via the VictronConnect app. When it started throttling back current on warm days, I knew about it rather than just wondering why my Fogstar batteries weren't hitting full charge.

The thing people underestimate is how much the absorption/float profile matters compared to a dumb relay just slamming voltage through. @GillWard your Transit alternator will thank you as well — proper current limiting means it's not being flogged constantly.

The setup faff is a Saturday afternoon at most. Then it just quietly gets on with it.

Thommo53 | 847 posts

@GillWard Short answer — yes, absolutely worth it. I made the same swap on my Sprinter about 18 months ago and the difference was night and day. The thing that really won me over was being able to set it up properly for lithium batteries, which my old relay obviously hadn't a clue about.

The Bluetooth monitoring through the VictronConnect app is genuinely useful rather than just a gimmick — I can see exactly what's happening whilst sat in a services car park wondering whether to bother plugging into shore power.

Installation took me an afternoon and the wiring diagrams in the manual are decent enough. Only gotcha I'd flag is make sure you've got adequate cable runs sorted beforehand — I had to redo mine because I'd been a bit optimistic about lengths. But overall, no regrets whatsoever.