Anyone else running a Victron Orion-Tr Smart alongside solar? Curious how you're handling charge priority

So I've got a 40A Orion-Tr Smart (non-isolated) pulling from my van's alternator into a 200Ah lithium leisure battery, and it's been brilliant for the most part. The issue I'm running into is when I've also got a 200W roof panel feeding a SmartSolar 100/20 MPPT at the same time — both chargers are trying to top the battery up simultaneously and I'm not entirely sure how well they're playing together.

I've got everything linked up via Bluetooth and they're both on the same VE.Smart network, so in theory they should be sharing battery voltage and temperature sense data. But I've noticed on sunny days when the solar is already pushing the battery into absorption, the Orion doesn't seem to back off at all — it just carries on at full chat regardless. I'd have thought it would at least throttle down a bit.

Has anyone actually figured out a clean way to prioritise solar over the alternator input, or are most people just letting both run and accepting the slight overlap? I'm a bit wary of stressing the alternator unnecessarily when the sun's doing most of the heavy lifting anyway. Running a 2019 Transit if that makes any difference.

@EdCampbell80 Running almost the same setup in my motorhome — Orion-Tr Smart 30A non-isolated feeding a pair of Fogstar Drift 100Ah batteries, with a 200W Renogy panel through a Victron SmartSolar MPPT.

The thing that sorted it for me was creating a shared VE.Smart network between the Orion and the MPPT. Once they're both talking via Bluetooth, the Orion can see the battery's actual state of charge and backs off accordingly rather than both sources hammering in simultaneously.

Key thing — set your absorption voltage identical on both devices, otherwise whichever is set higher effectively overrides the other and you lose the coordination entirely.

Took me an embarrassingly long afternoon to figure that out on a trip to the Lakes last autumn. What does your solar setup look like — are you running a Victron MPPT or something else?

Got this exact combo running on the narrowboat — Orion-Tr Smart 30A feeding 200Ah Fogstar Drift via MPPT solar (Victron SmartSolar 100/30).

The key thing I found: set your Orion absorption voltage slightly lower than your MPPT. That way solar naturally takes priority when it's generating well, and the Orion fills the gaps underway without fighting the MPPT for control.

Also worth enabling the BMS port integration if you're using a smart BMS — the Orion will back off when the battery signals it's happy, regardless of what the alternator's doing.

One thing @DontPanic25 probably knows already — in the VictronConnect app, check your engine shutdown detection threshold. Default caught me out once; tweak it to suit your specific alternator's behaviour or you'll get false cut-offs.

Worth noting that in VictronConnect you can set the Orion to only activate above a certain input voltage threshold — I've got mine set to 13.2V so it won't kick in until the alternator is properly spinning rather than just draining the starter battery at idle.

For the cabin setup I also have it wired through a BMS-controlled relay, so if the lithium hits absorption the BMS can signal the Orion to back off independently of whatever the MPPT is doing. Keeps everything from fighting each other.

@MrBodge65 good shout on the MPPT coordination — the shared voltage bus approach is underrated. Most people overthink the priority logic when really the batteries just sort it out naturally if your absorption/float thresholds are consistent across both chargers.

Great thread — I've been running this exact combination for about eight months now and the piece that made everything click for me was enabling the engine detect function via VictronConnect and setting my input voltage threshold to 13.2V. Means the Orion won't even think about starting until the alternator is properly spinning.

One thing nobody's mentioned yet — if you've got a Cerbo GX or Venus device in the mix, you can get the Orion and your MPPT talking properly through VE.Smart Networking, so they're sharing battery voltage and temperature data across the network rather than each device making decisions in isolation. Makes the overall charge profile noticeably smoother in my experience.

@MrBodge65 curious whether you're seeing any issues on the narrowboat when the engine's at tickover for long periods — I noticed my alternator voltage drooping occasionally under those conditions.

Good timing on this thread — I've got the same Orion-Tr Smart (30A isolated version) running into a 200Ah Fogstar Drift on my static caravan, paired with a Victron SmartSolar MPPT.

One thing nobody's mentioned yet: if you're on VE.Smart Networking, the Orion can actually see the battery voltage being reported by the MPPT rather than relying on its own sense wire. Made a noticeable difference to how accurately mine decides when to back off. Worth enabling if you haven't already.

Also worth checking your absorption voltage settings match between the two chargers — I had mine slightly mismatched initially and it was causing the Orion to keep pushing when the MPPT had already signalled the battery was satisfied. Small thing but caused confusion for weeks.