Victron Orion 30A keeps dropping out on long motorway runs - anyone else?

Had the exact same saga last summer, towing the boat down to the south coast on the M3. Three separate dropouts over about 90 minutes, all happening once the engine was properly warm and we'd been cruising at 70mph for a while.

Turned out to be thermal shutdown. The Orion was tucked into a corner of my van conversion with basically zero airflow around it. Victron's own documentation is a bit coy about just how much heat these units throw off under sustained load, especially on a long run where your alternator voltage is rock solid and the unit's working hard the whole time.

My fix was a combination of things:

• Relocated the unit away from the corner into a spot with natural convection space above it
• Added a small 12V fan (triggered via a Victron temperature sensor) to move air across the heatsink
• Dropped the charge current to 25A rather than the full 30A

Honestly the current drop made the biggest difference. Slightly longer to charge the leisure bank (Fogstar Drift 100Ah LiFePO4) but zero dropouts since, even on a run up to the Lake District last month.

Worth checking your firmware is current too — there were some thermal management tweaks in earlier updates that made a noticeable difference.

Where exactly is yours mounted? And is it the isolated or non-isolated version? The isolated runs warmer in my experience, which might matter depending on your install.

Curious whether anyone's found a smarter solution than just backing off the current — feels like leaving performance on the table.

@VDH_Boats classic thermal throttling symptom — the Orion-Tr Smart 30A is notoriously fussy about airflow when mounted in an enclosed void.

Mine did identical on the M6 last August running the garden office battery bank. Fixed it by:

1. Relocating the unit away from the engine bay bulkhead
2. Adding a 12v brushless fan (Noctua NF-A4 — overkill but silent) tied to the ignition feed
3. Checking the input voltage settings in VictronConnect — the default "engine running" detection threshold sometimes mis-fires under load as alternator voltage fluctuates

Worth pulling the Orion's history in VictronConnect after a run — if you're seeing input undervoltage events rather than temperature shutdowns, the issue might actually be your alternator struggling under combined electrical load on a warm engine, which is a completely different fix.

What alternator rating does your tow vehicle have?

@VDH_Boats @PennineVanLifer had exactly this with mine mounted under the passenger seat — turned out it was basically sitting in a warm bath of recirculated air. Moved it to the cab bulkhead with a small 12v fan blowing across it and haven't had a dropout since.

Worth checking the VictronConnect app **

@VDH_Boats @CotswoldNomad oh this brings back memories — I had mine tucked into the bulkhead of the shepherd's hut tow vehicle last spring and honestly the dropout pattern was maddening. Took me ages to realise it wasn't thermal at all in my case, it was the alternator voltage drooping under sustained motorway load, and the Orion was interpreting that as "source too weak, abort mission."

Fitted a proper sense wire direct to the alternator output rather than relying on the battery terminal reading, and the dropouts just... stopped. Complete night and day difference.

Worth checking in the VictronConnect app — if your input voltage is hovering around 13.2-13.4V during the dropouts, that's almost certainly your culprit rather than heat. The threshold settings are adjustable but the sense wiring fix is more elegant really.

@VDH_Boats worth checking your VictronConnect history logs — the app timestamps every fault event and records the internal temp at dropout. That'll confirm whether it's genuinely thermal or something else entirely, like input undervoltage from a tired alternator struggling under tow load.

My garden office setup is static obviously, but I had a similar dropout pattern with a Victron unit that turned out to be marginal wiring — 6mm² cable looked fine visually but had a corroded ring terminal pushing resistance up just enough to trigger the protection circuit under sustained load. Volt-drop testing under actual load told the real story, not a static multimeter check.

If the logs show clean temps but voltage dips, I'd be pulling every connection between alternator and Orion and inspecting properly before assuming airflow is the culprit.