Victron Orion 30A keeps cutting out on long motorway runs — anyone else had this?

Had this exact issue last summer on a long run down the M6. Turned out my Orion was mounted too close to the engine bay bulkhead and was thermal throttling after about 45 mins. Moved it to a spot with better airflow and haven't had a dropout since.

Few things worth checking:

• Ambient temp around the unit — these things are more sensitive to heat than Victron let on IMO
• Input voltage sag — if your alternator's struggling, the Orion will cut if input drops below threshold. Worth logging with a BMV or similar
• Firmware — had a mate whose unit was doing something similar, turned out to be an older firmware with dodgy behaviour on the engine detection algorithm

What's your install like? Enclosed box, open mount? And are you running the standard non-isolated or isolated version? I've got the isolated 12/12-30 in my Transit and it's been solid once the thermals were sorted, but I was pretty close to binning it before I figured that out.

Also curious whether it's cutting completely or just dipping output — Victron Connect should show you the history if you've got it paired. The charge history graphs are actually decent for diagnosing this sort of thing.

Others had similar? Feels like a fairly common one that doesn't get talked about enough on here.

@LuckySkipper classic thermal throttling story — I've seen this pattern loads of times on the narrowboat forums too, where people tuck the Orion into a poorly ventilated engine bay locker and then wonder why it sulks on long runs.

One thing worth checking that nobody mentions: the input voltage drop as your alternator warms up. On my setup I was losing nearly 0.8V at the Orion terminals after an hour of cruising, which was enough to trigger the low-voltage cutoff rather than thermal protection. Two completely different failure modes that look identical from the outside.

Stick a cheap Bluetooth voltage monitor on both input and output terminals before you assume it's heat. Saves a lot of head-scratching and unnecessary repositioning.

Good shout on the thermal throttling — I had something similar on my shepherd's hut build but caught it early because I'd mounted a small temperature sensor nearby.

One thing worth checking that nobody's mentioned: the input voltage threshold. On longer motorway runs your alternator voltage can actually drop slightly under heavy load, and if it dips below the Orion's minimum threshold it'll cut out entirely — looks identical to thermal throttling but it's a different problem.

Worth logging the input voltage over a full run with a Victron MPPT or even just a cheap Bluetooth shunt. Took me ages to work that out on mine.

Also — are you running the engine detection via the VE.Direct port or just voltage sensing? The latter can be a bit twitchy.

Mounted mine behind the bathroom panel on the narrowboat — never throttled once, though it does mean I get to crouch in an increasingly undignified position every time I need to check the bloody thing.

Similar story from me — I had my Orion 30A tucked behind the cab seat panel on a long transit van conversion. No issues in winter, but come July I noticed my Fogstar Drift 12V was barely seeing any charge after an hour on the A1.

Turned out it wasn't just location though. The wiring routing meant hot air from the engine blower was essentially bathing the unit continuously. Repositioned it low on the nearside wall, added a small 80mm fan salvaged from an old PC to encourage airflow across the fins, and she's been solid ever since.

Worth checking with VictronConnect whether you're actually seeing thermal throttle events logged — it'll show the charge current dropping in the history graph. That saved me about three hours of head-scratching before I found the actual culprit.