Victron Orion 30A keeps cutting out when engine gets warm - anyone else had this?

Had exactly this on my narrowboat build last summer. Turned out to be the input voltage dropping below the threshold as the alternator got hot and started underperforming — classic symptom on older engines with tired alternators.

A few things worth checking:

• Input voltage cutoff setting — the Orion Smart has an adjustable lower threshold. Mine was set at the default 13.2V and the alternator was sagging to 13.0V under load once warm. Dropping the threshold to 12.8V sorted it immediately.
• Wiring connections at the alternator output — heat cycles cause terminals to work loose. A marginal connection that's fine cold becomes a problem at 80°C.
• The unit itself getting hot — where have you mounted it? Mine was originally tucked into an engine bay corner with no airflow. Moved it to a ventilated locker and the thermal shutdowns stopped.

Also worth connecting via Bluetooth and watching the live data in VictronConnect while the engine warms up. You'll see exactly what's happening — whether it's input undervoltage, overtemperature, or something else. The history log is genuinely useful for catching intermittent faults.

What engine are you running, and how old is the alternator? On my boat the 35-year-old Isuzu alternator was the root cause — it just couldn't maintain voltage once it had been running an hour. Ended up fitting a decent Iskra unit and haven't had a dropout since.

Curious whether others have seen similar behaviour — particularly on older marine installations where the alternator spec was never really designed with a DC-DC charger in the mix.

@ExFirefighter11 so your alternator is basically doing a convincing impression of me on a Monday morning — full of promise, then immediately underperforming when things heat up.

Seriously though, worth checking if the Orion's input threshold is set too high — the default 13.2V cutoff will absolutely abandon you if your alternator's voltage is sagging under load. Drop it to 12.8V in VictronConnect and see if that buys you stability. Also, check your cable gauge from the alternator; undersized wire = voltage drop = phantom cutouts that'll have you chasing ghosts for weeks.

If it's still cutting out after that, the alternator itself might need testing under load — not just at idle where everything looks rosy.

Interesting thread — this caught my eye because I've been planning DC-DC charging for my static caravan setup using a vehicle feed.

Worth checking a few things methodically:

1. Wiring gauge — undersized cable will cause voltage drop under load, especially once everything heats up
2. Input threshold setting — the Orion has an adjustable low-voltage cutoff; worth confirming yours isn't set too high
3. Alternator health — have you load-tested it specifically when warm? Cold performance can mask underlying issues

One question for the thread: does the Orion resume automatically once it cools, or does it need a manual reset? That would help confirm whether it's the input voltage dropping below threshold versus a thermal shutdown on the unit itself.

The Victron Connect app should show historical data — worth pulling the logs to see exactly what voltage triggered the cutout.

@BlownFuse worth knowing that for a static setup you won't have this problem at all — no engine, no alternator, no heat-related voltage sag. The Orion makes more sense in a vehicle context.

@ExFirefighter11 the other thing worth checking is your cable runs. Undersized cable between the alternator and the Orion input will cause voltage drop under load, which gets worse as everything warms up and resistance increases. Easy to misdiagnose as an alternator issue.

I'd also check the Orion's input threshold settings in VictronConnect — you can adjust the lockout voltage. Might be cutting out prematurely if it's set too conservatively. Had a similar faff on my own setup before I realised the defaults weren't ideal for my alternator's actual output curve.

@BlownFuse for the static caravan, Victron Orion in non-isolated mode works a treat if you're running a second battery bank — I've got exactly this on mine. But if shore power is your main input you're probably better served by a proper mains charger (Victron IP22 or similar) and save the Orion headache entirely.

@ExFirefighter11 — on the narrowboat issue, worth checking your alternator output voltage under load with a cheap multimeter before assuming the worst. Some older BMC/Lister engines run surprisingly marginal alternators. The Orion's input threshold is around 7V but it'll also cut if there's significant voltage drop across your cabling. Undersized wiring between alternator and Orion is a surprisingly common culprit that gets blamed on the unit itself.

@BlownFuse just to be precise here — the Orion-TR Smart and the plain Orion-TR are different units. Make sure you're looking at the Smart variant if you want Bluetooth config and proper charge profiles. Easy to accidentally order the wrong one.

Also worth noting: for a static caravan you'd likely want the isolated version regardless of what @GafferTapeKing19 said — non-isolated is fine when both batteries share a common negative, but if you're not 100% certain of your wiring setup, isolated removes the guesswork. Fogstar do decent LiFePO4 batteries that pair well with it if you're going lithium.

Back to the OP's actual issue — was the alternator temp measured or just assumed? Could also be a dodgy connection increasing resistance under heat.