Victron Orion 30A keeps cutting out when engine revs drop at idle

Had almost the exact same drama on my narrowboat last spring. The Orion kept dropping out every time we were ticking over waiting for a lock — maddening when you're trying to keep the leisure bank topped up on a long cruise.

Turned out my issue was the input voltage threshold set too conservatively in VictronConnect. The Orion is remarkably sensitive to voltage dips at idle — engine alternator output can wobble quite a bit when revs drop, and if your threshold is sitting at say 13.2V, even a brief dip below that will trigger a shutdown.

A few things worth checking:

• Lower the input voltage threshold slightly in VictronConnect — I dropped mine to 12.8V and the dropout problem largely vanished
• Check your cable runs and connections between alternator and Orion — voltage drop on a marginal cable will compound the idle problem considerably
• Make sure your engine battery is in decent nick — a weak starter battery can cause all sorts of phantom voltage behaviour under varying load

Worth noting the Orion also has a restart delay setting — if yours is quite long, it might seem like it's cutting out repeatedly when actually it's just slow to recover after a single event.

I'm running a 30A unit feeding a pair of Fogstar 100Ah lithiums in the back cabin, and once I'd sorted the threshold settings it's been rock solid even on tickover.

What alternator are you running? And have you got any other significant DC loads active when it cuts out — fridge, inverter, that sort of thing? That might point us somewhere useful.

@DorsetCamper classic low-voltage dropout at idle. Worth checking your input voltage threshold in VictronConnect — default is 13.2V but alternators on tickover can dip below that easily, especially on older engines.

A few things I'd try:

• Lower the input lockout to 12.8V (carefully, don't go too far)
• Check your engine battery wire gauge — undersized cable causes voltage drop under load
• Enable the "ignore input voltage" timer if your firmware has it — gives it a few seconds to recover before cutting

On my cabin setup I had similar grief with a Renogy unit before switching to the Orion. The Victron is far more configurable once you're in the app properly.

Idle voltage really is the culprit 9 times out of 10 with this symptom.

@DorsetCamper nothing quite like the sound of your Orion clicking off right as the lockkeeper gives you the death stare for holding up the queue 😅

Beyond what @EmmaEdwards82 said about the threshold, also check your input cable sizing. I had this exact issue on my narrowboat setup — turned out my 6mm²

@DorsetCamper ooh this rings a bell — had something similar with my static van setup, though obviously not at locks!

Quick question though — are you running the Orion isolated or non-isolated? I've got the isolated version on mine and I wondered whether the engine battery and leisure bank sharing a common negative could affect the dropout behaviour differently?

Also, what's your alternator rated at? I've heard some of the older narrowboat engines have quite weedy alternators that really struggle to maintain voltage under load at idle. Would the Orion even see a stable enough input to stay happy?

@EmmaEdwards82 makes a good point about the input threshold — what's yours currently set to? Factory default on mine was something like 11.5V but I nudged it down slightly. Probably not advisable but curious what others have done?

@EmmaEdwards82 makes a fair point about the input threshold, but I'd want to clarify exactly which setting you're adjusting — there's a distinction between the input voltage lockout and the input voltage restart threshold in VictronConnect that trips people up. If the restart voltage is set too close to the lockout voltage, you'll get rapid cycling rather than a clean cutout.

On my van build I found idle voltage on the alternator was genuinely only sitting around 13.2V on a cold engine — is anyone actually measuring the starter battery terminal voltage at the Orion's input terminals under load, rather than just at the battery posts? Voltage drop across cabling could be pushing you below the lockout threshold even when the alternator itself is producing adequate output. What cable gauge and run length are you working with?

Exactly the scenario I've been worried about with my motorhome setup. When the engine's at idle, is the alternator voltage actually dropping below the Orion's default input threshold, or is it more of a transient spike that's triggering the undervoltage protection?

Worth checking with a multimeter directly at the Orion's input terminals while idling — not just at the battery. I've read that voltage drop across the wiring can be significant enough to cause nuisance cutouts even when the alternator should be putting out enough.

@FormerMariner1 — curious what setting you're referring to specifically. In the Victron Connect app there's both an input undervoltage shutdown and a restart threshold. Are you adjusting one or both? Getting those two values dialled in correctly seems to be where people go wrong.