Victron Orion 30A tripping out when engine revs drop at idle — normal?

Been having this exact issue with my Orion 30A in the van. Every time I pull up to a junction or hit slow traffic, the engine drops to idle and the Orion cuts out — then kicks back in with a clunk once revs pick back up.

From what I can tell, the unit is seeing the voltage drop below its threshold (think it's around 13.2V by default?) and interpreting that as the engine being off. Makes sense as a feature to protect the starter battery, but it's pretty annoying when you're doing stop-start town driving.

A few things I've tried or looked into:

• Adjusting the input voltage threshold via VictronConnect — you can lower it slightly, though obviously there's a trade-off with starter battery protection
• Checking alternator output — mine was only pushing about 13.4V at idle on a cold day, which is marginal
• Engine Shutdown Detection delay — there's a setting in VictronConnect that adds a delay before it cuts, which has helped a bit

Has anyone found a sweet spot with the threshold settings? And is this behaviour just par for the course with the Orion, or does it suggest my alternator isn't performing as well as it should at idle?

Also curious whether anyone's had luck using the remote on/off wired to an ignition signal rather than relying on voltage sensing — wondering if that bypasses this issue entirely or just creates different headaches.

TomJackson86 | 847 posts | ⚡ Solar & DC-DC enthusiast

@Nobby yeah this is totally normal behaviour mate, no need to worry. The Orion has a low voltage disconnect threshold — typically around 11.5-12.8V depending on your settings — and when you're idling, the alternator output can dip enough to trigger it, especially if you've got other loads pulling from the starter battery simultaneously.

Worth checking your "input lockout voltage" setting in VictronConnect if you haven't already. Bumping it down slightly (carefully, mind) can reduce the cycling. Also make sure your engine-to-charger cable run is properly sized — voltage drop on undersized cable will make the problem worse at lower RPM.

The clunk you're hearing is just the relay engaging/disengaging. Annoying but harmless. Once you're moving again and revs climb, alternator voltage recovers and it reconnects. 👍

KevClark | 312 posts | 🚐 Motorhome & Static Van

Had exactly this on mine. The Orion's got a low voltage cutout — engine at idle can dip below whatever threshold you've set, so it protects itself. Worth checking your input voltage settings in VictronConnect. You can nudge the "start voltage" down slightly, but don't go daft or you'll be pulling from a flat starter battery.

Also — is your alternator actually healthy? Mine was doing similar and turned out the alternator was marginal. New one sorted it dead quick.

⚠️ Don't confuse "normal behaviour" with "optimal behaviour" — there's a difference

OffGridHamish | 203 posts | 🏠 Tiny House & Shepherd's Hut

Mine did the same clunking dance at every roundabout until I bumped the low voltage cutout threshold down a notch in VictronConnect — turns out my ageing Land Rover's alternator has the voltage regulation of a tired pensioner at idle, so anything below factory default was enough to spook the Orion into a sulk.

BayJason | 1,204 posts | 🔌 EV Charging & Static Caravan

Worth noting the specific threshold here — the Orion-Tr Smart's default input voltage lockout is 13.2V (or 23V for 24V systems). Modern stop-start engines can dip well below that momentarily at idle, hence the cutout.

Two things to check in VictronConnect:

1. Input voltage lockout — you can lower this, but be cautious about pulling from a weak alternator
2. Delayed engine detection — if you're using that mode, tweak the voltage threshold to something more realistic for your specific vehicle at idle

@OffGridHamish the "clunk" is just the relay dropping in/out rapidly — not harmful but annoying.

I had similar behaviour on my static caravan's DC feed before I properly characterised what the supply voltage actually does under load. Five minutes with a multimeter logging idle voltage tells you exactly where to set the threshold.

CrafterDream | 847 posts | ☀️ Solar & Emergency Backup

The threshold @BayJason is likely referring to is 13.0V on the Victron Connect app — that's the default low-voltage disconnect. Modern Euro 6 engines commonly drop below this at idle, especially with stop-start disabled or during cold starts.

What fixed it on my setup: set the input voltage lockout to 12.6V and the restart voltage to 13.2V in VictronConnect. Gives the charger room to breathe without constant cycling.

Also worth checking your alternator voltage with a multimeter at idle — some Ford Transit bases barely manage 13.2V under load. If you're routinely sitting below 13.0V, no amount of threshold tweaking will fully solve it; you'd need to look at idle-up solutions or a dedicated alternator upgrade.

The "clunk" itself is just the relay engaging — perfectly normal mechanically.