Victron Orion-Tr Smart 3x30A – Low input voltage at full output and engine shutdown detection issues

Been running a similar setup on my boat — two Orion-Tr Smart 30A units in parallel feeding a 200Ah Fogstar Drift LiFePO4. Recognised this immediately.

The low input voltage thing is a genuine headache. Under full load both units pull hard from the alternator and the starter battery voltage sags noticeably. Victron's default low voltage cutoff then starts getting nervy and you can see the units throttling back in the app. Ended up tweaking the input lockout threshold down a touch which helped, but felt a bit like a bodge.

The engine shutdown detection is the other pain. I've got mine set to alternator sensing mode rather than a dedicated wire from ignition, and it occasionally decides the engine's off when it isn't — usually at low revs on tickover in the marina. Comes back fine but it's annoying and I don't fully trust it.

A few things I've tried:

• Heavier cable runs direct to alternator output (made a real difference)
• Adjusting the absorption voltage to suit the Fogstar BMS specs
• Turning off the pre-alarm in VictronConnect to reduce the noise

Curious whether anyone's run three units simultaneously — presumably the voltage sag gets worse? Also wondering if the VE.Smart networking between units actually helps smooth things out or just adds complexity.

Anyone else on a boat or shepherd's hut setup dealing with this? Feels like a thread worth digging into properly.

@StevePrice89 mate the Victron just sees that voltage drop and thinks "nope, not today" 😂

Genuine question though — have you checked what your input voltage threshold is set to in the VictronConnect app? Mine kept shutting down on the motorhome until I realised I'd basically set it so sensitive it was detecting *me

WonkyWarden | Posts: 847 | Location: South Wales

@StevePrice89 worth checking your alternator output voltage under load — some older marine alternators barely crack 13.8V when they're working hard, which leaves the Orion precious little headroom to do anything useful. The 30A units need roughly 1.2V differential minimum to operate properly.

On the engine shutdown detection side, have you adjusted the input voltage lockout threshold in VictronConnect? Default settings can be a bit aggressive. I'd also look at adding a small capacitor or a dedicated sense wire directly at the alternator output rather than relying on the battery voltage reading — reduces false shutdowns considerably on boats where cable runs are longer than ideal.

What's your alternator rated at? That'd help narrow things down. Three 30A units from a modest alternator could genuinely be asking too much of it.

@StevePrice89 running three of the 30A units in parallel on my narrowboat and the engine shutdown detection is basically useless unless you've got your input thresholds dialled in properly via the VictronConnect app — mine was cutting out twenty minutes after I'd already moored up and put the kettle on.

@EssexNomad three units in parallel sounds like my kind of chaos — my van's got two Orions and the engine shutdown detection is so jumpy it practically detects me thinking about turning the key 😅 Bumped the engine detection: alternator voltage threshold down in VictronConnect and it's been miles better — worth a poke around in there before you start blaming the wiring like I did for an embarrassing three weeks.