Smart alternator won't charge with Orion DC/DC

Been scratching my head with this one on my Transit conversion build, so figured I'd post here before I pull everything apart again.

Running a Victron Orion-Tr Smart 12/12-30A (isolated) to charge my Fogstar Drift 200Ah lithium in the back. The Transit has a smart/variable voltage alternator — Ford's EEM system — which, as most of you probably know, doesn't hold a steady 14.4V. It pulses all over the place, sometimes dropping to 12.8V at idle or during regen braking events.

The Orion keeps going into fault or just refusing to kick into bulk charge properly. I've got it wired direct to the starter battery with appropriate cable sizing (6mm²), inline fuse, the works. Remote L-line connected to ignition feed.

A few things I'm considering:

• Whether the input voltage threshold needs tweaking in the Victron Connect app
• If I need a dedicated sense wire rather than relying on the L-line
• Whether a small buffer capacitor on the input side would help smooth the voltage enough to keep the Orion happy

Has anyone dealt specifically with Ford's smart alternator behaviour rather than the VAG systems that get most of the write-ups online? I know the Renogy DC-DC units supposedly handle variable voltage better out of the box, but I'd rather sort the Victron if possible given the rest of my system is already Victron kit.

What's your actual wiring setup if you've cracked this? Particularly interested in whether anyone's adjusted the 'input voltage lockout' threshold successfully.

@ExBrickie31 Classic smart alternator headache — the Orion's trying to sense voltage on the starter battery but the variable voltage from the ECU-controlled alternator keeps confusing it.

The fix that sorted mine on a similar Ford setup: enable the "ignition input" wire (pin L on the Orion). Wire it to a switched 12V ignition source rather than relying on voltage-sensing alone. This tells the Orion "engine is definitely running, crack on charging" regardless of what the alternator voltage is doing.

Also check your VictronConnect app settings — there's a "vehicle on" voltage threshold you can lower slightly. Fords often sit at 12.8-13.0V when the smart alternator backs off, which can fool the Orion into thinking the engine's stopped.

Don't forget the Orion needs a solid ground to chassis too, not just negative-to-battery.

@ExBrickie31 Ford's EEC (smart alternator) sees the Orion's input impedance as a load and promptly tells the alternator "job done, drop voltage" — classic ECU trolling. You need to wire the Orion's remote on/off pin to a ignition-live that only goes high once the engine is actually running (not just ACC), which breaks the feedback loop. Alternatively, some lads fit a small Victron Battery Sense on the starter side so the Orion gets a clean reference voltage reading. Worth double-checking you're on firmware 1.06+ too, as earlier builds had dodgy smart-alternator detection thresholds that'd make a grown man weep. My own Transit setup sorted itself entirely once I moved the remote trigger wire — three hours of head-scratching for a ten-minute fix.

Had this exact same nightmare on my Transit build last year. The fix that worked for me was using the engine running detection via the VE.Direct port rather than relying on input voltage sensing.

In the Victron Connect app, set the Orion to start on "alternator" mode and bump the start voltage threshold up to around 13.2V — the Ford smart alternator will still hit that briefly even when it's throttling back.

Also worth checking you've got a decent earth directly to the chassis near the alternator, not just piggy-backing off random bodywork bolts. Sorted about 80% of my issues tbh.

@OldSailor makes a fair point about the impedance thing too — that's why isolated variant is the right call here.

@WonkyMender which pin did you use for the engine running detection — did you tap into the ignition live or something from the fusebox? Wondering if there's a cleaner solution.

Also curious whether anyone's tried the Victron VE.Smart networking approach to work around this, where the Orion takes its charge decisions from the battery's BMS data rather than relying on alternator voltage sensing. Running a Fogstar Drift on my own setup and it does broadcast over Bluetooth — not sure if the Orion can actually act on that though.

The isolated version should theoretically handle the smart alternator better than the non-isolated, so slightly surprised it's still causing grief. What firmware version are you on @ExBrickie31? There were some updates a while back specifically around alternator detection thresholds.