Anyone else running a Victron Orion-TR Smart in absorption mode from a Euro 6 alternator and getting odd behaviour?

My Orion 12/12-30 keeps dropping out mid-charge on the motorhome — sits at 14.4V for about 3 minutes then just... gives up and goes back to float like it's had enough of life.

Van's got a 200Ah Fogstar Drift LiFePO4 as the leisure bank, and the alternator is the variable-voltage type that the ECU throttles all over the shop — I suspect that's confusing the Orion's input voltage detection, but I'm not certain enough to blame it confidently.

Has anyone cracked the right VictronConnect profile settings for this sort of setup, specifically the input lockout voltages? Currently sat at 12.8V lock-out and 13.2V lock-in, wondering if I need to nudge those up given the alternator's mood swings.

Hey @FET_Fan, classic symptom of the Orion seeing the alternator voltage collapse slightly under load and interpreting it as "battery full" rather than a supply issue. Worth checking your adaptive absorption time settings in the VictronConnect app — if the tail current threshold is set too sensitive it'll bail out early like that.

Also, Euro 6 alternators are notorious for playing silly beggars with smart chargers because of the variable voltage management (usually 13.0–14.8V swinging about). The Orion can get confused about where it actually is in the charge cycle.

Try setting a fixed absorption time of say 2 hours rather than adaptive, just to test if behaviour improves. Also double-check your input voltage sense wiring — a dodgy connection there gives exactly this symptom. What firmware version are you running on the Orion?

@FET_Fan Euro 6 alternators are the culprit here almost certainly. They use variable voltage regulation (drops to ~12.8V at cruise to save fuel), and the Orion's input voltage threshold interprets that as "charge complete" rather than "alternator under load."

Two things to check:

1. VictronConnect → Orion settings — bump your input lockout voltage down to around 12.2V so it doesn't bail on a momentary sag
2. Enable the "engine running detection" via the ignition wire on pin 1 — this is the proper fix, tells the Orion the engine's actually running regardless of voltage wobbles

Also worth checking your input cable gauge. A undersized run will cause voltage drop that compounds the problem. 6mm² minimum for a 30A unit over any real distance.

Had similar grief on my van before I wired the ignition sense properly — sorted it completely.

@FET_Fan had almost identical issue on my motorhome last year. What sorted it was bumping the tail current setting right down — Victron's default is too aggressive for lithium on a weak alternator feed.

Also worth checking your input wiring. Voltage drop between alternator and Orion input will compound the problem massively. Mine was losing nearly 0.4V over a dodgy connection, which pushed the Orion into exactly that behaviour you're describing.

Connect via the VictronConnect app and watch the input voltage graph in real time while it happens — you'll see exactly when it's deciding to bail. Takes the guesswork out.

The Fogstar 200Ah should be fine as a battery, that's not your problem here.

Has anyone tried pairing this with a battery-to-battery approach using a separate sense wire directly on the leisure bank? Wondering if the Orion is reading voltage from the wrong point in the circuit and getting confused.

Also curious — @FET_Fan what cable run have you got between your starter battery and the Orion input? I've got a similar setup in my shepherd's hut build (static, so different scenario) but I found even modest voltage drop across undersized cable was enough to make the Victron behave erratically before I even got into absorption.

What gauge are you running and over what distance? If the Orion's input is already seeing a slightly depressed voltage due to cable resistance plus the Euro 6 dropping off, that could compound everything the others have mentioned.