Orion XS does not charge the house battery

A working Orion XS lights or flashes its LEDs and connects to VictronConnect. If all LEDs are off, measure the voltage directly at the charger battery terminals with a multimeter (input and output). Measuring at the terminals rules out problems with cables, fuses and switches in between.

The manual warns: the red or “+” marked cable does not necessarily have to be positive — a wiring mistake may have been made during installation. Reverse polarity is often accompanied by a blown fuse in the battery cable. Orion XS is not protected against battery reverse polarity, and such damage is not covered by warranty.

To operate, the remote terminal needs a bridge link (a wire loop) — or external control (switch, relay, BMS). It switches on when:

• L and H terminals are shorted by a switch or relay contact,
• L terminal is connected to battery negative (the “on” level below 6 V),
• H terminal is at a high state (the “on” level above 4 V).

Check that the connector is fully inserted and that the bridge link makes contact. If the lithium battery BMS controls the remote terminal, charging may have been switched off by the BMS; see BMS has cut charging off.

In charger mode, Orion XS detects whether the engine is running by measuring input voltage (engine shutdown detection, enabled by default). Factory values for the default “Smart alternator” setting:

Between the shut-off threshold and the start threshold, the charger reduces current so that the voltage at its input does not fall below the shut-off threshold. That is why at low engine speed and with a weak alternator, current may be noticeably lower than nominal.

Voltage drop on the input cable lowers the voltage the charger “sees”. Example from the manual: 5 m of 16 mm² cable both ways (approx. 11 mΩ) at 50 A gives a drop of about 0.55 V — the lockout threshold should then be no higher than 13.1 V − 0.55 V = 12.55 V. Cable that is too thin, poor terminals or loose connections can therefore stop charging while driving.

By default, Orion XS treats the engine as off when input voltage falls below 13.1 V for more than 1 minute. In Euro 6 vehicles, the alternator may be switched off while driving and the house battery may then not charge properly. The voltage then drops to the battery’s resting voltage (about 12.6 V), and Orion XS assumes the engine is off. The manual states that even within one make and model, charging strategies can differ (for example, in VW T6s detection works for some users, but not for others).

With a sufficiently large electrical load, the alternator operates at a voltage of at least about 13.8 V and detection works. If not, the manufacturer recommends disabling engine running detection in VictronConnect and enabling charging with an external signal via remote. Options according to the manual:

• Engine running signal from the vehicle — the most reliable, but it can be difficult to access and may require activation in the vehicle software.
• Vibration sensor — external vibrations (ferry or train transport, loud music) may be mistaken for engine running; power it from the ignition switch so charging requires both conditions.
• D+ — often unavailable in Euro 6 vehicles; D+ simulators usually work in a similar way to built-in detection, so if that fails, they probably will not help either.
• Ignition switch — the manufacturer does not recommend this: with the ignition on and the engine off, Orion XS discharges the starter battery.

You can also bypass detection with a voltage above 8 V on terminal L — then the charger is on regardless of detection, but this does not bypass remote on/off; remote must still be configured and enabled correctly. More: Orion XS datasheet.

• Load on the DC side too high — Orion XS also powers loads (fridge, lights, inverter); the battery charges only with the surplus.
• Battery almost full — current decreases during the absorption phase (about 80–100% SoC) and is very low in float. This is not a fault.
• Charging voltages too low — check absorption and float according to the battery manufacturer’s recommendations.
• Voltage drop on the output cables — at full current (bulk), compare the voltage at the Orion terminals with the voltage at the battery terminals.
• Temperature difference — Orion XS assumes the battery is at the same temperature as it is, and corrects the voltage. With lithium batteries, temperature compensation is usually disabled (for lead-acid batteries the default is −16.2 mV/°C).
• Input or output current limit too low in VictronConnect.
• Not enough power from the alternator — at low engine speed, alternator power may drop to about 50%; an overheated alternator also limits output. The history in VictronConnect (40 cycles) will show whether the charger reaches float at all.
• Orion overheating — full power up to 40 °C ambient temperature with vertical mounting, terminals facing down and space for ventilation; in a closed locker, provide cool air in and hot air out.