Orion XS reverse charging: charge a flat starter battery from your leisure battery

In short

The long awaited Orion XS reverse charging arrived in firmware v1.15. Victron calls it emergency reverse charge. It works on the Orion XS 12/12-50A, 12/12-70A and 1400. Tap the engine icon in the VictronConnect app (v6.43 or later). The Orion XS then uses your leisure battery to charge the starter battery for 15 minutes. It then pauses for 5 minutes so you can start the engine. So if you’re ever stuck at camp with a flat starter battery, an Orion XS on firmware v1.15 may get you going again without a jump starter or jump pack.

How does Orion XS reverse charging charge a starter battery from a leisure battery?

Normally the Victron Orion XS works as a DC DC battery charger. It charges the leisure battery from the starter battery and alternator, using its own charge algorithm. See our guide to battery to battery chargers for more information.

A reverse charge swaps the direction. VictronConnect then shows negative current on input and output. The best part is, an existing Orion XS install needs no extra wiring.

Treat it as a get you home feature, not a full jump starter. It puts some charge back into a starter battery. It can’t revive a worn out battery.

If you want it straight from the source, Victron’s own manual covers the Emergency reverse charge feature in full, including the exact safety notes for your model.

Which Orion XS models support reverse charging?

Model	Maximum reverse charge current	Starter battery charged to
Orion XS 12/12-50A	up to 25 A	14.4 V max
Orion XS 12/12-70A	up to 35 A	14.4 V max
Orion XS 1400	up to 25 A	14.4 V (12 V) or 28.8 V (24 V) max

All three need firmware v1.15 or later. Victron has released the feature for the Orion XS range only, so the Orion-Tr Smart doesn’t get it. Each model below is a Victron DC to DC charger with an ingress protection rating IP65 enclosure.

How do I update my Orion XS to firmware v1.15?

1. Update the VictronConnect app to v6.43 or later.
2. Connect to the Orion XS over Bluetooth and accept the update. Keep your phone close until the update finishes.
3. Check that Product info shows v1.15 or later.

Victron says you can also install v1.15 remotely from the VRM Portal. Your Orion XS must be connected to a GX device, such as a Cerbo GX or Ekrano GX, through its VE.Direct port.

Update at home while the starter battery is healthy.

On the Orion XS 1400, set Starter battery voltage (12 V or 24 V) in Product settings.

How do I start an Orion XS emergency reverse charge?

1. Switch the engine off. Check the Orion XS is in charger mode, as power supply mode doesn’t support it.
2. Connect in VictronConnect and tap the engine icon at the top left of the Status screen.

   

3. Check the target battery voltage and maximum current.

   

4. Tick I understand the feature and tap START. You can close the app during the countdown.

   

5. After 15 minutes the app shows Battery ready. Start the engine during the 5 minute settling window.

   

To stop early, tap the engine icon and confirm STOP. The Orion XS then returns to normal charging. You can start another run once the engine icon is live again. Victron doesn’t say whether repeat runs have a limit.

How much current does it deliver?

The Orion XS uses half its rated current, or your lowest current limit if that’s lower. It charges the starter battery to 14.4 V at most (28.8 V for a 24 V starter on the 1400).

It also protects the leisure battery. It holds the leisure battery voltage at 12 V (24 V on 24 V systems) and reduces current near that level. If the leisure battery sits at or below 12 V, no current flows.

By our calculation, that adds about 6 Ah at 25 A or 9 Ah at 35 A, before losses.

Is it safe for my batteries and wiring?

• Fuses and cables: reverse charging runs at half the rated current or less, so a correctly fused and sized install needs no changes. Follow the cable and fuse table in your model’s manual, with fuses at both battery ends.
• Chassis bond: a poor negative connection adds voltage drop and cuts current. Our guide to earthing and bonding your campervan’s electrical system shows how to get the chassis bond right.
• Lithium battery or lead acid: the 12 V floor protects either. Victron gives no lithium battery or BMS rules for reverse charging, so check your battery’s instructions. A battery monitor shows how much charge you can spare.
• Loads: Victron recommends switching off other loads, such as the fridge and inverter, during the run.
• Parallel units: start a reverse charge on every Orion XS, or switch the others off. A unit in normal mode would charge forwards against the one reversing.
• Remote off: a remote off doesn’t block reverse charging.

Why is my Orion XS reverse charge not working?

The engine icon is greyed out or missing. The button is only activated in charger mode once the Orion XS has stopped charging, through input voltage lock-out or engine shutdown detection. If the icon is missing, update the firmware and app.

Low or zero current. Victron lists long or thin cables, a weak or small starter battery, a starter battery that’s already fully charged, a nearly empty leisure battery, a second Orion XS charging forwards or a faulty battery. Measure both battery voltages at the Orion XS terminals.

The engine still won’t turn over. If the voltage collapses when you crank, the starter battery has probably reached the end of its life.

Need your Orion XS fitted or checked?

We’re an Authorised Victron Energy Installer. We fit, update and set up Orion XS chargers in our workshop at Witherslack. See our installs.

If your system is already connected to a GX, our remote monitoring and support can help too. Book your free 30-minute call with Tom. Preferably, before you’re stuck in the woods somewhere.

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