Troubleshooting Guide: Orion DC-DC Charger Not Charging Consistently

⚠️ Important: A relay must be installed in your Orion DC-DC charger setup.
 This relay should only allow the charger to operate when the engine is running, preventing it from draining your starter battery when the engine is off.

? The Root of the Issue: Alternator Behaviour

Most Orion charging problems come from variations in how different vehicle alternators behave — especially with newer “smart” alternators.

Some alternators output as low as 10.5V to 11V, even when the engine is running. If your Input voltage lock-in is set higher than this (e.g. 12V), the Orion will stop charging because it assumes the engine is off.

This can be frustrating — but it’s easily fixable with a few setting adjustments.

✅ The Fix: Tune the Input Voltage Lock Settings

To keep your charger working reliably, you’ll need to adjust the voltage thresholds in the VictronConnect app.

Step-by-step:

1. Start with recommended values:
   
   

   • Input voltage lock-in: 12.5V
     
     

   • Input voltage lock-out: 11.5V
     
     

2. If charging keeps dropping out while the engine is running:
   
   

   • Gradually lower the Input voltage lock-in (try 12.0V → 11.5V → 11.0V).
     
     

   • Adjust the lock-out slightly lower (e.g. 10.5V) to maintain proper hysteresis.
     
     

3. Why the relay is essential:
    If the lock-in voltage is low, the Orion could turn on even when the engine is off — for example, if battery voltage is high due to solar or other sources.
    Installing a relay that only activates with the engine ensures the charger only operates when it should, protecting your starter battery.
   
   

? Why Is My Alternator Only Putting Out 10.5V?

In modern vehicles, this is surprisingly normal:

• Smart alternators (common in Euro 5/6 vehicles) reduce output voltage at times to improve fuel economy.
  
  

• Alternator output can vary based on load, engine RPM, and battery state of charge.
  
  

• In some vehicles, the alternator isn’t directly connected to the starter battery. It may charge through a battery management module, sensor, or intelligent fuse system, reducing the voltage seen at the Orion’s input.
  
  

? How to Diagnose the Problem

To find out what’s really going on:

1. Measure voltage at the Orion’s input terminals while the engine is running.
   
   

2. Compare it to the starter battery voltage.
    A large difference indicates voltage drop or indirect alternator wiring.
   
   

3. Check your cabling and grounding:
   
   

   • Use thick, properly sized cables.
     
     

   • Keep wiring as short as possible.
     
     

   • Double-check all grounds and crimps.
     
     

4. Ensure the relay is correctly wired to a true engine-on signal — such as ignition, D+ (if available), or ECU-controlled output.
   
   

⚠️ Why the Relay is Critical

Lowering the Input voltage lock-in helps keep the Orion charging in vehicles with low alternator output — but it also increases the risk of the charger activating when it shouldn’t (e.g. engine off, solar active).

The relay solves this:

• It ensures charging only happens when the engine is on.
  
  

• It avoids unnecessary discharging of the starter battery.
  
  

• It makes your system far more predictable and reliable.
  
  

Need Help?

If you’re still having trouble, send us:

• Your vehicle make, model, and year
  
  

• Orion settings (lock-in / lock-out values)
  
  

• Whether a relay is installed
  
  

• Voltage readings at the Orion and starter battery
  
  

We’re happy to help you fine-tune your setup for reliable and safe charging.