Victron MPPT Solar Chargers: Common Issues & Fixes

Victron MPPT solar chargers are known for their reliability, flexibility, and advanced performance in off-grid, RV, marine, and backup power systems. But even the best equipment can sometimes run into issues.

Whether your MPPT solar charger is not working, showing warning lights, or just behaving strangely, this guide will walk you through the most common problems and how to fix them.

The Charger is Unresponsive

If your charger appears completely inactive and the unit shows no LED lights, no Bluetooth detection, and no output, it likely means there is an issue with power input or internal protection.

• First, confirm that both solar panel voltage and battery voltage are present using a multimeter.

• Open the VictronConnect app to see if the charger is detected.

• If there is no response and voltages are in range, the charger may have gone into protection mode or may require a reset.

• Try disconnecting both battery and PV wires for a few minutes, then reconnecting.

Solar Input Voltage is Too Low

Victron MPPT chargers only begin charging when the solar panel voltage is at least 5 volts higher than the battery voltage. If your charger is in "Waiting for PV power" mode, low panel voltage is often the reason.

• Clean the solar panels and ensure there is no shading.

• Check all panel connections for corrosion or looseness.

• Verify that the total panel voltage is high enough to trigger charging, especially during early morning or cloudy conditions.

Battery is Not Charging Even When PV Is Active

The charger may be active, but the battery may not be receiving current. This issue can occur even when the system appears to be functioning.

• If the battery is already full, charging may temporarily stop; this is expected behavior.

• Confirm that battery cables are tight and the fuse is intact.

• In VictronConnect, review charge history and settings to make sure the battery type and voltage range are correct.

Overvoltage from Solar Panels

If your solar array provides more voltage than the charger can handle, it will shut down to protect itself.

• For example, a 150/35 MPPT can accept a maximum of 150 volts from solar panels. Exceeding this could cause permanent damage.

• If overvoltage is suspected, immediately disconnect the panels and test each string with a voltmeter.

• Reconfigure your array in series-parallel to lower the total voltage if needed.

Communication Problems

Many users experience difficulty connecting their Victron charger to the VictronConnect app.

• Make sure the Bluetooth light is flashing (on supported models).

• Restart your phone or tablet and make sure no other devices are currently paired.

• If using a VE.Direct cable, check the physical connections and try a different USB port or adapter.
  

Overheating or Overload Shutdown

Victron MPPT units are designed to protect themselves from excessive heat or current.

• Ensure the charger is installed in a well-ventilated space and not exposed to direct sunlight for long periods.

• Reduce system load or use appropriately sized cables to limit resistance and heat buildup.

• Review VictronConnect logs for error messages that indicate thermal shutdown or overcurrent protection.

Practical Troubleshooting Checklist

Use this quick reference list when diagnosing issues:

1. Confirm voltage at both battery and solar terminals.

2. Clean solar panels and inspect for shading.

3. Tighten and test all cables and connectors.

4. Check charge settings in VictronConnect.

5. Look for firmware updates inside the app.

6. Monitor charger temperature and environment.

When to Ask for Help

If you’ve tried these steps and still have issues, consider updating the charger firmware or resetting it to factory settings. If that doesn’t help, reach out to us.

Need to Upgrade Your Setup?

At Volts Energies, we offer a full range of Victron MPPT solar chargers. Whether you're upgrading your off-grid system or setting up solar for the first time, we can help you choose the right product and get it working properly.