How to Configure Victron MPPT Charge Controller Settings

Key Takeaways

• VictronConnect is the recommended software for configuring Victron MPPT charge controllers and for automatic firmware updates.
• Manual configuration using the mpptprefs.exe tool requires a VE.Direct to USB cable and a Windows PC.
• For 36V battery systems, the battery voltage must always be set manually, as auto-detection is not supported.
• Always disable temperature compensation (set to 0) when using Lithium batteries to prevent incorrect voltage adjustments.

How do I configure my Victron MPPT charge controller settings?

You can configure your Victron MPPT charge controller settings using either the recommended VictronConnect software or the mpptprefs.exe tool. While VictronConnect is preferred for its user-friendliness and automatic firmware updates, the mpptprefs.exe tool provides direct access to various parameters for manual adjustment.

Preparing Your Victron MPPT for Configuration

Before adjusting any settings, ensure your Victron MPPT charge controller is properly connected and powered. The specific steps depend on your chosen configuration method and MPPT model.

Diagnosis Steps

1. Identify your MPPT model: Note the specific model number of your BlueSolar MPPT charge controller (e.g., MPPT 75/15, MPPT 150/35). This helps determine compatible voltage settings and powering options.
2. Choose your configuration tool:

• • VictronConnect (Recommended): This tool is recommended for its comprehensive features and automatic firmware updates. Consult the Victron Energy website for specific VictronConnect instructions, as this document focuses on mpptprefs.
  • mpptprefs.exe (Manual Tool): If using mpptprefs.exe, proceed with the following steps.

3. Connect the MPPT to a PC (for mpptprefs.exe):

• • Connect a VE.Direct to USB cable to your BlueSolar MPPT Charge Controller.
  • Connect the other end of the cable to a Windows PC.
  • If the cable is not recognized, you may need to download the driver from the VE Power Setup section on the Victron Energy software page.

4. Power the charge controller:

• • For models like the MPPT 70/15, 75/10, 75/15, and 100/15, the controller can be powered from either the battery terminals or the solar panel terminals.
  • Other models can only be powered from the solar panel terminals.

5. Start mpptprefs.exe: Double-click the mpptprefs.exe tool to launch it on your Windows PC.

Understanding Victron MPPT Charge Controller Settings

The mpptprefs.exe tool allows you to modify various operational parameters of your Victron MPPT charge controller. These settings are crucial for optimizing battery charging and system performance.

Detailed Configuration Options

This section details the specific settings available through the mpptprefs.exe tool for Victron BlueSolar MPPT charge controllers. Remember that VictronConnect is the recommended tool for configuration and firmware updates.

Battery Voltage Configuration

The battery voltage setting determines the nominal system voltage. You can set it to auto-detection (0) or a fixed voltage.

• Auto-detection (0): "Set the battery voltage to auto detection (0)".
• Fixed Voltage: You can select "a fixed voltage (12, 24, 36, 48) to disable the auto detection."
• 36V Systems: "36 volts cannot be detected automatically. For systems that require this voltage, it must always be set manually."
• Model Compatibility: "36 and 48 volts are only available on models that support these voltages, such as the MPPT 150/35."
• Cyrix-Li-charge Relay: "Always fix the battery voltage when connecting the MPPT behind a Cyrix-Li-charge relay."

Charge Voltage Settings

These settings define the critical voltage points for your battery's charging cycle.

• Absorption voltage: This setting is modifiable ("a - Modify absorption voltage").
• Float voltage: This setting is also modifiable ("f - Modify float voltage").

Current Limit

You can adjust the maximum current the MPPT will supply.

• Modify current limit: This setting is modifiable ("c - Modify current limit"). It "Allows you to set a lower maximum charge current."

Equalization Settings

Equalization is a controlled overcharge to balance battery cells, primarily for flooded lead-acid batteries.

• Equalisation voltage: This setting is modifiable ("i - Modify equalisation voltage"). It is "Available from firmware 1.16 and higher."
• Auto equalise mode: This feature allows you to schedule automatic equalization. It is "Available from firmware 1.16 and higher." Requires adequate ventilation.
• • "0 = off"
  • "1 = daily"
  • "2 = every other day"
  • "... (up to) 250 = every 250 days"

Temperature Compensation

Temperature compensation adjusts charging voltages based on ambient temperature, which is crucial for lead-acid batteries.

• Set-up temperature compensation: The "Allowed range -21mV/K .. 21mV/K".
• Lithium Batteries: "use value 0 to disable the temperature compensation (e.g. for Lithium batteries)." For more information on battery types, refer to our guide on understanding battery types for solar.

Absorption Time Limit

This setting controls how long the MPPT stays in the absorption phase.

• Set-up the absorption time limit: "Enter the time value in the notation hh:mm, where hh=hours (0..12), mm=minutes (00..59)."

Load Operation Mode

For MPPT models with a load output (e.g., MPPT 70/15, MPPT 75/10, MPPT 75/15, and MPPT 100/15), this setting controls how the load output operates.

• Modify load operation mode: This setting is modifiable ("m - Modify load operation mode").
• Default: "By default the battery life algorithm will be used (option 1)."
• Communication: "if you require communication with the charger (e.g. when connecting a Color Control) you can use options 2 or 3 to preset a conventional algorithm."
• Custom Algorithms: "Options 5 and 6 can be used to create custom algorithms, with programmable switch on and switch off levels."
• Always Off/On: "modes 0 (always off)" and "4 (always on)".

Factory Defined Battery Table

You can revert to the manufacturer's default settings.

• Switch back to the factory defined battery table / rotary switch position: This option is available ("t - Switch back to the factory defined battery table / rotary switch position").

Lighting Controller Functionality

Some MPPT models support lighting control.

• Availability: "The lighting controller (timer) functionality is available from firmware version 1.15 and higher."
• MPPT 70/15 Specific: "An MPPT 70/15 needs to be from year/week 1308 or later." You can check the serial number format "HQYYWW..." where "HQ1309DER4F means 2013, week 09."

Saving Settings

After making adjustments in mpptprefs.exe, ensure you save them.

• Save to connected charger: "When the settings are to your liking, make sure to press x and enter to save them to the connected charger."

Safety Considerations for MPPT Configuration

Working with solar charge controllers and battery systems involves electrical hazards. Always prioritize safety.

• Disconnect Power: Before making any physical connections or disconnections, isolate all power sources to the MPPT, including the solar array and the battery.
• Insulated Tools: Use insulated tools to prevent accidental short circuits, especially when working near battery terminals. A spanner across a battery bank can short hundreds of amps, causing severe burns or equipment damage.
• Eye Protection: Wear appropriate eye protection when working with batteries, particularly lead-acid types, to guard against acid splashes.
• Ventilation: Ensure adequate ventilation, especially if configuring equalization for flooded lead-acid batteries, as this process can produce hydrogen gas, which is highly flammable.

When to call a technician instead

While basic configuration can often be done by the user, there are situations where professional assistance is advisable. If you are unsure about any electrical connections, battery chemistry requirements, or if your system is not performing as expected after configuration, contact a qualified solar technician. Incorrect settings can damage batteries or other system components. Always refer to your specific product manual for detailed instructions and safety warnings.