Victron Freedom Won Lithium CAN-bus Configuration Guide

Key Takeaways

• CAN-bus baud rate mismatch is a primary cause of communication failures between Victron GX devices and Freedom Won batteries.
• Always confirm the CAN-bus profile on your Victron GX device is set to "CAN-bus BMS (500kbit/s)".
• Incorrect charge voltage settings can severely damage lithium batteries; use the manufacturer's specified values.
• If communication issues persist after checking all basic settings and connections, or if you have a multi-battery setup with a Color Control GX, professional assistance is required.

Why isn't my Victron GX communicating with my Freedom Won battery?

The most common reason a Victron GX device fails to communicate with a Freedom Won lithium battery is an incorrect CAN-bus baud rate or an improperly configured CAN-bus profile on the GX device. The Freedom Won Battery Management System (BMS) is configured by default to communicate over CAN bus at a 500kbps baud rate. Ensuring your Victron GX device is set to this rate and the correct CAN-bus profile is the first step in troubleshooting.

Diagnosing Freedom Won CAN-bus Communication Issues

Follow these steps to diagnose and resolve communication problems between your Victron GX device and Freedom Won lithium battery.

1. Check Physical Connections:

• • Ensure the CAN-bus cable is securely connected between the Freedom Won battery and the VE.Can port on your Victron GX device.
  • Verify the cable is not damaged and is correctly pinned for CAN-bus communication.

2. Verify Victron GX CAN-bus Settings:

• • On your Victron GX device (e.g., Cerbo GX, Color Control GX), navigate to Settings -> Services -> VE.Can port.
  • Confirm that the CAN-bus Profile is set to CAN-bus BMS (500kbit/s). This ensures the GX device is listening for the correct communication protocol and speed.

3. Confirm Freedom Won Baud Rate:

• • The Freedom Won Battery Management System is configured by default to communicate over CAN bus at a 500kbps baud rate. This should match the Victron GX setting.

4. Address Single Battery/VE.Can MPPT Scenarios:

• • If your system uses a Color Control GX and Victron VE.Can MPPTs, it is possible to change the baud rate of the BMS to 250kbps to accommodate the VE.Can baud rate. However, this is only possible with one battery on a system with a CCGX. This change must be performed by Freedom Won technical support.

5. Check for Multiple Battery Limitations with CCGX:

• • If you have multiple Freedom Won batteries (with slave batteries) in your system, the Color Control GX cannot be used. The CCGX has a single CAN bus, which leads to conflicting CAN messages when multiple batteries are present, preventing proper communication.

6. Verify eTower DIP Switch Configuration (for eTower models):

• • For Freedom Won eTower batteries in parallel, ensure the first battery is programmed as the Master by setting it to Address 01 using its DIP switches. Other eTower modules connected to the DC bus should be programmed as Slaves, typically by default when they have addresses of 02 or higher.

Freedom Won Victron Setup: Common Problems and Solutions

This table outlines specific symptoms, their likely causes, and the corresponding fixes for Victron Freedom Won battery systems.

Configuring Victron Inverter/Charger Settings for Freedom Won

Beyond CAN-bus communication, proper charging parameters are crucial for the longevity and performance of your Freedom Won lithium battery. These settings are typically configured in your Victron inverter/charger using VEConfigure software or directly on the GX device for some models.

• Absorption Voltage: Set to 55.80 V. This is the voltage at which the charger holds the battery during the absorption phase.
• Float Voltage: Set to 55.80 V. This is the voltage at which the charger maintains the battery once absorption is complete.
• Absorption Time: Set to 1 Hr. This specifies how long the charger remains in the absorption phase.
• Voltage Target: Ensure the system's voltage target, especially when nearing full charge, is within the range of 54.8V to 55.8V. Below approximately 95% State of Charge (SoC), the value reflected should be 55.7V or 55.8V. For a fully charged battery, this value should range from 55.0V to 55.8V, depending on the cell balancing.

For systems with very high charge current limits, be aware that the Victron GX controller's CAN Bus hexadecimal message format cannot accept a number larger than 6500A for the Charge Current Limit (CCL). If your system's total CCL exceeds this, you may need to contact Freedom Won technical support to reduce these limits so that the total falls at or under 6500A.

For more general information on lithium battery systems and their integration, you can explore our /pk/batteries guides.

Safety Considerations for Lithium Battery Systems

Lithium-ion batteries, like the Freedom Won series, require careful handling and correct configuration to ensure safe operation. Unlike lead-acid batteries, they do not produce hydrogen gas during charging, eliminating the need for ventilation to prevent explosive gas buildup. However, they pose other risks if mishandled:

• Thermal Runaway: Overcharging, physical damage, or internal shorts can lead to thermal runaway, where the battery overheats and can catch fire. The Battery Management System (BMS) is designed to prevent this by monitoring cell voltages and temperatures. Never bypass or disable the BMS.
• Short Circuits: A short circuit across the battery terminals can draw extremely high currents, leading to rapid heating, fire, or explosion. Always use insulated tools when working near battery terminals and ensure all power sources (PV, AC, battery) are disconnected before making or breaking connections. A spanner across a large battery bank can short hundreds of amps instantly.
• Voltage Hazards: High voltage DC systems can deliver a lethal shock. Always treat battery systems with extreme caution.

Ensure all wiring is correctly sized and protected by appropriate circuit breakers or fuses. Follow all installation instructions provided by both Freedom Won and Victron Energy.

When to call a technician instead

While many communication and setting issues can be resolved with careful troubleshooting, some situations warrant professional intervention to ensure safety and system integrity:

• Persistent Communication Errors: If you have followed all diagnostic steps and communication between your Victron GX and Freedom Won battery remains unstable or non-existent.
• Multi-Battery Systems with CCGX: If your system includes multiple Freedom Won batteries and a Victron Color Control GX, a technician will confirm the incompatibility and recommend an alternative GX device (e.g., Cerbo GX).
• CCL Limit Exceeding 6500A: If your system's total Charge Current Limit (CCL) exceeds 6500A and requires custom profile adjustments, this must be handled by Freedom Won technical support.
• Physical Damage or Unusual Behavior: Any signs of physical damage to the battery, unusual smells, swelling, or excessive heat indicate a serious problem that requires immediate professional assessment.
• Warranty Concerns: Attempting unauthorized modifications or repairs can void your battery's warranty. If you are unsure about any step, consult a qualified solar technician.