Connecting BYD Battery-Box LVL/LVS to Victron Energy Systems

Key Takeaways

• A Victron GX device is essential for BMS-Can communication with BYD Battery-Box LVL/LVS batteries.
• Specific CAN-bus cabling and a terminator are required for proper communication.
• All Victron and BYD components must have up-to-date firmware for compatibility.
• BYD Battery-Box Premium HVS and HVM models are not compatible with Victron systems.

How do I connect BYD Battery-Box LVL/LVS batteries to a Victron system?

Connecting BYD Battery-Box Premium LVL and LVS batteries to a Victron Energy system requires careful attention to cabling, firmware, and configuration settings. The core of this integration relies on CAN-bus communication between the BYD Battery Management Unit (BMU) and a Victron GX device, such as a Cerbo GX. This setup allows the Victron inverter/charger to receive critical information from the BYD battery, including charge and discharge limits, State of Charge (SoC), and error codes, ensuring safe and efficient operation.

Initial Setup and Diagnosis

Before troubleshooting, ensure all physical connections are secure and that both Victron and BYD components have the necessary firmware. The Victron GX device acts as the central communication hub.

Essential Components and Firmware Checks

1. Victron GX Device: A GX device is essential for BMS-Can connection. It handles the keep-alive signal, communicates charge/discharge limits, error codes, and SoC.

• • For B-Box Pro models, the GX device firmware must be a minimum of v2.42.
  • For B-Box Premium LV batteries, the GX device firmware must be a minimum of v2.52.

2. BYD BMU Firmware:

• • For B-Box Pro models, the BYD B-Box Pro BMU firmware needs to be a minimum of V4-13 (which appears as v4.13 on the GX device).
  • For B-Box Premium batteries, the battery firmware should be no less than V1.4, and the BMS firmware no less than V1.3.

3. Victron Inverter/Charger Firmware: MultiPlus, Quattro, or RS inverters require a minimum firmware version 469.
4. CAN-bus Cabling: Use a VE.Can to CAN-bus BMS type A Cable (ASS030710018). Connect the side labeled "Battery BMS" to the BYD BMS and the side labeled "Victron VE.Can" to the GX device.
5. VE.Can Terminator: A VE.Can terminator is required in the other unused VE.Can socket on the GX device to complete the communication circuit.
6. Solar Charger Connection: For proper charge current and voltage regulation, connect your Victron MPPT Solar Charger via VE.Direct or VE.Can to the GX device. This ensures the GX device can manage charging based on BYD's recommendations.

Troubleshooting Communication Issues

If your BYD battery is not visible on the GX device or communication is intermittent, follow these steps:

1. Check BYD System Status: Observe the RUN LED on the BYD BMU.

• • If the BMU LED is blinking once every second, focus on the communication with the inverter.
  • If the BMU LED is blinking more than once (2, 3, or 4 times), focus on the ADDR settings and communication cables between the batteries and the BMU.
  • If a battery module's SOC LED is scrolling side to side, review the ADDR setting for that module and check or replace its communication cables.

2. Verify Firmware Versions: Ensure all components meet the minimum firmware requirements listed above. Outdated firmware is a common cause of compatibility issues.
3. Inspect CAN-bus Cabling: Confirm the VE.Can to CAN-bus BMS type A Cable is correctly connected and undamaged. Ensure the VE.Can terminator is in place on the GX device.
4. BYD System Restart: If communication issues persist, try restarting the BYD system. Power down all modules by pressing the reset button for 5 seconds until the ARM LED flashes. Then, power up the modules by pressing the reset button briefly.
5. GX Device Configuration: Ensure the CAN-bus profile on your GX device is set correctly. Navigate to Settings -> Services -> CAN-profile and select CAN-bus BMS (500 kbit/s).

Common Faults and Solutions

This table outlines common symptoms encountered when integrating BYD Battery-Box LVL/LVS batteries with Victron systems, their likely causes, and recommended fixes.

Pairing and Settings Configuration

Correct configuration of your Victron system is crucial for seamless integration with BYD Battery-Box LVL/LVS batteries. This involves settings in VEConfigure for your inverter/charger and on the GX device itself.

GX Device Configuration

These settings are accessed through the GX device menu.

VEConfigure Settings (General Tab)

These settings are applied to your Victron MultiPlus or Quattro inverter/charger using VEConfigure software.

VEConfigure Settings (Charger Tab)

These settings define the charging parameters for the inverter/charger.

VEConfigure Settings (Inverter Tab)

These settings manage the inverter's DC input behavior.

VEConfigure ESS Assistant Settings

If you are using an Energy Storage System (ESS) with your Victron setup, these settings are critical.

Victron MPPT Charger Settings

For Victron MPPT solar chargers, configure these settings using VictronConnect.

Safety Considerations

Working with high-voltage battery systems requires strict adherence to safety protocols. Lithium batteries, while generally safe, can pose risks if mishandled.

• Over-current Protection: Using very large solar arrays with undersized battery banks can exceed charge limits and trigger BMU over-current alarms. Ensure your system is properly sized.
• DC Input Low Shutdown: The inverter/charger will shut down at 47V DC input to protect the batteries from over-discharge.
• Battery Self-Protection: If a battery becomes completely discharged, it will disconnect DC voltage from its terminals via internal MOSFETs as a self-protection measure.
• Cold Weather Performance: BYD cells limit charge current at lower temperatures to prevent damage. For optimal performance and longevity, keep batteries in a climate-controlled environment.
• BYD B-Box Pro Cabinet Limit: The 125A circuit breaker in IP55 BYD cabinets (B-Box Pro models) can be overloaded if four modules (140A combined) are used. Limit the DVCC distributed charge current to 120A per cabinet to prevent this. If using multiple cabinets, additional circuit protection is required at the DC bus level.
• Operating without BMU: Never attempt to operate battery cells normally without a connection to the BMU. The BMU is critical for managing the battery's health and safety.

For general information on battery systems, explore our batteries category.

When to call a technician instead

While many configuration and troubleshooting steps can be performed by the user, some situations require professional intervention.

• Persistent BYD System Errors: If the BYD system reports internal errors (e.g., "Max Charge Voltage 42 V") that cannot be resolved by checking wiring or addressing, contact BYD support.
• Complex Firmware Updates: While Victron firmware updates are often straightforward, BYD BMU and BMS firmware updates can sometimes be complex. If you are unsure, consult a certified BYD or Victron technician.
• Physical Damage: Any signs of physical damage to battery modules, cables, or the BMU warrant immediate professional assessment.
• Unresolved Communication Issues: If, after following all troubleshooting steps, your Victron and BYD components still fail to communicate reliably, a technician can diagnose deeper electrical or software issues.
• Warranty Concerns: Attempting unauthorized repairs or modifications may void your warranty. When in doubt, especially for new installations, contact your installer or a certified technician.