Troubleshooting Steps for BYD HV Batteries – CAN COMM Fail

Modified on Fri, 29 Sep 2023 at 01:21 PM

Note: Before starting troubleshooting, make sure that the CAN cable used is Cat6 or above and that the cable provided with the S6 device is not suitable for BYD connection. 

Also, ensure safety precautions are followed while working with electrical components.


Battery Side:



Install "Be Connect" App:


Download and install the "Be Connect" App on your phone.

Configure the battery via the app and ensure that the latest firmware is installed on the battery.

After configuring, start the battery (inverter should be "off"). The blink code on the battery should display 11 times in blue and one time in white if it's ready to communicate.



CAN Connection Between Inverters:

Refer to the instructions provided by BYD for proper CAN connection.

There are two possible connection options (Option A and Option B). If Option A doesn't work, try Option B. please make sure that the PIN assignment is correct.

Battery side: PIN 1 and 2

Inverter side: PIN 4 and 5

Option A:


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Option B:


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If the error persists, attempt to change the cable connections on PIN 1 and 2 on the battery side. Refer to the provided image or instructions.

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Ensure CAN Connection is Earthed:

Verify that the CAN connection is properly earthed to prevent grounding issues.

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 Please ensure that the switch is in the correct position, as shown below (for a one-battery system).

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Further Troubleshooting on Battery Side (if needed):


A. Battery Cover Closure:

Ensure that the battery cover is securely closed.

If connection issues persist, use a cable tie to attach the metal contact to the plug as shown in the provided picture.

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B. Grounding Disconnection:

If problems persist, disconnect the grounding as indicated in the provided picture (yellow marker).

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C. Tin Cable Ends (if using PIN block):

Consider tinning the cable ends to improve contact (if PIN block is used on the battery side).



Inverter Side:


Check Inverter Readiness:

To check if the inverter is ready to communicate, measure 2.1V between PIN 2 and PIN 4 or 5.

Refer to the provided video for guidance and ensure to take photos of the measurements for reference.

Video Link:



Important Restart Steps:


Shutdown Sequence:

A. Turn off the system in the following order: set "Grid Off" on the inverter menu, then switch AC off, followed by the battery, and finally PV.

B. Wait for at least 2 minutes before proceeding to switch the system back on.


Startup Sequence:

A. Switch on the system in the following order: first the battery, then PV, and finally AC.


If Issues Persist:


If the problem persists after attempting all the troubleshooting steps above, please contact the Solis Support team.

When Contacting Customer Support provide the following information:


1: Serial number of the device.

2: Which Battery model is used

3: Detailed information about which troubleshooting steps have been taken.

4: Photos of the installation setup.

5: Photos of the measurements taken (2.1 volts on the inverter side).

6: Current Firmware installed on inverter side (HMI and DSP Version)


Contacting customer support with these details will help them assist you more effectively in resolving the issue.

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