BQ40Z80: BQ40Z80 IC Issues and Queries

Hi Ramana,

Ramana Murthy said:

LED Display Function:
The LED display connected to the BQ40Z80 IC doesn't work after disconnecting and reconnecting the battery. However, the display starts functioning after resetting the BQ40Z80 IC through BQ Studio.
Is there a way to reset the BMS using a physical hardware switch to avoid relying on a software reset?

The only way to create a reset from the hardware side is to cause a power on reset by removing power from the system. Can you please tell me more about the LED issue being seen here?

Ramana Murthy said:

Hardware Reset for BMS:
How can I configure the system to perform a reset on the Battery Management System (BMS) using a dedicated hardware switch instead of relying on software?

From a gauge perspective, I believe the SHUTDN pin functionality could be helpful here. More information about the pin can be found below:

Ramana Murthy said:

Emshut Down Pin (Pin 17):
I am not measuring any voltage on pin 17 (Emshut Down). Despite the lack of voltage, the switch appears to be functional as it can turn charging and discharging MOSFETs on and off.
Could you provide some debugging tips to understand why there's no voltage on this pin?

Can you please share the .gg file of the gauge so we can ensure the configuration for this functionality?

Ramana Murthy said:

Balancing Feature Verification:
How can I verify if the cell balancing feature of the BQ40Z80 is functioning properly?

I believe this can be done by following the voltage of the cells while the gauge is charging (or in relax if configured for CB in relax). If you share a log file we can get a better idea if this is being done correctly.

Ramana Murthy said:

Comparing Parameter Configuration Files:
Is it possible to compare parameter configuration files (specifically .srec files for the BQ40Z80) to identify any differences or inconsistencies?

Are you trying to compare the current parameters for the gauge in use with another from a different system? I believe this would be difficult since the parameters vary greatly from application to application. 

Regards,

Anthony 

Hi,

Attached are the log file and SREC file.

Kindly share your valuable feedback.

Best regards,BMS Test File.gg.csvtesting 40A.log
Ramana

Hello Ramana,

Anthony is currently out of office. He should get back to you next week.

Regards,

Adrian

Hi Ramana,

Looking into this .gg file sent, I see that the Update Status register is 0. Can you confirm that a learning cycle has been completed on this gauge?

Regards,

Anthony

Hello Sir,

No, I have not completed the learning cycle yet.

At an 8A load current, I can turn off both the CHG and DSG MOSFETs using the EMSHUT pin push button. However, I am unable to turn them on at full load (8A) using the same EMSHUT pin push button.

Without a load, I can turn both on and off using the EMSHUT pin push button.

In the same scenario, I am able to successfully turn on FET Enable, CHG, and DSG MOSFETs using BQ Studio with an 8A load.

Best regards,
Ramana

Hi Ramana,

Ramana Murthy said:

No, I have not completed the learning cycle yet.

Understood, for cell balancing to be active a learning cycle needs to be completed for the cell.

Ramana Murthy said:

At an 8A load current, I can turn off both the CHG and DSG MOSFETs using the EMSHUT pin push button. However, I am unable to turn them on at full load (8A) using the same EMSHUT pin push button.

Can you please confirm if the debounce delay of 1s is being seen by the shutdown pin at this time? Can you also confirm whether there are any protections triggered at this time as well?

Regards,

Anthony