BQ27750EVM-837： SOC not updating with BQ27750.

Hi Yan-Yu,

When the device is in its intended application, is there any relax time between the charge and discharge sessions?

Regards,

Anthony Baldino

Hi Anthony

From the lifetime assessment, only discharge has been performed.

The maximum voltage appears to be the voltage at the time of shipment.

Are there other possibilities causing SOC not to update?

Best Regards,

Yan-Yu, Tuan

Hi Yan-Yu,

Is it possible for you to provide us with a data log of this gauge?

Also, please confirm that GAUGE_EN is enabled through using the RESET command, GAUGE_EN, then refreshing the registers to see if anything changes.

Regards,

Anthony Baldino

Hi Anthony,

I understand the reasons for executing the reset command and confirming that gauge_en is enabled.

I have performed several charge and discharge cycles, and the SOC behaves normally.

However, I cannot identify the possible reasons for the anomaly at the customer's end.

If the same issue occurs again, how would you recommend I handle it?

Best Regards,

Yan-Yu,Tuan

Hi Yan-Yu,

Is it possible for us to receive a log file of this anomaly occurring? I believe this data will allow us to look deeper into why the SOC is not updating.

Regards,

Anthony Baldino

Hi Anthony

I understand checking the issue through log data.
However, when I retrieve it from the customer and perform charge and discharge cycles, the SOC performance is normal.
Is it possible to identify the problem from this log data?
I'm wondering if it's possible that leaving it idle for a period may cause the gauge IC to not immediately update SOC.
Would it be necessary to perform a cycle to update or activate Qmax or RA?

Best Regards,

Yan-Yu,Tuan

Hi Yan-Yu,

Understood, thank you for clarifying the issue.

Can you please tell us if there are any differences in the how charge/discharge cycles are being completed, parameters being changed, or different process's that are occurring between how the customer is using the device and you are?

We believe there could be a difference in method due to it working for you after the customer returns it.

Regards,

Anthony Baldino

Hi Anthony

I determined that the batteries were stored in the customer's warehouse for approximately half a year after shipment.

Only recently, when they were taken out for use, issues were discovered. I confirmed from the Lifetime that the maximum voltage is only 3.5V, suggesting that

the batteries have been left unused for some time.

However, I shipped a significant quantity, and currently, only one has been found with this issue. This is the current information I have.

Thanks

Best Regards,

Yan-Yu,Tuan

Hi Yan-Yu,

Is it possible to receive the register read out of right when the unit from the customer was received?

Also, can you please tell us how many total units were shipped out?

Regards,

Anthony Baldino

Hi Anthony

1) I use BQ Studio to read the Pack, everything is normal.

2) around 4K.

Best Regards,

Yan-Yu,Tuan

Hi Yan-Yu,

If there is another case of this anomaly occurring, please log the immediate read out from the device so we can try to debug what might be causing this situation.

However, we do not believe there is enough information that could lead us to a reason this is occurring without understanding what is happening on the customer side with the device.

Regards,

Anthony Baldino

Hi Anthony

I understand.

Thank you for your help.

If there are new issues, I will consult with you.

Thanks!

Best Regards,

Yan-Yu,Tuan