BQ40Z80: Learning cycle failed , stuck in LStatus()not change to 06 and VOK not clear

Jeckson lee

Intellectual 280 points

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO,

Dear TI‘ Team

I have failed twice when doing learning cycle, both are stucked in the step discharging to empty and wait VOK clear.

My application is a 7S1P pack, the battery is EVE ICR18650-26V , the GPC match the ID 1783 as the report show.

Can anyone help me to check which step or details gose wrong?

the log is :

3808.log.zip

the screen shot of BQstudio is:

and the cycle curve is:

over 5 years ago

0 Jeckson lee over 5 years ago

Intellectual 280 points

upload data flash log :

DF_LOG.zip

0 Wyatt Keller over 5 years ago in reply to Jeckson lee

TI__Guru** 105760 points

Hello Jeckson,

We'll look into the problem for you.

Sincerely,

Wyatt Keller

0 Luis H. S. over 5 years ago

TI__Mastermind 42060 points

Hello Jeckson,

Can you try following the GPCCHEM process and learning cycle process again to see if the issue gets resolved.

Regards,

Luis Hernandez Salomon

0 Jeckson lee over 5 years ago in reply to Luis H. S.

Intellectual 280 points

Hello Luis

Thank you for reply

This is the GPC file I did several days ago and report back to me, do you mean I need do it again? :

4426.GPCPackaged-report.zip

1055.GPCPackaged.zip

0 Luis H. S. over 5 years ago in reply to Jeckson lee

TI__Mastermind 42060 points

Hello Jeckson,

It seems that the learning cycle failing to update to 06 can be caused due to poorly matched chemID. But your GCP report seems to be ok.

Did you follow the procedure detailed in How to Complete a Successful Learning Cycle for the bq40z80? Let me know if you've already followed this procedure.

Best Regards,

Luis Hernandez Salomon

0 Jeckson lee over 5 years ago in reply to Luis H. S.

Intellectual 280 points

Hello Luis

I think I followed the procedure :

1) GAUGE_EN and RESET

2) discharge to empty ( FD set to 1)

3) Relax for VOK clear and REST auto set (maybe 2 hours , not 5 hours as required )

4) charge to full (FC auto set to 1)

5) Relax 2 hours and REST auto set to 1,and VOK clear , Lstatus() update to 05.

6) discharge to empty (FD auto set to 1)

7) wait for long enough and find REST and VDQ auto set to1 but VOK did not clear, and Lstatus() failed update to 06.

As your advice, I did the GPC cycle again , but this time the best match ID is 497,, the second match ID is 1783( ID 1783 match the battery which I used, EVE ICR18650-26V)

3326.GPCPackaged-report.zip

0312.GPCPackaged.zip

the battery datasheet :

《EVE ICR18650-26V RD-EVE ICR18650-26V-S38-LF.pdf

Some information :

1) As I did the cycle several times, I found the 4th cell always reach the Term Voltage fast than other cells in discharging ,that is normal??

0 Luis H. S. over 5 years ago in reply to Jeckson lee

TI__Mastermind 42060 points

Hello Jeckson,

Your procedure for the learning cycle seems to be good. It is recommended to use the ID with the lowest DOD error given by GPCCHEM. Could you try doing the cycle again with this new ID?

1) As I did the cycle several times, I found the 4th cell always reach the Term Voltage fast than other cells in discharging ,that is normal??
The 4th cell reaching Term Voltage faster might be due to having a lower State of Health than the other cells.

2) the Term Voltage is set to 2900mV , the cut off voltage is 2500mV as the battery datasheet shows. dose this matter? I tried the setting with 2500mV ,but as the 4th cell will reach to it earlier than other cells ,when the pack empty ,it will lead a CUV alarm
2900mV should be fine, you could try lowering it 100mV more. According to the Technical Reference, the threshold for the CUV alarm is 2500mV, which is probably why it is being triggered when you set it at that point.

Best Regards,
Luis J. Hernandez Salomon

Power management

Power management forum

BQ40Z80: Learning cycle failed , stuck in LStatus()not change to 06 and VOK not clear