• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 64 subscribers
  • Views 547 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ27Z561-R2: SOC drops issue

Statham Su
Genius 4990 points
Part Number: BQ27Z561-R2
Other Parts Discussed in Thread: BQ27Z561

Hello Sir:

Please refer our log file and gg file.

0116.log

0117.log

charge0116.log

20230118.gg.csv

We follow below link recommend, change the load select to User Rate-CW.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1181184/bq27z561-r2-soc-drops-issue

But after 8 cycle, the SOC drops.

Please kindly provide your recommendations and let us know how to set the load mode/load select in this application will be better.

Looking forward your feedback.

Thanks a lot.

  • 0
    TI__Guru 57697 points

    Hello Statham,

    I checked the settings and log files. The user rate is set to -600cWh and i would expect the battery to report lower capacity from the beginning, however it did the exact opposite.

    I also noticed that the load is a pulsed load. So the following section in the TRM will apply. The Min Delta voltage parameter may need to be set correctly.

    Pulsed Load Compensation and Termination Voltage — To take into account pulsed loads while calculating remaining capacity until Term Voltage threshold is reached, the bq27z561 monitors not only average load, but also short load spikes. The maximum voltage deviation during a load spike is continuously updated during discharge and stored in Delta Voltage, with the minimum value allowed set in Min Delta Voltage. Delta Voltage is added to Term Voltage to determine end-ofdischarge voltage (EDV).

    The value of Delta Voltage is 0 in the gg.csv file, this may not be right.

  • 0 in reply to Shirish
    Genius 4990 points

    Hello Shirish:

    They were using ChemID 2107 before.

    I ask customer to recheck the ChemID, and GPC report shows 2133 will be the best choice.

    4721.Config-report.zip

    About this case can we recheck and provide summary for them?

    1. Base on the ID 2133 to rebuild golden learning, because the GPC report has no 2107 item.

    2. Load mode set to constant current (load mode=0), load select set to 7 (Max Avg I last Run).

    3. I saw that discharging current avg is around 125mA, and max discharging current is 1200mA, and how to define the delta voltage will be better?

    4. Did you have other recommendations, customer wants to speed up fix this issue.

    Looking forward your feedback.

    Thanks a lot.  

  • 0 in reply to Statham Su
    Genius 4990 points

    Hi Shirish:

    We need your recommend.

    Looking forward your feedback.

    Thanks a lot.

  • 0 in reply to Statham Su
    TI__Guru 57697 points

    Hello Statham,

    Use the matching ID 2133 and i think the issue will be resolved.

    Terminate voltage is set a 2800mV in the gg.csv file, so the drop to zero was not triggered by terminate voltage. It was for some other reason which is very likely to be chemID mismatch.

  • 0 in reply to Shirish
    Genius 4990 points

    Hi Shirish:

    There has newest tested result which is not good for customer.

    Please refer these attached files, that are log file and gg file.

    0216.xlsx

    0217.log.xlsx

    20230218_statham checked.gg.xlsx

    I have a lot of questions which shows in the ppt.

    checked results_statham.pptx

    Please help to check these files and provide your recommendations for us.

    Looking forward your feedback.

    Thanks a lot.

  • 0 in reply to Statham Su
    TI__Guru 57697 points

    Term voltage is set at 2800mV in the gg.csv

    I am not seeing the voltage drop below that in the ppt graph