• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 237 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.

BQ34Z100: Remaining Charge Capacity is varying on disconnect and reconnecting the battery

Sudha Nayak S
Intellectual 380 points
Part Number: BQ34Z100
Other Parts Discussed in Thread: BQSTUDIO

Hi,

We are using 3S1P Panasonic battery(NCR18650GA) with 3450mAh capacity. We have completed the learning cycle with update status value as 0x06.

After that we have fully charged the battery and we have got Full Charge capacity as 3313mAh and SOC was 100%. For checking purpose we have disconnected the battery for 10sec and reconnected it and we have found remaining charge capacity dropped to 2419mAh and SOC is 74%. We have tried this experiment couple of time and each time remaining charge capacity was varying. 

Please find the attached log file, .csv file and screenshot.

AFTER_LERNING_CYCLE.csvlearning_cycle_w.gg.csv

Please guide us to understand why sudden change in remaining charge capacity on disconnect and reconnecting the battery  and what steps we need to follow to get exact SOC.

Best Regards,

Sudha Nayak

  • 0
    TI__Guru** 105600 points

    Hello Sudha,

    If you are disconnecting the battery from the gauge and the gauge losses power, then the gauge will correlate the voltage to a SOC value using the chem ID, so if you have a bad chem ID match this could cause it. Also if you just discharged the battery and the voltage is still recovering and then you connect the gauge is will correlate the voltage to an incorrect SOC. The battery voltage should be relaxed when the gauge is connected back.

    Sincerely,

    Wyatt Keller

  • 0 in reply to Wyatt Keller
    Intellectual 380 points

    Hi Wyatte,

    For Panasonic (NCR18650GA)battery we are using manufactured Chem ID which is same as in BQStudio ie 0x2107, so how is it possible to have a bad Chem ID?

    Best Regards,

    Sudha Nayak

  • 0 in reply to Sudha Nayak S
    Intellectual 380 points

    Hi Wyatte,

    Any update on this?

    It is not possible to continuously supply power to gauge and the Chem ID we have got from manufacturer, using that we have completed the learning cycle. So please guide us to get proper SOC and remaining charge capacity.

    Thanks and Regards,

    Sudha Nayak

  • 0 in reply to Sudha Nayak S
    TI__Expert 3030 points

    Hi Sudha,

    Current is flowing when you connected and disconnected the battery, battery voltage is also changing. Please make sure battery is relaxed before disconnecting if you don't want SOC to change.

    Best Regards,
    Abraham