• State Resolved
  • Locked Locked
  • Replies 12 replies
  • Answers 3 answers
  • Subscribers 63 subscribers
  • Views 799 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.

BQ40Z80: the learning cycle fail.

user6013621
Prodigy 80 points
Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO,

hello,

i made the battery packs, 6S2P and 6S4P Lipo battery pack.

and i have done learning cycle.

6S2P was done well.

but 6S4P isn't done. (Norminal Vol : 21.6, Capacity : 13,400mAh)

my learning cylce step below.

1. Check and write proper value of Register, Chem, Calibration.

2. After Checking, Set Gauge_EN and RDIS and Clear VOK.

3. After step 2, fully discharging battery pack.

4. Take a rest time, 5 hours (the Rest flag should be set)

5. after rest ttme, fully charge battery pack. at that time, Lstatus : 0x04.

6. Take a rest time, 2 hours

in this step, Lstatus should be 0x05. but my 6S4P Pack's Lstatus is 0x06.

what is wrong my steps?

ref > How to Complete a Successful Learning Cycle for the bq40z80

  • 0
    TI__Guru 52115 points

    Can you provide a bqStudio log file for your learning cycle so that I can check if there was something wrong with your learning cycle? 

    Also, make sure your chemistry id is proper and discharge the battery cell to the minimum voltage of the battery as specified in the manufacturer’s data sheet.

    Andy

  • 0 in reply to Andy Liu (BMS)
    Prodigy 80 points

    Thank you for reply.

    this is my log file.

    please check detached file.200407_LearningCycle_CHG.xlsx

  • 0 in reply to user6013621
    TI__Guru 52115 points

    I have checked your log file and I cannot tell whether the battery cells were discharged to empty and relaxed.

    Do you have a continuous bqStudio log for your entire learning cycle?

    Andy

  • 0 in reply to Andy Liu (BMS)
    Prodigy 80 points

    Dear Andy.

    hello,

    you mean if there are somthings wrong, example Lstatus 0x06 at Charging step, i will continue learning cycle?

    i stop the learning cylce when there are somethings wrong.

    Unfortunately, there are almost same.

    after charging and taking the rest time, the Lstatus is 0x06.

    so, if i ignore it, i can log the whole learning cycle.

    please wait a few day.

    i will log whole cycle.

    thank you

  • 0 in reply to user6013621
    TI__Guru 52115 points

    If the LStauts() is already 0x06, it means a QMax update and resistance update are both done. 

    I would suggest you run the learning cycle again so that the LStatus() changes to 14 (0x0E).  You can find these details in the app note you already have.

  • 0 in reply to Andy Liu (BMS)
    Prodigy 80 points

    Dear Andy

    i got it.

    but i don't understand.

    i know that 

    Lstatus = 0x05 -> first Qmax update occur

    i think Lstatus should be 0x05 at first charging step.

    so i changed the Qmax cycle to 0, when learning cycle failed.

    once i follow your idea that don't care about 0x05. 

    thank you

  • 0 in reply to user6013621
    TI__Guru 52115 points

    As I mentioned before,  I don't have your continuous bqStudio log so I cannot tell what happened to your learning cycle.

    If the LStatus() was only updated by the gauge itself and you never updated the LStatus manually,  your learning cycle seems done since the LStatus() is already 0x06.

      

    I would suggest you run the learning cycle again to see whether the LStatus() can change to 14 (0x0E). 

  • 0 in reply to Andy Liu (BMS)
    Prodigy 80 points

    i got what you mean.

    i think it maybe mix two battery pack(6S2P and 6S4P).

    how i can reset the learning cycle done?

    are there any way to reset learning cycle?

    thank you, Andy.

  • 0 in reply to user6013621
    TI__Guru 52115 points

    I would suggest you dump a srec file before you start the learning cycle next time.  If you want to redo the learning cycle, just program the srec file to bq40z80. 

    I guess you probably have not done it yet. I would suggest you program the default srec file to bq40z80, have the necessary settings configured (e.g. chemistry id) and then do the learning cycle again.

    Andy 

  • 0 in reply to Andy Liu (BMS)
    Prodigy 80 points

    Dear Andy

    i am doing new learning cycle.

    after downloading default firmware, i am followed the reference step.

    but, it doesn't work.

    at this challenge, i have some questions.

    1. after downloading default firmware, the 'Full charge capacity' didn't match.

    So, i have to change some register.

    a. setting -> SOC Flag Config B : 0x99

    : default setting make me can't charge my battery pack. because it isn't matched to set FC flag. So, i change the standard of FC set to Voltage level, not percentage.

    b. protection -> OC : Threshold : 10000mAh

    : default setting make me can't charge. after a little while of charging, OC Flag should set. because of capacity.

    2. after changing some parameter, i was doing learning cycle.

    but, in step 3, REST and VOK never clear.

    i don't know why.

    could you tell me the way how i match the capacity?

    thank you

    Best Regard

  • 0 in reply to user6013621
    TI__Guru 52115 points

     Do you have a continuous bqStudio log to share with me this time?

    Andy

  • 0 in reply to Andy Liu (BMS)
    Prodigy 80 points

    Dear Andy.

    Thank you!

    after downloading default firmware again, learning cycle process is done!

    however, fully capacity is too small.

    i think If i continue charging and discharging, the capacity will be better.

    thank you again.