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bq20z90 issue

Other Parts Discussed in Thread: BQ20Z90

Hi,

I would like to ask about the bq20z90 issue.We found some different issue when engineering run.We already try to program the bq20z90 board using Bqtester station ,Bq multistation and ROM file. After program a few board,we use bq evaluation to communicate with our board,and key in some command 0041,0021and 0020,but  we found that some unit flags are different ,mostly is VOK,ChgM,AM,and ICC, some flags turn green(0) ,some flags turn it to red(1).Please refer to below question:-

1) operation status,for the VOK flags,it need to turn to 1 or 0, to consider it is in good condition.

2) Battery mode, the ChgM ,AM, ICC flags need turn to 1 or 0 ,to consider it is in good condition.

  • I will check this next week.
  • Hi Thomas,

    Hopes to hear you.

    Thanks

    Regards,
    Loon
  • Here is some information on these flags.

    VOK: This flag is typically set after the IT Enable command has been send, but a reset will clear it.
    ChgM: This flag is set if broadcast mode is disabled. The user will decide the state.
    AM: This flag is set if broadcast mode is disabled. The user will decide the state.
    ICC: This flag should be set.
  • Hi Tom,

    For the VOK flags we observe that ,after we charge until it reach 50% and above,then we IT enable it,the VOK turn back to become high. Is there any setting saying that we have set above 50% then only the VOK can turn back to become high or is this fix setting in the bq20Z90?

    Another few more things need your help clalify:
    1) Can we manually load in the ROM using bqeasy?
    2) For 1st tier and 2nd tier over current cutoff ,we observe that,when plug the EV2300 to the board with PC,the cut off time is OK ( as per setting 2sec).If without EV2300 , the cut off time become 30~40sec. Is this correct or is there any setting we can do improve on it.
    3) For the recovery time also happen ,as per we setting current recovery time is 8sec, but it need to take about 20sec to recovery back.It is anyway to improve it.

    Thanks.

    Regards,
    Loon
  • You should not send the IT Enable command when the pack is charging or discharging. You can set it during the rest period. The VOK flag will clear if the voltage is disqualified for a Qmax update. This can occur during the optimization cycle. It should not occur after the optimization cycle has completed, but it could indicate that the ChemID is not a good match.

    1) You should be able to load the .rom file using bqEasy.
    2) and 3) The device may be in Sleep mode and only checking the current every 20s.
  • Hi Tom,

    The Chem ID is set accordingly ,but the VOk will only light up with two condition:-
    1) if we charge the batt pack above 50% , then enable it, Vok can turn it to high(red).
    2) if we charge the batt up to 50% and left it for a few hours without charging/discharging, the Vok can updated automatically and turn it to high(red).

    Is this observation in this two condition correct?

    We have another question on discharge cut off time and discharge wake up:-
    1) 1st tier cut off time - we set 2s , actual measurement that we measure using oscilloscope are 3s( delays 1s).
    2) 2st tier cut off time - we set 1s , actual measurement that we measure using oscilloscope are 2s( delays 1s).
    3) After short circuit occurs, the fuel gauge reading become 0%, it only return back the normal reading only if we discharge for awhile,is this correct.
    For OC and SOC ,the cut off timing are OK. Can you help to advise on this.


    Thanks.

    Regards,
    Loon