• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 132 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: The CHG bit of Flags is always high.

ochul kwon
Prodigy 80 points
Part Number: BQ34Z100
Other Parts Discussed in Thread: BQSTUDIO

Tool/software:

I completed the learning cycle using the LFP battery.
I created a golden image, created an srec file, and downloaded it to another board and am using it.
During use, the battery power was disconnected, so I downloaded the golden image again and calibrated the CC Offset, current, voltage, etc.
From here, the current is different from the actual measured value, and the CHG bit of the Flags is always high.
The actual current consumption measured with a current meter is 4A, but it is less than 1A in Bqstudio. What is the problem that the CHG bit is always high when the power is connected only to the BQ34Z100???

  • 0
    TI__Mastermind 25725 points

    Hello Ochul,

    What is your GPC selection tool error % difference with your cell, it should be below 3% before you would need to get a custom chemID made. It seems that your scaling on your pack is off within your system and this could lead a a CHG bit being flagged as high. I would also still review your charge subclass register to confirm that your system is not going out of bounds aswell. 



    Thank you,
    Alan

  • 0 in reply to Alan Frias
    Prodigy 80 points

    GPC is using 400.
    There is a deviation of about 9%, but there was no problem with the learning cycle and use.
    The important point is that I have been using the battery gauge normally until now.
    I re-downloaded the golden image and then the problem occurred.
    The current consumption is expressed as about 12.5% ​​of the actual measurement. (8 times difference)
    And the charging bit is always on while discharging.

  • 0 in reply to ochul kwon
    TI__Mastermind 25725 points

    Hello Ochul,

    That is unexpected that your battery gauge can pass the learning cycle with a deviation of 9%, the most that would be acceptable is 5% (only with the programmed ChemID battery gauge) and even then that would be a stretch and would need some work on the backend. What most likely is happening is proper calibration in the calibration tab wasn't performed before correctly leading to a bad ChemID and a false pass on the cell learning cycle. I would redo calibration and see if you can get a lower value difference in ChemID afterwards. Worst case scenario you would need to contact your local Texas Instruments FAE to get your battery cell characterized. What type of cell chemistry are you using within the system.

    Thank you,
    Alan