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BQ34Z100-R2: Battery pack complete optimization procedure

Jordan F
Prodigy 30 points
Part Number: BQ34Z100-R2
Other Parts Discussed in Thread: GPCCHEM, GPCRA0, GPCRB, BQ34Z100

Tool/software:

Hello, I have some questions about what a complete optimization looks like for a li-ion battery pack. Right now, our process looks like:

GPCCHEM ID cycle: https://www.ti.com/lit/an/slva725a/slva725a.pdf?ts=1733931714286&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FGPCCHEM%253FkeyMatch%253Dgpcchem%2526tisearch%253Duniversal_search

GPCRA0 cycle: https://www.ti.com/lit/ug/sluubc9/sluubc9.pdf?ts=1733931003514&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FGPCRA0

GPCRB cycle: https://www.ti.com/lit/ug/sluubd0/sluubd0.pdf?ts=1721677479408&ref_url=https%253A%252F%252Fwww.google.com%252F

After this, we would generate a "Pre-Golden image" where we program a fresh srec file on the fuel gauge, configure the data flash parameters with pack configuration and information derived from GPCRA0 cycle, program the chemistry found by the GPCRB cycle, Calibrate for voltage & current.

Once the Pre-Golden image is saved as a .srec file, we would enable IT and run a cycle with a 1C charge, wait for OCV measurement, DSG at 1C, wait for OCV measurement, and repeat 3 times. once that is done, we would save this as our totally complete golden image.

All of these steps were taken from an internal document at our company and the author is no longer around. I havent seen all of these steps in the BQ34Z100 datasheet when its talking about running a optimization/learning cycle. Are all of these steps necessary? What is the value that is gained by running the GPCRA0 and GPCRB cycles? Will running a GPCCHEM ID and traditional learning cycle be enough for generating a golden image for a pack?

For context, this is for a 12S lithium-ion battery pack

Thanks

  • +1
    TI__Mastermind 35161 points

    Hello Jordan,

    First you sill need to use the GPCCHEM cycle to get a matching ChemID for the battery you are using.

    Then you will complete the learning cycle on the gauge. You can look over this document that talks about the learning cycle: https://www.tij.co.jp/jp/lit/an/slua903/slua903.pdf

    GPCRA and GPCRB are optional. If your application is going to be used in extreme temperatures (outside the range of between 0C and 40C) then we recommend using the GPCRB tool to optimize the gauge for extreme temperature.

    GPCRA0 is only needed if you run discharge test after completing the learning cycle and the gauge is not tracking SOC properly.

    Regards,

    Adrian

  • 0 in reply to Adrian
    Prodigy 30 points

    Hi Adrian,

    Thank you for the information. Do I need to calibrate the CC/Board Offset, Voltage, and Current as well before performing the learning cycle?

    Another question about the GPCRB test. Our cells shouldn't get below 0C, but we do have an operational range above 40C. Does the test setup in that document need to change for the higher temperature? The document only specifies a 25C (roomtemp) cycle and a 0C cycle. Should I change that to 25C and 40C? Or will the test at 0C account for both temperature extremes and give us an updated ChemID that performs better at both extremes?

    Thanks,

    Jordan

  • +1 in reply to Jordan F
    TI__Mastermind 35161 points

    Hello Jordan,

    Yes, I should have specified that calibration of the gauge is the absolute first step. 

    Yes, you can do the test at 25C and 40C.

    Regards,

    Adrian