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BQ78350-R2-DEVICE-FW: Is COT allowed during data logging for GPC?

Part Number: BQ78350-R2-DEVICE-FW

In my application, especially for the high temperature range battery can go into Cell Over Temperature protection, disable the discharge and continue after recovering. Is it allowed during data collection for GPC?

Otherwise I will pick a high current value that is smaller and does not trigger COT during discharge in high temperature range.

  • Hi Mehmet,

    For GPC, it is best to adjust protection thresholds or disable some protections since it is important to collect accurate continuous discharge curves. The GPC data does not even need to be collected using the BQ78350, it just needs to college voltage, current, and temperature data.



  • Hi Matt,

    I think I am cornering the GPC packaging topic. I dig through all data I could find, but I have further uncertainties. Could you please confirm or correct my understanding in the following lines:

    1. I am setting FCC learning based on a single cell measurement which is minimum of all series connected cells (cell islands, cell blocks as I also have parallel connected cells in each block). Hence, 

    1.a. I must give minimum single cell voltage in mV to GPC.Exclamation

    1.b. I must still choose # of series connected cells as total number of cells connected in series, e.g. 12. (it is ) Exclamation

    2. What is really CellTermV QuestionHow does it relate to CUV, EDV0 and ReserveCapacity QuestionMy understanding is as follows:

    2.a. CellTermV is desired EDV0 where battery will report 0& SoC. Exclamation

    2.b. CUV can be (maybe even enciraged to be) lower than EDV0 to have some ReserveCapacity when SoC reaches 0%. Or even to prevent premature disbling of discharge under high pulsed loads (e.g. a high load kicking in when voltage is close to EDV0) and BMS triggring CUV to disable the discharge before SoC reaches 0%. Exclamation

  • Hi Mehmet,

    1 - The GPC log file will need to total pack voltage and the # of series cells (it will divide the total voltage by the number of cells). See the example near the end of this app note: 

    2- The CellTermV is the minimum voltage for your system. CUV will typically be set lower than this voltage and is based on the recommendation from the cell manufacturer. CellTermV is more related to the electronics in your system, so your 0% SOC.

    Best regards,