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BQ40Z50-DEVICE-FW: Learning cycle data when IT is disabled

Part Number: BQ40Z50-DEVICE-FW

Tool/software:

Hello forum.

I have a rather special question for a specific use case in which it is desired to limit the battery voltage from the normal operating voltage limit.

Say that I for protection reasons wants to limit the battery operating voltage from the normal operating range (3.0V - 4.2V) to something like 3.0V - 3.8V. In this reduced voltage operation range:

  • I want to display the new max voltage, 3.8V, as 100% SoC instead of 4.2V
  • I do not want the Impedance Tracking / learning algorithm to use any data in this stage for improving its learning registers.

My question is therefore: Can the above be accomplished, where the learning algorithm of the BMS ignores the reduced operating range until this mode is exited? Will the learning algorithm / IT data be preserved when going back to normal mode?

Ignore the transition between these two stages for now, e.g. if the battery voltage is above the new operational limit, this will most likely be fixed through a burn script when entering this mode.

Hope the above makes sense, and please reach out to me if anything needs to be elaborated.

Thanks in advance

Kind regards,
Victor

  • Hello Victor,

    I am not familiar with anyone doing something like this, so it will be interesting if you did testing on this.

    You should be able to configure 100% SOC at any voltage you like by making the correct configuration for Valid Charge Termination.

    You will need to focus on the condition regarding voltage.

    Then, I believe you should be able to send the "GAUGE_EN" command, if impedance track was enabled before then sending the command should disable it. However, I am not sure if doing this will still cause the gauge to report 100% for your new valid charge termination conditions.

    Regards,

    Adrian

  • Hello Adrian.

    Thank you for the reply, I will give this a try and look at the result, although it may be a while before testing begins due to the upcoming holidays.
    Thank you for the support regardless :)

    Kind regards,
    Victor