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BQ40Z80: Bq40z80 RevB

Part Number: BQ40Z80

Hi,

We want to use the Bq40z80 in one of our projects, but today we noticed that TI has made some changes in the documentation of the product.

As far as we can see, the product supports between 2 series and 6 series. Don't we have a chance to use this product in a 7 series battery?

Could you give information about the reason for this change in the IC, which has been produced since 2018 and can be used between 2 series and 7 series?

Thanks

  • Hi Yasin,

    This is because we observed the 7th cell was less accurate and could potentially cause gauging issues because it's based on resistor divider instead of direct cell measurement. You still have the option to use it as a 7S gauge, but we just want to make sure you are aware of the 7th cell. We are currently working on a new FW which will remove support for the 7th cell as well as implement some bug fixes. The existing FW on the product page for BQ40z80 will continue to support 7 series cells. 

    Thanks,

    Rushi

  • Hi Rushi,

    Thank you for your answer. I have two more questions.

    1-) How much deviation is there in the measurement of the seventh cell? What potential measurement issues do you expect?

    2-) You mentioned that TI will fix bugs with the new FW. What are the current bugs? Are there any bugs that prevent me from designing with the current FW?

    Thanks
  • Hi Yasin, 

    1) We don't have an exact number quantified on this as it can depending on factors such as temperature and resistor tolerance

    2) We have an internal document describing some of the bugs we have observed, but please connect with me and we can discuss offline by email. That way I can understand about your use case better as well and I can loop in other team members as needed. I will send you a connect request.

    Thanks,

    Rushi