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BQ40Z80: High current charger

Danilo A.
Mastermind 28710 points
Part Number: BQ40Z80

Hi Team,

A customer is looking for a high current charger that could charge 7S2P 6.6Ah LiPo at 140A for 45sec. Can BQ40Z80 charge 7S2P batteries at 140A? If not, do we have a charger that can charge at 140A?

Regards,

Danilo

  • 0
    TI__Mastermind 42060 points

    Hello Danilo,

    The BQ40Z80 is a battery pack manager that serves as a gauge with numerous protections. It is not a charger, you would have to get a charger alongside the BQ40Z80. Also, 140-A current might be too high for accurate current measurements in the BQ40Z80.

    I will place this thread to the application engineers that are familiar with charging products, in order to assist you in finding the right charger for your customer's application.

    Best Regards,

    Luis Hernandez Salomon

  • 0 in reply to Luis H. S.
    TI__Guru**** 166826 points

    Hi Danilo,

    TI does not have a single charger IC that provides 140A into a 7S2P LiPo pack.  I recommend searching the reference designs at the link below for multi-chip reference design.

    https://www.ti.com/reference-designs/index.html

    Regards,

    Jeff

  • 0 in reply to Jeff F
    TI__Mastermind 28710 points

    Hi Luis and Jeff,

    Thank you for your response. 

    Do we have an alternative device to BQ40Z80 that can monitor cell voltages, temperatures, and possibly balance cells while using a charger that supplies 140A?

    Regards,

    Danilo

  • 0 in reply to Danilo A.
    TI__Mastermind 42060 points

    Hello Danilo,

    The Coulomb Counter ADC of the BQ40Z80 has a range of -0.1-V to 0.1-V. If you adjust your sense resistor to (100-mV)/(140-A) = 0.71-mOhm. You could use the BQ40Z80 with a charger that supplies 140-A. However, there will be issues with resolution and offset errors when trying to measure low currents. We usually recommend to use a sense resistor within a 1-mOhm to 3-mOhm range.

    According to the datasheet of the BQ40Z80, the Coulomb Counter's ADC has a max of 10-uV offset error. If using a 0.71-mOhm resistor, you'd have a 14-mA offset error. You'd also have a ADC current resolution of ~8.54-mA. So the gauge would not work well on these ranges.

    If you won't have currents in that range. You can use the BQ40Z80 with a 140-A current charger.

    Best Regards,

    Luis Hernandez Salomon

  • 0 in reply to Luis H. S.
    TI__Mastermind 28710 points

    Hi Luis,

    Thank you very much for sharing this valuable information.

    Regards,

    Danilo