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BQ34Z100-G1: high cells count battery pack

Part Number: BQ34Z100-G1

Good morning,

I need to use a gas gauge component for monitoring SOC and SOH of an high cells count NiMH battery pack.

I'm talking about 50S-60S configuration, with a maximum voltage around 96V (by considering a maximum full charge voltage of 1.6V/cell).

By following the SLUA760 indications, it should be possible to configure and properly calibrate the BQ34Z100-G1 for such an application, but I would like to ask for a confirmation about that.

Moreover, also current and capacitance exceed maximum allowed values for BQ34Z100-G1 (current up to 100A average and 150A peak; capacity up to 80.000mAh), but also such constraints can be bypassed by following the SLUA760 and specific instructions reported in the component datasheet.

Please anybody can point out just in case there is any critical issue concerning the use of BQ34Z100-G1 in these conditions?

Thank you in advance and best regards

Matteo

  • Hi Matteo,

    The bq34z100-G1 operates on a per cell basis. Please scale the stack voltage down to ~900 mV for stack voltage detection. With respect to the current sense resistor, please ensure that less than +/- 125 mV is dropped across the sense resistor. With a peak current of 150 A, please use a sense resistance of less than 0.833 mOhms. Please note: current detection will be limited at lower current levels as the the input offset is ~ 10 uV.

    If using the EVM for prototyping, please be aware that the board only supports up to 7A. An external voltage division and current sense circuit would need to be connected, replacing the EVM's respective circuitry via blue wires.

    For configuring parameters to prevent buffer overflow, please follow the steps in SLUA760 for voltage, current and capacity scaling.

    Please let me know how your project turns out!

    Sincerely,
    Bryan Kahler