SLUUCH2 March 2021 BQ40Z50-R2
The BQ40Z50-R4 measures individual cell voltages, pack voltage, temperature, and current. It determines battery state-of-charge by analyzing individual cell voltages when a certain relax time has passed since the last charge or discharge activity of the battery.
The BQ40Z50-R4 measures charge and discharge activity by monitoring the voltage across a small-value series sense resistor (1-mΩ typical) between the negative terminal of the cell stack and the negative terminal of the battery pack. The battery state-of-charge is subsequently adjusted during a load or charger application using the integrated charge passed through the battery. The BQ40Z50-R4 device is capable of supporting a maximum battery pack capacity of 32 Ah. See the Theory and Implementation of Impedance Track™ Battery Fuel-Gauging Algorithm in bq20zxx Product Family (SLUA364) for further details.
The default for Impedance Track gauging is off. To enable the gauging function, set Manufacturing Status[GAUGE_EN] = 1. The gauging function will be enabled after a reset or a seal command is set. Alternatively, the Gauging() MAC command can be used to turn on and off the gauging function. The Gauging() command will take effect immediately and the [GAUGE_EN] will be updated accordingly.
The GaugeStatus1(), GaugeStatus2(), and GaugeStatus3() commands return various gauging related information that is useful for problem analysis.