Tesla, Inc.
DETERMINING BATTERY DC IMPEDANCE

Abstract:

A controller for use in a battery charging system includes processing circuitry configured to perform certain tasks during battery charging operations, and other tasks during operational use of the battery. During a charging operation, the controller receives a measured DC impedance of a propulsion battery measured by a battery data acquisition and monitoring subsystem, obtains a reference DC impedance of a hypothetical battery, and determines an impedance degradation factor of the propulsion battery using the measured DC impedance and the reference DC impedance. During operational use of the propulsion battery, the controller obtains an operational reference impedance of the propulsion battery, determines a real-time effective impedance for the propulsion battery based on the impedance degradation factor and the operational reference impedance, and generates a feed-forward parameter based on the real-time effective impedance.