STORAGE BATTERY INTERNAL RESISTANCE MEASUREMENT DEVICE AND METHOD

This application discloses an apparatus and a method for detecting internal resistance of a battery, applied to the field of intelligent vehicles, to reduce an internal resistance detection error. The apparatus includes: a processing circuit (51), a differential amplifier (52), and a charging circuit (53). The battery is connected to a first input end of the differential amplifier (52) and the processing circuit (51). The processing circuit (51) is configured to input a first comparison voltage to a second input end of the differential amplifier (52) and maintain the first comparison voltage, where a voltage value of the first comparison voltage is close to a voltage value of a first detection voltage before the battery is charged. The differential amplifier (52) is configured to output a first output voltage based on the first detection voltage and the first comparison voltage. The processing circuit (51) is further configured to control the charging circuit (53) to charge the battery by using a constant current, and detect a second detection voltage of the battery after the battery is charged. The differential amplifier (52) is further configured to output a second output voltage based on the second detection voltage and the first comparison voltage. The processing circuit (51) is further configured to determine the internal resistance of the battery based on the constant current, the first output voltage, and the second output voltage.