Patent ID: 9157963
Filing Date: 2015-10-13
Classification: G01R,Y02E

Abstract:
1. A method for calibrating battery pack voltage, the battery pack having a plurality of cells connected in series, the method comprising: changing a negative terminal voltage of one of the plurality of cells from a first negative terminal voltage to a second negative terminal voltage so that an output voltage indicative of cell voltage is changed from a first output voltage to a second output voltage, wherein a positive terminal voltage of the cell is substantially constant; calculating a voltage difference between the first output voltage and the second output voltage; calculating a differential-mode calibration parameter that is to be used to calibrate the cell voltage, based on the voltage difference between the first output voltage and the second output voltage and a voltage difference between the first negative terminal voltage and the second negative terminal voltage, wherein the differential-mode calibration parameter is equal to the voltage difference between the first output voltage and the second output voltage divided by the voltage difference between the first negative terminal voltage and the second negative terminal voltage; changing the negative terminal voltage of the cell from the first negative terminal voltage to the second negative terminal voltage so that the positive terminal voltage of the cell is changed from a first positive terminal voltage to a second positive terminal voltage and the output voltage indicative of the cell voltage is changed from a third output voltage to a fourth output voltage, wherein the cell voltage is substantially constant; and calculating a common-mode calibration parameter based on the differential-mode calibration parameter and a voltage difference between the third output voltage and the fourth output voltage and a voltage difference between the first positive terminal voltage and the second positive terminal voltage, wherein the differential-mode calibration parameter and common-mode calibration parameter are used to calibrate the cell voltage.