METHOD AND SYSTEM FOR CALIBRATING BATTERY PACK VOLTAGE BASED ON COMMON-MODE CALIBRATION PARAMETER AND DIFFERENTIAL-MODE CALIBRATION PARAMETER

Method, system, and programs for calibrating battery pack voltage are disclosed. A negative terminal voltage of a cell is changed from a first to a second negative terminal voltage so that a cell voltage is changed from a first to a second output voltage. A positive terminal voltage of the cell is maintained at a substantially constant level. A differential-mode calibration parameter is calculated based on a difference between the first and second output voltages and a difference between the first and second negative terminal voltages. The negative terminal voltage of the cell is then changed from the first to second negative terminal voltage so that the positive terminal voltage of the cell is changed from a first to a second positive terminal voltage and the output voltage is changed from a third to a fourth output voltage. The cell voltage is maintained at a substantially constant value. A common-mode calibration parameter is calculated based on the differential-mode calibration parameter and a difference between the third and fourth output voltages and a difference between the first and second positive terminal voltages.