Patent ID: 7602149

Claim:
A state of charge (SOC) compensation method that compensates an SOC of a battery, the SOC compensation method comprising: detecting a first SOC, determining a section of a full range of SOC values in which the detected first SOC is included, wherein the full range SOC values is divided into at least two sections, and calculating a first open circuit voltage (OCV) corresponding to the first SOC; measuring a pack current and a pack voltage of the battery, calculating a second OCV by using the pack current, the pack voltage, and an internal resistance, and calculating a second SOC corresponding to the second OCV; comparing the first OCV and the second OCV, and, when a difference between the first OCV and the second OCV is greater than a first reference value, compensating the first SOC using a first compensation value determined according to the section in which the first SOC is included, and when the difference between the first OCV and the second OCV is less than a second reference value, compensating the first SOC using a second compensation value determined according to the section in which the first SOC is included; and controlling a charging and discharging of the battery according to the compensated SOC.