Patent ID: 7728555

Claim:
A driving method for a battery management system connected to an engine control unit of a vehicle using electrical energy, the driving method comprising: a) measuring a charge and discharge current of a battery and a battery voltage; b) calculating a first state of charge and a first voltage corresponding to the first state of charge using the charge and discharge current of the battery; c) calculating a rheobasic voltage of the battery using the charge and discharge current of the battery, the battery voltage, and an internal resistance of the battery; d) calculating an integration error corresponding to a difference between the first voltage and the rheobasic voltage; e) determining whether the integration error is within a predetermined effective range; f) when the integration error falls outside the predetermined effective range, compensating the state of charge by subtracting a first state of charge compensation factor to the first state of charge when the integration error is above the predetermined effective range, and by adding a second state of charge compensation factor different from the first state of charge compensation factor to the first state of charge when the integration error is below the predetermined effective range, to obtain a compensated state of charge so that the compensated state of charge is within a state of charge range corresponding to the predetermined effective range; and g) outputting the compensated state of charge to the engine control unit as a present state of charge of the battery.