Patent ID: 7531909

Claim:
An apparatus for controlling a state of charge (SOC) of a battery mounted on a vehicle provided with an internal combustion engine driving a generator mounted on the vehicle, the battery being charged by power from the generator, comprising: a setting unit that sets a target value directed to control of the state of charge of the battery such that the target value is higher as an efficiency of the internal combustion engine depending on the number of rotations of the engine is higher; a determining unit that determines whether or not the vehicle is in a decelerated state; and a controlling unit that controls a state of rotation of the generator so as to enable the generator i) to perform regeneration when it is determined by the determining unit that the vehicle is in the decelerated state and ii) to perform generation to enable the state of charge of the battery to be the target value when it is determined by the determining unit that the vehicle is not in the decelerated state.