Apparatus and method for controlling state of charge/discharge of battery of hybrid car

The temperature of a battery (50) is supervised by temperature sensor (74). When the temperature of the battery is not higher than a predetermined temperature, a battery ECU (68) issues a command to a control CPU (56) to perform forcible charge/discharge of the battery (50) to raise the temperature of the battery. When raising of the temperature is performed by charging, a requested output from the engine (10) is enlarged as compared with a usual state. Thus, motor-generators (26, 28) are operated as generators so as to generate electric power. Thus, electric power is charged to the battery so as to pass an electric current. When raising of the temperature is performed by discharging, the requested output from the engine (10) is reduced as compared with the usual state. Thus, the motors/generator (28) is operated as a motor to consume electric power so as to pass an electric current. The electric current allowed to flow at this time causes internal resistance to be generated in the battery so as to heat the battery from the inside portion thereof. Thus, an apparatus for controlling a charge/discharge state of a hybrid car structured to be capable of quickly and easily controlling the temperature of the battery to a predetermined temperature can be provided.