BATTERY SYSTEM FOR HYBRID CAR AND HYBRID CAR EQUIPPED WITH THIS BATTERY SYSTEM

摘要

[Problem] To prevent the lifetime of a battery for traveling from being shortened in an extremely-low temperature while enabling the travel of a vehicle in an excessively discharged state of a battery for in-vehicle electric devices by charging the battery for in-vehicle electric devices using the battery for traveling. [Solution] A battery system for a hybrid car comprises: a battery (1) for traveling that supplies power to a motor (11) for allowing a vehicle to travel; a DC/DC converter (3) that steps down the voltage of the battery (1) for traveling; a battery (2) for in-vehicle electric devices that is charged by the voltage stepped down by the DC/DC converter (3); a control circuit (4) that controls charging to the battery (2) for in-vehicle electric devices by the battery (1) for traveling; and a temperature sensor (5) that detects the temperature of the battery (1) for traveling or ambient temperature. The control circuit (4) controls the charging current for charging the battery (2) for in-vehicle electric devices by the battery (1) for traveling such that the charging current when the temperature detected by the temperature sensor (5) is lower than a set temperature is smaller than the charging current when the temperature detected by the temperature sensor (5) is higher than the set temperature.