BATTERY CHARGING AND DISCHARGING CONTROL APPARATUS

摘要

Provided is a battery charging and discharging control apparatus used in a vehicle in which an electric motor can be driven by a battery. The temperature of the battery is detected, a distribution of historical temperatures of the battery for a period after the start of the temperature detection is calculated, and a lifetime work volume of the battery is calculated based on this distribution of historical temperatures of the battery. Based on the lifetime work volume of the battery and on the mileage of the vehicle, an allowable value for a work volume increase rate, which indicates a work volume increase per unit distance, is calculated. Then, a comparison is made between an actual work volume increase rate, which is an actual value for the work volume increase rate of the battery, and the allowable value for the work volume increase rate. If the actual work volume increase rate is larger than the allowable value for the work volume increase rate, the output of the battery is limited to a level further lower by a limiting value than a level to which the output of the battery has already been limited as necessary in a normal travelling state, the limiting value being based on a difference between the actual work volume increase rate and the allowable value for the work volume increase rate. As a result, it is made possible to more accurately perform battery lifetime extension control carried out by setting appropriate charging and discharging allowable values corresponding to past changes of the battery temperature.