Battery power monitoring apparatus for vehicle

摘要

A battery power monitoring apparatus for use in an electric automobile is provided. The battery power monitoring apparatus determines the amount of available reserve electric power remaining in a storage battery based on electric power discharged from the storage battery to an electric motor and a battery characteristic stored in a memory, representing a relation between a voltage level at which a given level of current flows from the storage battery and the then discharged electric power. The battery characteristic is updated based on the latest detected voltage of the storage battery and current flowing from the storage battery. The battery power monitoring apparatus determines that charge polarization has occurred when a voltage level of the storage battery from which the given level of current flows is increased, and prohibits the updating of the battery characteristic. With this operation, the amount of available electric power is calculated correctly even under the influence of charge polarization.