Patent ID: 7768266
Filing Date: 2010-08-03
Classification: G01R

Abstract:
1. An automotive battery monitor apparatus comprising: a battery change detector for detecting that the battery mounted on a vehicle has been changed; a battery real internal resistance calculation unit for detecting, upon receipt of an engine start request and upon detection by the battery change detector that the battery has been changed, the internal resistance of the battery based on the battery discharge state at the time of starting the engine; a battery capacitance calculation unit for calculating the battery capacitance after the battery change based on the internal resistance calculated by the battery real internal resistance calculation unit; a battery charge rate calculation method changing unit for changing the method of calculating the battery charge rate based on the battery capacitance calculated by the battery capacitance calculation unit; and a battery degeneration detector for detecting the degeneration of the battery based on the calculated battery capacitance when the battery change detector determines that the battery has not been changed; wherein the battery real internal resistance calculation unit detects the real internal resistance of the battery by dividing a change of the battery voltage at predetermined time intervals by a change of the battery current at the same predetermined time intervals, the detection occurring after a battery change at the time the engine is started but before the vehicle is driven.