Patent ID: 7317300
Filing Date: 2008-01-08
Classification: G01R

Abstract:
1. An automotive battery state monitor apparatus comprising: an electric device; an automotive generator driven by an engine; a battery that stores electricity generated by the generator in a vehicle, wherein a terminal voltage of the battery is defined as a pseudo-open circuit voltage (pseudo-OCV) when a charge/discharge current of the battery is within a predetermined small range; means for storing a correlation information that maps the pseudo-OCV to the battery charge rate; and means for calculating a present residual capacity [SOH2] based on a first charge rate [SOC1], a first residual capacity [SOH1] and a second charge rate [SOC2], each of which are prepared in such a way that the first charge rate [SOC1] and the first residual capacity [SOH1] are stored to memory when the engine is stopped, wherein the terminal voltage that is the pseudo-open circuit voltage is periodically checked when the battery charge/discharge current is within the predetermined range while an engine is not running, and the second charge rate [SOC2] is calculated based on the picked up pseudo-OCV.