Patent ID: 8386199

Claim:
A battery monitoring system comprising: a ground line for coupling to a ground terminal of a battery installed in a vehicle; an input line for coupling to a positive terminal of said battery; a voltage sensor coupled to said input line and said ground line and operative to provide voltage data indicative of an output voltage of said battery, said voltage data including voltage data acquired during a time period from when a starter of said vehicle is energized by said battery and an engine of said vehicle starts and being indicative of an initial drop in said output voltage of said battery; memory operative to store data and code; and a processing unit coupled to said memory and said voltage sensor and responsive to said code being operative to receive said voltage data from said voltage sensor, retrieve voltage data previously provided by said voltage sensor from said memory, said previously provided voltage data being indicative of initial drops in said output voltage of said battery during previous time periods when said starter of said vehicle is energized; compare said voltage data from said voltage sensor to said voltage data previously provided by said voltage sensor, determine whether said voltage data differs from said previously provided voltage data by at least a predetermined amount, and generate a notification signal when said voltage data differs from said previously provided voltage data by at least said predetermined amount; and wherein said processing unit is operative to compare said initial drop in said output voltage of said battery with said initial drops in said output voltage of said battery during said previous time periods.