Patent ID: 6791464
Filing Date: 2004-09-14
Classification: G01R

Abstract:
In an apparatus provided in a motor vehicle, the apparatus comprising:a monitor and alarm device directly parallel connected to both a battery to be measured and a starting motor of the motor vehicle; wherein the starting motor is taken as a load for forming an outer loop sampling circuit, 1/t second is set as a sampling time interval during discharging, voltage curve is formed by connecting a plurality of continuous sampled voltage values each sampled in 1/t second, wherein the battery to be measured begins from a point P1 to a point P2 where an engine of the motor vehicle is beginning to start, then the voltage measured at battery terminals is significantly and temporarily dropped down and formed a lowest point P3 of the voltage curve during the engine starting at a very beginning period, thus a minimum voltage value is obtained, in a subsequent section, a plurality of points P4 of ripples voltage values are continuously formed to represent that the engine has been started for a very short time period, and a final point P5 represents a charging point of an alternator, and a minimum voltage value from any point of points P2 to P4 of the voltage curve is compared with a predetermined alarm voltage value for determining a status of the battery to be measured, and an alarm is issued in time if the status of the battery to be measured is abnormal.