Patent ID: 6472875
Filing Date: 2002-10-29
Classification: G01R

Abstract:
A process for detecting a defect in a battery of an automotive vehicle with an internal combustion engine and an electric starter wired to the battery of the vehicle for cranking the engine during a cranking phase, the process which comprises:cranking an internal combustion engine through consecutive engine cycles with a starter connected to the battery; measuring at least two successive values U1 and U2 of a discharge voltage of the battery during two consecutive engine cycles; calculating a difference &Dgr;U=U1âˆ’U2 between the measured voltage values; determining a state of charge of the battery from the difference &Dgr;U; calculating a moving average of the measured discharge voltages (U1; U2); and deducing that the battery is defective if the first derivative of the average is less than or equal to zero.