Patent ID: 7116078

Claim:
A protection system of a battery of a vehicle, the vehicle having a motor, an ignition system (MA) of the motor, a battery (BA) used by the ignition system (MA) in order to start the motor, an alternator (AL) actuated by the motor in order to recharge the battery (BA) and at least one electric load (CS) supplied by the battery (BA), the protection system comprising a device ( 1 ) for electrically disconnecting or connecting the battery (BA) with respect to the electric load (CS), the device ( 1 ) having switch means ( 20 , 21 , 22 ) connected in series between the battery (BA) and the electric load (CS) and capable of assuming a closed condition and an open condition, the switch means comprising a movable contact ( 21 ) and actuation means ( 20 , 22 ) which can be actuated in order to displace the movable contact ( 21 ), a microprocessor control circuit ( 15 ), comprising means for measuring at least one electrical quantity (V_BATT, VB_AVG) being representative of a state of charge of the battery (BA), comparator means for operating a comparison between a measured value of the electrical quantity (V_BATT, VB_AVG) and a respective threshold value (VTH), control means capable of controlling the actuation means ( 20 , 22 ) as a function of the comparison performed by the comparator means, characterized in that the control circuit ( 15 ) further comprises means for detecting ambient temperature (TEMP), means for detecting time of inactivity of the motor (E_OFF), means for calculating a mean value of voltage (VB_AVG) of the battery, the electrical quantity (V_BATT, VB_AVG) is the mean value of voltage of the battery (BA), the threshold value (VTH) is variable in function of the ambient temperature (TEMP) and the time of inactivity of the motor (E_OFF), the actuation means comprise a bistable electromagnetic arrangement ( 20 , 21 , 22 ) capable of passing from a first stable condition to a second stable condition following a pulse generated by the control means.