A circuit breaker comprising a monitoring device of an electric power supply comprising: - a series of first terminals designed to be connected to a primary power supply for supplying the monitoring device, the power supply monitored by the monitoring device forming the primary power supply, - a battery connected to supply the monitoring device as secondary power supply, in case of outage of the primary power supply, - measuring means configured to measure the voltage (V bat) at terminals of the battery, - a management circuit to detect a malfunctioning of the battery, characterized in that it comprises - a storage circuit configured to record indicators linked to the causes of tripping of the circuit breaker and supplied by the battery in case of outage of the primary power supply, - a comparator configured to compare the voltage measured by the measuring means with first and second threshold values (V min, V OFF) representing respectively a non-recoverable battery and a functional battery, an output of the comparator being coupled to the management circuit, - a switch configured to disable/enable flow of a discharge current (I d) at the terminals of the battery, - a counter configured to count a quantity representative of the discharge current (I d), an output of the counter being coupled to the management circuit, in that the measuring means are configured to measure the voltage (V bat) at terminals of the battery when the monitoring device is supplied by the primary power supply and the management circuit is configured to detect a failure of the battery when the monitoring device is supplied by the primary power supply and to control the state of the switch according to the comparison of the measured voltage (V bat) with the first and second threshold values (V min, V OFF) and according to the value of the counter and in that the management circuit is configured to apply a discharge current (I d) to the terminals of the battery if the measured voltage (V bat) is comprised between the first and second threshold values (V OFF, Vmin). - a series of first terminals designed to be connected to a primary power supply for supplying the monitoring device, the power supply monitored by the monitoring device forming the primary power supply, - a battery connected to supply the monitoring device as secondary power supply, in case of outage of the primary power supply, - measuring means configured to measure the voltage (V bat) at terminals of the battery, - a management circuit to detect a malfunctioning of the battery, - a storage circuit configured to record indicators linked to the causes of tripping of the circuit breaker and supplied by the battery in case of outage of the primary power supply, - a comparator configured to compare the voltage measured by the measuring means with first and second threshold values (V min, V OFF) representing respectively a non-recoverable battery and a functional battery, an output of the comparator being coupled to the management circuit, - a switch configured to disable/enable flow of a discharge current (I d) at the terminals of the battery, - a counter configured to count a quantity representative of the discharge current (I d), an output of the counter being coupled to the management circuit,