A device for charging a battery, or a battery of an electric traction automotive vehicle, based on a three-phase or single-phase power supply network, including a filtering stage including a capacitive assembly and configured to be connected to the power supply network. The device includes a mechanism to monitor capacitive assembly and to detect a deviation in value of the capacitance of at least one capacitor of the capacitive assembly on the basis of voltages and currents measured across the input terminals of the filtering stage.