Abstract: The amount of charge passing through a measurement resistor connected to a rechargeable battery is measured by integrating in an analog manner an overall current. This overall current is equal to the sum of the resistor current and of a reference current that selectively takes one of two opposite values. The results of the integration are compared with a reference voltage, and one of two opposite values of the reference current is selected depending on each result of the comparison. The number of times where the positive opposite value of the reference current is selected furnishes an indication on the amount of charge during the integration time.