Control circuit for determining a charge current of a battery

摘要

This application relates a method and a control circuit (10) for determining a charge current of a battery (4) connected to a modulated load (2) is proposed, wherein a current limited power source (11) is connected in parallel to the modulated load (2) and the battery (4) for supplying a load dependent current up to a predetermined current limit to the modulated load (2) and the battery (4). The control circuit (10) comprises means (12, 13) for measuring a current flowing through the battery; means (16) for indicating an overload condition of the current limited power source (11); and means (15) for determining the charge current of the battery (4). The means (16) for indicating an overload condition are configured to indicate an overload condition when a sum of a current (3) drawn by the modulated load (2) and a current (5) flowing into the battery exceeds the predetermined current limit of the current limited power source (11), and wherein said means (15) for determining the charge current of the battery (4) are configured to determine the charge current based on measured current values selected from one or more time intervals during which no overload condition is indicated by the means (16) for indicating the overload condition.