A charge circuit composed of a first circuit (la) and a second circuit (lb), said second circuit being provided at a battery pack in which a secondary battery is comprised, said first circuit being provided at a charger for charging said secondary battery in said battery pack, wherein said charge circuit comprises: - an output power supply section (21, 23) which is included in said first circuit and configured to output an electric power to said secondary battery; - a control section (3, 33, 45) which is configured to control said output power supply section (21, 23) to perform a charging operation, wherein said control section (3, 33, 45) is configured to, in said charging operation, perform first a constant current charging operation, perform a constant voltage charging operation after finishing the constant current charging operation, and finish the charging operation when a charging current reaches a charge stop current value, wherein said control section or a part of said control section (33, 45) is included in said first circuit; - a memory which stores a number of charging defined as the number of times of performing said charging operation, said memory being provided at said second circuit in said battery pack; and - a threshold current setting section configured to determine said charge stop current value, and wherein said threshold current setting section is configured to decrease said charge stop current value along with the increase of said number of charging, characterized in that said memory is configured to store a data table including a relationship between said number of charging of said secondary battery and said charge stop current value, wherein said threshold current setting section is configured to read said data table and said number of charging from said memory and to determine said charge stop current value according to said number of charging. - an output power supply section (21, 23) which is included in said first circuit and configured to output an electric power to said secondary battery; - a control section (3, 33, 45) which is configured to control said output power supply section (21, 23) to perform a charging operation, wherein said control section (3, 33, 45) is configured to, in said charging operation, perform first a constant current charging operation, perform a constant voltage charging operation after finishing the constant current charging operation, and finish the charging operation when a charging current reaches a charge stop current value, wherein said control section or a part of said control section (33, 45) is included in said first circuit; - a memory which stores a number of charging defined as the number of times of performing said charging operation, said memory being provided at said second circuit in said battery pack; and - a threshold current setting section configured to determine said charge stop current value, and wherein said threshold current setting section is configured to decrease said charge stop current value along with the increase of said number of charging, characterized in that said memory is configured to store a data table including a relationship between said number of charging of said secondary battery and said charge stop current value, wherein said threshold current setting section is configured to read said data table and said number of charging from said memory and to determine said charge stop current value according to said number of charging.