Patent ID: 8258750
Filing Date: 2012-09-04
Classification: H01M,H02J,Y02E

Abstract:
1. A charging circuit that charges a battery from a charging power supply according to a constant current constant voltage charging system, said charging circuit comprising: a charging current setting circuit that sets a charging current for each predetermined current level step by step at a time of constant current charging; a charging voltage measurement circuit that measures a supply voltage from said charging power supply; and a control unit; wherein said control unit performs constant current charging by increasing a charging current for said each predetermined current level step by step at the time of the constant current charging, and when said control unit detects one of a plurality of conditions occurring, said control unit stops the increase of the charging current and continues charging maintaining the predetermined minimum voltage, wherein the plurality of conditions comprises detection of the supply voltage of the power supply being at a level below a charging current maintaining determination level by step by step decrease of the supply voltage of the power supply along with step by step increase of the charging current.