Patent ID: 8111035
Filing Date: 2012-02-07
Classification: H02J

Abstract:
1. A charging system, comprising: a secondary battery; a charging current supplier for supplying a charging current to the secondary battery; an internal resistance detector for detecting a resistance value of the internal resistance of the secondary battery; a charge controller for increasing the charging current to be supplied to the secondary battery by the charging current supplier as the resistance value detected by the internal resistance detector decreases; a voltage detector for detecting a terminal voltage of the secondary battery; and a current detector for detecting the current flowing into the secondary battery, wherein the internal resistance detector calculates the resistance value of the internal resistance by dividing a difference between the terminal voltage detected by the voltage detector when the charging current supplier supplies a specified first internal resistance detection current to the secondary battery and the terminal voltage detected by the voltage detector when the charging current supplier supplies a specified second internal resistance detection current different from the first internal resistance detection current by a difference between the first internal resistance detection current and the second internal resistance detection current.