Patent ID: 8914248
Filing Date: 2014-12-16
Classification: G01R

Abstract:
1. A device for estimating internal resistance of a battery, comprising: a first memory unit that stores voltage difference values between sampled voltage values and current difference values between sampled current values for a predetermined period of time; a selection unit that periodically selects a maximum value of the voltage difference values and a maximum value of the current difference values stored in the first memory unit, or selects a minimum value of the voltage difference values and a minimum value of the current difference values stored in the first memory unit; a second memory unit that stores the voltage difference values and the current difference values selected by the selection unit; and a first operation unit that calculates a covariance value of the voltage difference values and the current difference values stored in the second memory unit, and a variance value of the current difference values stored in the second memory unit, and estimates an internal resistance of the battery using the covariance value and the variance values.