Patent ID: 7439745
Filing Date: 2008-10-21
Classification: G01R,H01M,Y02E

Abstract:
1. A life determining method of a nickel-hydride battery, comprising the steps of: (a) preparing beforehand data representing a relationship of life of the battery to load power of the battery in discharge and environmental temperature of a place where the battery is installed; (b) measuring the load power and the environmental temperature of the battery in discharge; (c) selecting a life value corresponding to the measured values of the load power and the environmental temperature from the data to set the life value as an expected life value; (d) calculating a first life reduction amount from a natural logarithmic function with the number-of-discharges of the battery as a variable; and (e) setting a value obtained by subtracting the first life reduction amount from the expected life value to a remaining life value.