Method of estimating battery life, battery life estimation device, electric vehicle, and electric power supply apparatus

A method of estimating a battery life, the method comprising:

• identifying a degradation master data by using conditions of temperature T and a battery state S,
• deriving number of elapsed days Xcorr corresponding to a degradation rate R based on the degradation master data,
• calculating a degradation estimation value (Xcorr+Y) days after the initial charge based on the degradation master data,
• wherein the conditions during Y days are configured of n-number of conditions Z1, Z2, . . . , Zn where 1≦n, and
• making transition from first degradation master data identified by the condition Zn−1 to second degradation master data identified by the condition Zn, so as that a final degradation rate in the first degradation master data is equal to a start degradation rate in the second degradation master data.