| 主权项 |
1. An internal resistance estimation method for a secondary battery, the secondary battery including a positive electrode and a negative electrode, the internal resistance estimation method comprising:
acquiring an initial internal resistance value of the secondary battery and temperature course information, the secondary battery being an evaluation object, the temperature course information including a battery temperature of the secondary battery in use and time information about time at which the battery temperature has been recorded, and the initial internal resistance value being an internal resistance value of the secondary battery at predetermined reference time; estimating an increased amount of the internal resistance value of the secondary battery after a lapse of a predetermined time from the predetermined reference time, on the basis of the temperature course information; estimating a reduced amount of the internal resistance value of the secondary battery resulting from a relative change between a range of use of a state of charge of the positive electrode and a range of use of a state of charge of the negative electrode, in the lapse of the predetermined time from the predetermined reference time, on the basis of the temperature course information; calculating an internal resistance variation in the lapse of the predetermined time from the predetermined reference time, on the basis of the increased amount and the reduced amount; and obtaining an estimated internal resistance value of the secondary battery after the lapse of the predetermined time from the predetermined reference time, on the basis of the initial internal resistance value and the internal resistance variation. |
