主权项 |
1. A battery state detection device detecting a state of a secondary battery, comprising:
an impedance detection unit detecting a plurality of internal impedances corresponding to a plurality of discrete frequencies in the secondary battery; and a battery state detection unit detecting the state of the secondary battery based on the plurality of internal impedances detected by the impedance detection unit, wherein the plurality of frequencies are allocated to at least two or more out of a plurality of partial frequency ranges respectively corresponding to a plurality of partial graphs showing states of a plurality of components of the secondary battery in a graph in which internal complex impedances of the secondary battery in a predetermined frequency range are plotted on a complex plane, wherein the battery state detection unit uses values of the internal impedances, difference values between the plurality of internal impedances, or both of the values after being weighted, for use in detection of the state of the secondary battery. |