ESTIMATION DEVICE, ESTIMATION METHOD, AND COMPUTER PROGRAM

An estimation device includes: a derivation unit () configured to derive a derivation history based on a current, a voltage of a lead-acid battery and a temperature of the lead-acid battery; a specifying unit () configured to specify one or more physical quantities based on the derivation history, and one or more relationships selected from a first relationship between a first history and an amount of positive active material, a second relationship between a second history and a specific surface area of a positive electrode material, a third relationship between a third history and bulk density of the positive active material, a fourth relationship between a fourth history and positive active material particles in a cluster size, a fifth relationship between a fifth history and a cumulative amount of lead sulfate of a negative electrode material, a sixth relationship between a sixth history and a specific surface area of the negative electrode material, a seventh relationship between a seventh history and a corrosion amount of a positive electrode grid, an eighth relationship between an eighth history and resistivity of a positive electrode plate, and a ninth relationship between a ninth history and resistivity of a negative electrode plate; and an estimation unit () configured to estimate a degree of deterioration of the lead-acid battery.