Abstract: The battery pack diagnosis method includes a step of obtaining detection data including a current and a temperature of a battery pack, a step of obtaining function data of an open circuit voltage and a resistance which are functions of a charging state of each of the cells, a step of creating a resistance table of each of the cells using the function data and the detection data, a step of calculating the charging state of each of the cells using the current, the temperature, and the voltage of each of the cells, a step of calculating a charge capacity of each of the cells, the resistance, and a charging state per cell, and a step of calculating an energy capacity of the battery pack using the charge capacity, the charging state per cell, and the resistance.

Abstract: An object is to appropriately estimate capacity deterioration of a storage battery. To this end, a capacity deterioration estimation device includes a data receiver configured to receive measurement results of a current value and a voltage value of a storage battery from a measuring part configured to measure the current value and the voltage value; and a first capacity deterioration estimator, and the first capacity deterioration estimator reads first to fourth tables from a table storage and calculates a first estimated capacity deterioration rate based on first to fourth relational expressions.