Patent ID: 7971345

Claim:
A method of producing a reconstituted battery pack, comprising: obtaining a reference-time charge amount charged in each of used secondary batteries constituting a used battery pack when a representative state of charge of the used battery pack is controlled to a predetermined reference value with use of a charged-state control device programmed to calculate the representative SOC estimated to be representative of SOCs of used secondary batteries constituting the used battery pack, and programmed to control a charged state of the used battery pack so that the representative SOC becomes the predetermined reference value, the charged-state control device being one of a first charged-state control device having ever controlled the charged state of a used battery pack when this used battery pack was used before, and a second charged-state control device programmed to control the charged state of the used battery pack as with the first charged-state control device; selecting more than one of the used secondary batteries close to each other in the reference-time charge amount from a group of the used secondary batteries used in one or more of the used battery packs, the reference-time charge amount of each used secondary battery having been obtained; and combining and assembling the selected used secondary batteries into a new reconstituted battery pack, wherein the selecting includes selecting the used secondary batteries so that a difference in the reference-time charge amount between a largest one and a smallest one of the reference-time charge amounts of the selected used secondary batteries falls within 30% of the smallest reference-time charge amount.