US Patent 9406982 Secondary battery reuse method, vehicle drive power source, and vehicle

Secondary battery reuse method in which, when used secondary battery packs G and A in a lithium secondary battery have become unusable, the resistances and capacities of a plurality of secondary battery stacks constituting the secondary battery pack G are measured and a reusable secondary battery stack is selected and separated therefrom by comparing these measured resistances and capacities with a resistance threshold value H and a capacity threshold value I, respectively. In addition, a new secondary battery pack is rebuilt (constructed) by combining the secondary battery stack with a secondary battery stack that has been determined to be reusable in the secondary battery pack A in the same manner as in the secondary battery pack G.