Patent ID: 7071653

Claim:
A method for charging a non-aqueous electrolyte secondary battery, said secondary battery comprising a positive electrode that comprises a lithium-containing composite oxide as an active material, a negative electrode that comprises a material capable of absorbing and desorbing lithium ion as an active material, and a non-aqueous electrolyte, said method comprising the steps of: (a) detecting an open-circuit-voltage of said secondary battery to determine which of voltage regions A, B and C the detected value is included in, said region A being not smaller than a prescribed value X, said region B being smaller than said prescribed value X and larger than a prescribed value Y (Y<X), and said region C being not larger than said prescribed value Y; and (b) according to said determination, [i] stopping charging when said detected value is included in said region A, [ii] conducting charging when said detected value is included in said region B, or [iii] conducting discharging until a closed-circuit-voltage of said secondary battery becomes not larger than a prescribed value Z and then conducting charging, when said detected value is included in said region C.