METHOD FOR DETERMINING COMPLETION OF CHARGE OF LITHIUM ION SECONDARY BATTERY, METHOD FOR DETERMINING TERMINATION OF DISCHARGE OF LITHIUM ION SECONDARY BATTERY, CHARGE CONTROL CIRCUIT, DISCHARGE CONTROL CIRCUIT, AND POWER SUPPLY

摘要

A method for determining completion of charge of a long-duration lithium ion secondary battery is provided.;A method for determining completion of charge a lithium ion secondary battery including one lithium compound having an olivine crystal structure as a positive electrode active material, and a graphite material as a negative electrode active material, includes: (S1) charging the battery by an amount of electricity Xc in time Ti1; (S2) stopping the charging for time Yc after completion of (S1), and measuring a battery voltage Vi1 after the time Yc has passed; (S3) charging the amount of electricity Xc in the time Ti1 after completion of (S2); (S4) stopping the charging for the time Yc after completion of (S3), and measuring a battery voltage Vi2 after the time Yc has passed; and comparing Vi2−Vi1 with a predetermined voltage difference Vi3 to determine that the charge has been completed when Vi2−Vi1Vi3, and determine that the charge has not been completed when Vi2−Vi1Vi3.