The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 2015
Filed:
Dec. 10, 2010
Shin-ichi Yuasa, Kyoto, JP;
Shin-ichi Yuasa, Kyoto, JP;
Abstract
During charging of a secondary battery, a rate of voltage change dV/dt is obtained when a voltage V of the secondary battery reaches a predetermined voltage V, a charge current I for charging the secondary battery is detected, and a rate of change dQ/dt in a quantity of charged electricity Q of the secondary battery is calculated on the basis of the result of the detection. Here, the predetermined voltage Vis a voltage higher than a discharge cutoff voltage and lower than a charge cutoff voltage. Thereafter, a ratio X: dQ/dV, of the rate of change dQ/dt in the quantity of charged electricity to the rate of voltage change dV/dt is calculated. The calculated ratio X is compared with a reference value X, and degradation of the secondary battery is determined on the basis of the result of the comparison.