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:
Aug. 28, 2018
Filed:
Dec. 01, 2014
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
Akihide Tanaka, Tokyo, JP;
Yohshin Yagi, Hitachinaka, JP;
HITACHI AUTOMOTIVE SYSTEMS, LTD., Ibaraki, JP;
Abstract
A battery module includes a lithium ion secondary battery and a control circuit. The control circuit includes a measurement unit which measures voltage, current, and the time of charge/discharge of the lithium ion secondary battery; an operation unit which calculates a capacity based on the voltage, the current, and the time and calculates a differential value dQ/dV by differentiating the capacity with a voltage; a threshold voltage setting unit which specifies a peak of a low capacity side of the differential value dQ/dV generated on the basis of a stage structure of graphite and sets a voltage at the peak to a threshold voltage; a cutoff voltage setting unit which sets a discharge cutoff voltage of the lithium ion secondary battery on the basis of the threshold voltage; and a charge/discharge control unit which controls charge/discharge of the lithium ion secondary battery on the basis of the discharge cutoff voltage.