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. 19, 2003
Filed:
Feb. 22, 2002
Fujitsu Limited, Kawasaki, JP;
Abstract
The device for charging a secondary battery, comprises: a measuring circuit for measuring the terminal voltage of the battery; a control circuit for controlling a charging current fed through the battery; and an abnormality determining portion which starts a preliminary charging of the battery (S ), finishes the charging (S ) when the voltage of the battery has reached a first threshold value which is decided based on the normal-state upper limit of the internal resistance and the current of the battery (S ), measures the open-circuit voltage of the battery after finishing the charging, determines that the battery is abnormal when the open-circuit voltage is less than a second threshold value (S ), determines that the battery is abnormal when the open-circuit voltage is larger than a third threshold value for detecting that the battery is abnormal (S ), and indicates that the battery is abnormal (S ).