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:
Apr. 02, 1996
Filed:
Dec. 15, 1993
Peter R Holloway, Andover, MA (US);
Robert A Mammano, Costa Mesa, CA (US);
Unitrode Corporation, Billerica, MA (US);
Abstract
An adaptive battery charger circuit including a state machine adjusts the charging current in accordance with the battery charge acceptance. The battery charging cycle includes an initial charging phase characterized by a relatively high charge acceptance, an intermediate charging phase characterized by a decreasing charge acceptance and a rising battery temperature, and a final charging phase characterized by the battery being at substantially full charge and the charge acceptance approaching zero. Each charging phase corresponds to one or more states of the state machine. Multiple sets of conditions causing transitions between the states of operation are derived from a model of a battery under charge which relates charge acceptance, battery temperature, and cumulative supplied charge. During the intermediate charging phase, the charging current is adjusted to maintain a predetermined battery temperature for a predetermined duration. With this arrangement, the maximum product of charging current and charge acceptance maintainable for the battery without exceeding a safe temperature is continuously achieved.