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:
Nov. 22, 1994
Filed:
Jan. 19, 1993
Stephen D Rose, Irvine, KY (US);
Joseph A Cates, Lexington, KY (US);
Jeffrey A Rose, La Jolla, CA (US);
Premier Engineered Products, Inc., Winchester, KY (US);
Abstract
A method and apparatus is provided to charge a battery including a DC charge current supply having a variable output. The charging current is varied in accordance with several sensed parameters in the circuit so that battery voltage is accurately controlled. Initially, constant charging current is applied, and upon detecting that battery voltage increases to the gassing voltage, an incremental step reduction in charging current is triggered. The step reduction causes a decrease in battery voltage, dropping it below the gassing voltage. The step reduced charging current is then applied to increase battery voltage back up to the gassing voltage, thereby triggering another step reduction in charging current. This process is repeated multiple times providing a stepped current profile, i.e., each battery voltage increase to the gassing voltage triggering a step reduction in charging current, and in turn a corresponding voltage reduction. The battery voltage, with the alternating increases and decreases, is thus defined by a saw-tooth profile with peaks at the gassing voltage. When the charging current is finally reduced to a minimum level, the sensed battery voltage triggers a termination of the stepped current reduction. Upon the battery reaching full charge, the application of charging current is terminated.