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. 09, 1999
Filed:
Jun. 22, 1998
Mark J Mercer, Tucson, AZ (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A battery charger monitors the terminal voltage of a secondary battery connected thereto with no appreciable depletion of the battery energy. Upon the completion of the charge cycle, the battery charger monitors the terminal voltage of the battery by first creating a high impedance node at the battery low side, and then regulating the battery high side voltage to a value below the maximum allowable terminal voltage for the battery. The battery low side voltage will decreases in response to a value below ground. The charger monitors the terminal voltage across the battery by measuring the battery low side voltage When the battery charger detects that the battery has discharged to a predetermined capacity level, the charger initiates a charge maintenance mode. The battery charger either refreshes the battery or maintains the battery at the predetermined capacity level.