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:
Dec. 07, 1993
Filed:
May. 04, 1992
Pradeep M Bhagwat, Baltimore, MD (US);
Daniele C Brotto, Baltimore, MD (US);
Richard T Walter, Baldwin, MD (US);
Black & Decker Inc., Newark, DE (US);
Abstract
This invention discloses a method and apparatus for rapidly charging a battery by monitoring the voltage of the battery and changing the effective sampling rate of the battery voltage during the charging sequence. More particularly, a first disclosed embodiment of the battery charging system takes voltage readings of the battery as it is being charged at a predetermined rate and stores the voltage values in a first-in, first-out stack in the order in which they are taken. Therefore, a stack of consecutive data samples spaced in time is created. During an interval in the charging sequence where the rate of increase in battery voltage is relatively low, the charging system retrieves voltage values from the stack which are widely separated in time to calculate a slope of the charging profile to determine the status of the charging sequence. During a second interval of the charging sequence when the rate of increase in battery voltage is relatively high, the effective sampling rate is reduced by taking sample points from the stack which are closer together in time. In this manner, the effective sampling rate of the charging system is changed to improve the effective signal-to-noise ratio of the system during the first interval while maintaining an appropriately fast response time during the second interval. An alternative embodiment is disclosed which changes the rate at which the battery voltage is sampled from the first to the second interval in the charging sequence.