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:
Jun. 25, 1991
Filed:
Jan. 27, 1989
Saifee Fakruddin, St. Joseph, MI (US);
Mark J Foster, Stevensville, MI (US);
Zenith Data Systems Corporation, Mt. Prospect, IL (US);
Abstract
A method and apparatus for monitoring the voltage discharge of a battery power supply while under load, and to manage the power supply by accurately calculating the time the useful charge is nearly depleted, providing a series of warnings to the user-operator of that fact, and subsequently performing a system shutdown before a complete discharge of the battery. If the invention is applied to a battery power supply for a computer, the series of warnings enable the computer operator to transfer data from a temporary memory to permanent storage in the time interval between a warning signal and computer shutdown; and since computer shutdown is effected before the battery is fully discharged a battery-destructive phenomenon known as a polarity cell reversal is prevented. The battey monitoring and management techniques disclosed comprise generating periodically at a first rate a voltage-discharge value (SS) indicative of the rate of change of battery discharge voltage with respect to the elapse of time while the battery power supply is under load, generating periodically at the first rate a compensation-factor value (CF) which is numerically larger in absolute value than the absolute value of SS during at least the initial portion of the startup voltage depression and which is thereafter periodically decremented at a second rate until CF reaches a predetermined fixed value (FCF) approaching the SS of the stable section of the voltage discharge curve, and generating periodically at the first rate a real-time compensated voltage-discharge value (CSAV) in accordance with the functional expression: ##EQU1## The real-time CSAV(s) determine the particular battery management step taken.