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:
Feb. 11, 1997
Filed:
Apr. 28, 1995
Jose M Fernandez, Lawrenceville, GA (US);
Vernon Meadows, Lilburn, GA (US);
Erika D Mack, Duluth, GA (US);
Iilonga P Thandiwe, Atlanta, GA (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A battery pack (62) comprises cells (74), and is charged by a charger (64) providing a current level. The charger (64) is a typical nickel-cadmium battery charger providing a first charge current level in excess of an optimum charge current level. The battery pack (62) further comprises a thermal sensing element (76) and an overcurrent charge protection circuit having an overcurrent switch (78), current sense circuit (80), comparator circuit (82), and temperature signal switch (84). If the current level through the cells (74) exceeds the optimum charge current level, the current sense circuit (80) provides a signal to comparator circuit (82) which actuates the temperature signal switch (84), simulating a hot battery pack. The charger (64) then switches to a second charge current level which does not exceed the optimum charge current level. If the charger (64) does not change current levels, a switch delay (86), after a brief period, accumulates enough voltage to actuate a driver switch (88) which opens the overcurrent switch (78), disconnecting the cells (74) from the charger (64).