Abstract: A refresh control system that selectively initiates a refresh charge cycle includes an energy storage device and an electric machine that is operable to charge the energy storage device. A control module monitors a usage period of the energy storage device and determines a bias factor. The control module determines a modified usage period threshold based on a usage period threshold and the bias factor. The control module regulates the electric machine to initiate a refresh charge cycle of the energy storage device when the usage period exceeds the modified usage period threshold.
Type:
Grant
Filed:
February 9, 2005
Date of Patent:
August 4, 2009
Assignee:
GM Global Technology Operations, Inc.
Inventors:
Andrew M. Zettel, Damon R. Frisch, Mary A. Jeffers, Goro Tamai, Brian J. Koch