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:
Sep. 08, 2015
Filed:
Dec. 12, 2012
GM Global Technology Operations Llc, Detroit, MI (US);
Christopher W. Mousseau, Canton, MI (US);
Michael Wahlstrom, Walled Lake, MI (US);
Zachary D. Bylsma, Rochester Hills, MI (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
A method for estimating charge capacity of a lithium iron-phosphate battery pack using data from a plug-in charge event. A laboratory-measured battery pack resistance, which is known to remain constant over a battery pack's life, can be used to determine open circuit voltage from terminal voltage during charging. Actual open circuit voltage after charging can be measured later, after the battery pack has rested for a sufficient amount of time. The two values of open circuit voltage, if taken at points on the battery pack's SOC-OCV curve which have great enough slope, provide two values of battery pack state of charge. By integrating charging current over the time interval between the two open circuit voltage readings, and using the two state of charge values, the battery pack capacity can be determined from the plug-in charge data.