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:
Nov. 09, 2004
Filed:
Jan. 24, 2002
George D. Goodman, Phoenixville, PA (US);
Alliburton Energy Services, Inc., Houston, TX (US);
Abstract
A protection circuit couples to and protects a battery cell. The protection circuit generally limits the current that can flow through cell when the voltage across the cell falls to a predetermined minimum threshold, such as might occur if the cell is passivated, fails in service, or is reaching the end of its useful life. The protection circuit preferably includes a transistor, which couples in series with the cell and limits the current therethrough. By limiting the current through the cell when its voltage reaches a minimum threshold, the voltage on the cell will not fall below the minimum safe level. A bypass means (e.g., a diode) also is included to conduct current around the cell when its current has been limited by the transistor.