The United States Court of Appeals for the Federal Circuit (CAFC) upheld the decision of the International Trade Commission (ITC) by invalidating US patent 5464709 of the U.S. battery maker Energizer Holdings who sued nine Chinese battery makers.  The decision was final.  The Chinese battery makers coordinated by the China Battery Industry Association ended this five-year legal battle on a triumphant note.
  
On April 28, 2003, Energizer filed for 337 investigation against the nine Chinese companies including Nanfu for infringing its 709 patent. An ITC presiding judge made an initial determination on June 2, 2004, affirming the claim construction of the plaintiff and the validity of the 709 patent while establishing infringement of the Chinese companies. The defendants then petitioned for review by the ITC. On October 2, 2004, ITC made a final determination, ruling the patent invalid on the ground of lack of certainty.  In January 2006, CAFC vacated the ITC determination and remanded the case back to ITC.  In February 2007, ITC determined again that the 709 patent was invalid. Energizer appealed again to the CAFC. On April 22, 2008, CAFC affirmed the ITC determination by invalidating the 709 patent.

(China IP News)