MADISON, Wis. (AP) _ Rayovac has lost its patent infringement lawsuit accusing Duracell of taking technology that makes batteries last longer.

The Madison-based Rayovac Corp. said in a news release Wednesday it plans to investigate options for possible further judicial review of the decision handed down by a jury in U.S. District Court in Madison.

The jury found three of Rayovac's zinc air hearing aid patents were invalid.

``Rayovac still holds more patents than the combined total of all our competitors,'' said Dave Jones, Rayovac chairman and chief executive officer.

Rayovac had claimed in the suit filed in April 1999 that Duracell Inc., of Bethel, Conn., infringed on its 1995 and 1996 patents for the high energy density metal-air cell and its thin-walled electrochemical cell.

Those cells, which are thinner than previous cells, make for longer-lasting batteries.

Duracell, a division of Boston-based Gillette Co., issued a statement saying the company had proved to the jury that its recent innovations in zinc air hearing aid batteries were legally sound because the Rayovac patents were invalid.