Duracell batteries. Photo: Reuters.

INTERNATIONAL - The maker of Energizer batteries sued the maker of Duracell batteries on Monday, accusing Duracell of duping consumers by implying that its new “Optimum” AA and AAA batteries are more powerful and last longer than all rival batteries.

Energizer said Duracell, a unit of Warren Buffett’s Berkshire Hathaway, engaged in false advertising for Optimum with packaging that said its batteries offer “extra life” and “extra power,” and TV commercials that said: “Both is better than not both.”

It is only in the “mice-type” fine print, according to Energizer, that battery buyers learn that Optimum may outperform Duracell’s own Coppertop batteries, not rival batteries, and only in some devices.

“These paltry and sporadic benefits are not the stuff great ads are made of and, indeed, barely seem worth touting at all,” Energizer said in its complaint in Manhattan federal court.

The St. Louis-based company is seeking damages for false advertising under New York law and the federal Lanham Act, and a halt to any improper advertising.

Duracell did not immediately respond to requests for comment.

Berkshire bought Duracell, which has offices in Chicago and Bethel, Connecticut, from Procter & Gamble in February 2016. It was not named specifically as a defendant.

The lawsuit is not the first Duracell has faced over Optimum, which were launched in July.

In August, New Jersey vaping company What A Smoke LLC accused Duracell of infringing its trademark rights in “Optimum” with respect to batteries, battery chargers, liquids and other products associated with electronic cigarettes. That lawsuit was filed in the federal court in Newark, New Jersey.