For many reasons, especially the hefty legal fees and unfamiliar system, a lawsuit in the United States is the last thing that most Chinese companies want to be involved in.

And when they do go to court, Chinese companies rarely win cases in the United States.

So when the Chinese Battery Industry Association (BIA) announced last week that its seven major members had won a five-year legal battle against U.S.-based Energizer and its subsidiary Eveready, it made headlines in the Chinese media.

The verdict is seen as a victory not only for battery makers but also many other industries, since Chinese companies have been the most frequent targets of a U.S. trade complaint procedure that can result in a blanket ban on Chinese exports of a particular product to the United States.

Patent or common knowledge?

Wang Jingzhong, the BIA's deputy secretary general, told reporters in Shanghai that the U.S. Court of Appeals for the Federal Circuit had on April 22 finally rejected an appeal on battery patents by Energizer, the second-largest battery maker in the United States.

Five years ago, citing Section 337 of the U.S. 1930 Tariff Act, Energizer filed a complaint with the Washington-based U.S. International Trade Commission (ITC), a quasi-judicial agency whose role is to determine import injury to American industries.

In its complaint, Energizer asked the ITC to issue a cease-and-desist order and bar 28 foreign companies from exporting and selling household-size mercury-free alkaline batteries in the United States, claiming that batteries from China and several other countries had infringed on its mercury-free alkaline battery patent.

Of the 28 companies cited by Energizer, seven are from Chinese mainland, including Fujian Nanping Nanfu Battery Co. Ltd., Zhongyin (Ningbo) Battery Co. Ltd., Guangzhou Tiger Head Battery Group Co. Ltd., and Sichuan Changhong Electric Co. Ltd.

Under Section 337, imported goods can't be sold in the United States if they have been determined to be violating American patent rights. This provision has affected many companies in developing countries that hope to export products to the United States.

The lawsuit caught the seven Chinese companies by surprise.

Wang Jianhao, general manager of Zhongyin, dismissed Energizer's claim.

"We had the technology to produce mercury-free alkaline batteries back in 1993," he said.

"The Hong Kong-based Jinshan Group, which owns my company, was able to produce alkaline batteries three years before Energizer had begun to apply for patents," Wang told Xinhua.

The mercury-free compound for the batteries is like wheels for a car, and everyone knows that a car needs four wheels, said Wang.

"We saw this technology as common knowledge, rather than an invention belonging to a single company," an unidentified BIA official told the English newspaper China Daily.