Elon Musk_Tesla
Elon Musk, CEO of Tesla Motors, waves during a recent news conference. Reuters

Electric carmaker Tesla Motors Inc. (Nasdaq: TSLA) will decide where to build a battery “gigafactory” before the end of the year, CEO Elon Musk told investors Tuesday at an annual shareholder meeting.

The company proposed the huge battery plant in February to produce lower-cost lithium-ion cells for its cars and storage devices for home power.

Although it will ultimately build the factory in one location, Tesla will begin preparations for the factory soon in as many as three states, where it will create a foundation, finish plans and gain local approval for “gigafactory 1 before the end of the year,” Musk said at the meeting in Mountain View, California. Plans for the plant are “quite advanced,” with daily discussions with Tesla’s main battery cell supplier Panasonic Corp. about the project, Musk added.

The plant will eventually cost as much as $5 billion to build and employ up to 6,500 people, the company has said. Tesla has been studying sites in Texas, New Mexico, Arizona and Nevada, and Musk added California to that list last month.

The gigafactory should cut lithium-ion cell costs by at least 30 percent, according to Tesla, which would help the company reach its goal of producing a mass market for electric cars in three years.