Tesla falls on Musk cautioning battery output is years away

Gabrielle Coppola and Dana Hull

Elon Musk tempered expectations for Tesla Inc.’s long-awaited battery day by cautioning that the company will unveil something that won’t be widely produced for two years.

Tesla shares fell as much as 6% and were down 5.2% at $425.97 as of 9:50 a.m. in New York. The pull-back comes after massive gains in recent months fueled in part by anticipation of Tuesday’s event. Musk said the information he’ll announce will affect production of Tesla’s Semi, Cybertruck and Roadster models, all of which have been unveiled in the form of prototypes but are still in development.

Elon Musk

In another tweet, Musk warned of the “extreme difficulty” of scaling up production of new technology. It was the latest in a series of posts that were more measured about the much-hyped event the chief executive officer had previously talked up. The company’s shareholder meeting and subsequent battery briefing get underway starting at 1:30 p.m. local time in California.

Musk said in another tweet that Tesla will need to start producing its own battery cells to support its various products, even as it ramps up purchases from outside suppliers. He wrote that the company expects there to be significant shortages of cells in 2022 and beyond unless it ramps up output of its own.

Tesla’s most important and longstanding partner on batteries is Osaka-based Panasonic Corp. The two companies jointly operate a massive plant outside of Reno, Nevada, where Panasonic makes the cells and Tesla manufactures battery packs for its cars.

But Musk has never been keen about depending on one supplier, and Tesla does have smaller-scale agreements with Contemporary Amperex Technology Co., or CATL, in China’s Fujian province and LG Chem Ltd. in Seoul.