Electric car maker Tesla Motors has a battery problem. It doesn't have enough of them.

That's one reason the high-flying company's shares fell 14.5 percent Wednesday, their sharpest drop in almost two years.

CEO Elon Musk on Tuesday blamed a shortage of lithium-ion battery cells for trouble meeting demand for Tesla's lone vehicle, the Model S. Some cars that could have been sold in North America were diverted to Europe to satisfy waiting customers, Musk said on a conference call after Tesla released third-quarter earnings.

There won't be any relief until next year, when a deal to get more batteries from supplier Panasonic kicks in, he said.

Shares of the Palo Alto, Calif., company dropped $25.65 to $151.16.