(Fortune Magazine) -- Warren Buffett is famous for his rules of investing: When a management with a reputation for brilliance tackles a business with a reputation for bad economics, it is usually the reputation of the business that remains intact. You should invest in a business that even a fool can run, because someday a fool will. And perhaps most famously, Never invest in a business you cannot understand.
So when Buffett's friend and longtime partner in Berkshire Hathaway (BRKB), Charlie Munger, suggested early last year that they invest in BYD, an obscure Chinese battery, mobile phone, and electric car company, one might have predicted Buffett would cite rule No. 3 above. He is, after all, a man who shunned the booming U.S. tech industry during the 1990s.
But Buffett, who is 78, was intrigued by Munger's description of the entrepreneur behind BYD, a man named Wang Chuan-Fu, whom he had met through a mutual friend. "This guy," Munger tells Fortune, "is a combination of Thomas Edison and Jack Welch - something like Edison in solving technical problems, and something like Welch in getting done what he needs to do. I have never seen anything like it."
Coming from Munger, that meant a lot. Munger, the 85-year-old vice chairman of Berkshire Hathaway, is a curmudgeon who frowns on most investment ideas. "When I call Charlie with an idea," Buffett tells me, "and he says, 'That is really a dumb idea,' that means we should put 100% of our net worth into it. If he says, 'That is the dumbest thing I've ever heard,' then you should put 50% of your net worth into it. Only if he says, 'I'm going to have you committed,' does it mean he really doesn't like the idea."
This time Buffett asked another trusted partner, David Sokol, chairman of a Berkshire-owned utility company called MidAmerican Energy, to travel to China and take a closer look at BYD.
Last fall Berkshire Hathaway bought 10% of BYD for $230 million. The deal, which is awaiting final approval from the Chinese government, didn't get much notice at the time. It was announced in late September, as the global financial markets teetered on the abyss. But Buffett and Munger and Sokol think it is a very big deal indeed. They think BYD has a shot at becoming the world's largest automaker, primarily by selling electric cars, as well as a leader in the fast-growing solar power industry.