BYD battery to bring electric cars into mainstream

China’s BYD Auto has devised a ferrous-ion electric-car battery it says is cheaper and greener than lithium-ion batteries, but the battery faces one serious obstacle – it can’t be charged in a household electric socket.

Ferrous ion is cheaper and more plentiful than the lithium ion traditionally used in electric car batteries. Warren Buffet’s Berkshire Hathaway invested $230 million in BYD last year, on the assumption that the technology could bring electric cars into the mainstream market.

BYD’s E6 sedan runs on a ferrous-ion battery – it can travel 400km per charge, but is designed for 10-minute, 50% charges, that last 200km. Charging, however, requires a dedicated, high-voltage charging station.

According to the Vancouver Sun, the company is working on the problem with Chinese power companies, the government and large fleet owners, like taxi companies, hoping for a breakthrough in time for the end-2009 launch of the E6.

BYD hopes to launch the E6 in North America in 2011.