Battery maker Boston-Power is closing on a round of $250 million from investors in China and elsewhere, reports the Wall Street Journal’s Venture Capital Dispatch blog. The company, founded in 2005 in Massachusetts, originally made lithium ion batteries for consumer electronics, but in 2011 launched its electric car lithium ion battery tech. Shortly after that, Boston-Power moved the bulk of its operations to China and raised a round led by China-based investor GSR Ventures. The WSJ report says Boston-Power has battery factory capacity for 300 megawatt-hours of batteries (with annual sales of $100 million) and next year plans to more than triple that factory capacity. The company is providing batteries for electric cars made by Beijing Electric Vehicle Company.