Ecotality Inc., a maker of electric-vehicle charging stations that was awarded a grant of nearly $100 million by the Energy Department four years ago, has filed for chapter 11 protection on Monday and plans to auction off its assets next month, the Wall Street Journal reported today. The company said that eight potential buyers have expressed interest in bidding on its assets at a proposed Oct. 9 auction. Nissan North America Inc. has agreed to provide Ecotality with a $1.25 million loan to fund the Chapter 11 case pending the sale. The company makes charging units for Nissan’s Leaf electric car. Ecotality said last month it was exploring a restructuring or sale, citing payment suspensions from the U.S. Department of Energy, which awarded the company a $99.8 million grant in 2009 to manage the deployment of a nationwide network of electric-vehicle charging stations known as the EV Project. Ecotality owes the Energy Department $6.5 million, according to court papers.