A123 Systems files for bankruptcy protection
A123 Systems Inc., a Waltham-based maker of lithium-ion batteries, filed for Chapter 11 bankruptcy protection in federal court in Delaware Tuesday morning, saying in court filings that it has agreed to sell such automotive business assets as its facilities in Michigan. In a recent regulatory filing, the company said that a default on some of its debt is likely. A123 bet heavily that its batteries would be ideal for helping to power electric and hybrid vehicles. The company has struggled in the last year, with layoffs and a recall of some batteries.