Washington Post: Two big batteries stand side by side at the General Motors testing lab in Warren, Mich. One is an artifact, built a dozen years ago. Weighing 1,200 pounds, it could fill the back of a large pickup truck. Standing on one end, it towers over GM’s Robert A. Kruse, executive director of global vehicle engineering for hybrids and electric vehicles. The other battery is new and produces the same amount of energy but is a relatively trim 400 pounds. It comes up just past Kruse’s …