General Motors announced yesterday that it would replace the 120-Volt charging unit provided with every Chevrolet Volt, to provide what GM spokesman Randy Fox called a "more consistent charging experience." Back in July, we reported that some of the charging units provided in Volts were overheating, becoming too hot to touch and in one case, even giving an owner a second-degree burn. Thicker cord Now, after complaints from Volt owners, General Motors has agreed to swap out the unit for a beefed-up unit of the same design. Fox said upgrades to the design include a thicker cord from the unit...