DETROIT – General Motors has boosted the electric charge range, and consequently the miles-per-gallon equivalent (MPGe) on the 2013-MY Chevrolet Volt. The new charge range is 38 miles, increasing MPGe from 94 to 98, and the total range for the vehicle to 380 miles.

The automaker increased the Volt’s battery’s storage capacity from 16 kWh to 16.5 kWh and the state-of-charge window from 10.3 kWh to 10.8 kWh for the 2013 model.

The charge time for the 2013 model-year Volt will be longer than the 2012 model, due to the greater EV-only mode range, with a full charge taking 4.25 hours on a 240V charging system and 10.5 hours on a 120V system.

GM said its engineers made changes to the material composition of the battery cell’s chemistry. The battery still uses manganese spinel chemistry, but the automaker changed the amounts used to get better performance.

“The best way to explain what we’ve done at the cell level is to compare it to a cake batter recipe. Sometimes if you use more sugar and less vanilla you get a better tasting cake. We’ve done some work at the cell level to modify the ‘ingredients’ to make a better end result,” said Bill Wallace, GM director of Global Battery Systems Engineering. “This attention to detail will allow our customers to experience more pure EV range, which is the true benefit of owning a Volt.”

Vehicles using the improved battery cells have accumulated 150,000 test miles to date, GM stated. The tests also show less battery degradation and the ability to endure temperatures as low as -30 C.