Mercedes-Benz claims battery breakthrough

Mercedes-Benz to launch the first hybrid car based on lithium-ion batteries.

Wayne Cunningham Managing Editor / Roadshow
Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.
Wayne Cunningham

Mercedes-Benz S400 BlueHybrid
The Mercedes-Benz S400 BlueHybrid will use lithium ion battery technology. CNET Networks

Current mass-produced hybrid cars use nickel-metal hydride batteries, but Mercedes-Benz says it will launch the first hybrid with lithium ion batteries. Lithium ion batteries are more efficient than nickel-metal hydride batteries and have a better weight-to-power ratio, and are used in the all-electric Tesla roadster as well as in many plug-in hybrid conversions. But large stacks of lithium ion batteries can overheat, a serious problem in an automotive application. Mercedes-Benz announced it has 25 patents around making lithium ion suitable for cars, detailing a key breakthrough of integrating the battery with a car's climate control system, which maintains the battery temperature at between 60 degrees and 95 degrees Fahrenheit. In this temperature range, lithium ion batteries offer optimal performance and long life.

Mercedes-Benz will first use lithium ion batteries in its S400 BlueHybrid, launching in 2009. The S400, unveiled at the 2007 Frankfurt auto show, will use a 3.5-liter V-6 engine complemented by the hybrid system. Mercedes-Benz claims 30 mpg for the S400 and a 0 to 62 mph time of 7.3 seconds with its 300 horsepower.