Mercedes S400 Hybrid Review

Well, I've just driven the world's first mass-production automobile that employs a lithium-ion battery (the lithium-ion-using Tesla Roadster being a low-production affair). No, it isn't a full electric vehicle as Dr. MacCready would have preferred. But there, tucked in the corner of the Mercedes-Benz S400 Hybrid's engine bay, was a 32-cell, 120 volt, 0.9 amp-hour, lithium-ion battery about the size of shoebox.
For lithium-ion's first foray into mass production, the finicky battery type (dogged by YouTube videos of burning laptops) is getting kid-glove treatment. The most important kindness given it is cooling, performed by the AC system's refrigerant which is circulated by an electric motor (this required to provide air conditioning while the engine is shut down.) To give you an idea how pampered this battery is, when we asked how long it'll endure before replacement, Mercedes' engineers responded, "It'll last as long as the car itself" That's become a common claim about nickel-metal-hydride batteries, but I suspect both Tesla's and Chevy's Volt engineers are blanching at that proclamation being applied to lithium.