For future vehicles, the 42-V power system offers a variety of new applications, from the capability to sustain increased comfort loads up to mild hybridization. To meet these requirements, considerable progress is ne. Because of the pressure on vehicle component costs, the commonly used lead–acid battery is a. The key task for the battery is first and foremost to start the engine. Increasing quiescent currents required by the multitude of electronic equipment of high-end ('luxury') car. Basically, the limitations of the lead–acid system are caused by its electrochemistry. The cell voltage, which is numbered among the principal advantages of lead–acid, well exceeds (by 1 V). As soon as high cycle numbers, high service life, and low extra volume and weight are required, the drawbacks of lead–acid imply the use of Ni–MH or Li-ion battery systems. As the data presented illustrate, the requirements of the different applications determine the usability of lead–acid battery systems in cars. Because of the low cost and the high recy.
