Lead–acid batteries for hybrid electric vehicles and battery electric vehicles

Abstract This chapter provides a description of the working principles of the lead–acid battery (LAB) and its characteristic performance properties such as capacity, power, efficiency, self-discharge rate, and durability. Environmental and safety aspects are discussed, and it is made clear that the battery can be employed safely and sustainably as long as appropriate precautions are observed. A central theme of the chapter is a consideration of the diverse types of battery—starting, lighting, and ignition (SLI), enhanced flooded battery, and absorptive glass mat—that have been developed for different automotive applications such as SLI and stop–start operation in microhybrids. In this latter connection it has been recognized that the inclusion of carbon integrated into the negative plate of the battery in different ways can give rise to a huge improvement in performance. It is pointed out that batteries deploying the lead–acid chemistry in the microhybrid application have the lowest specific additional cost for the reduction of carbon dioxide emissions (€/% CO 2 reduction). An application of lead–acid in mild hybrids (12 V or even 48 V) would be possible if the dynamic charge acceptance and the total cycling throughput could be improved. The use of advanced LABs in dual systems with lithium-ion batteries would also be possible. Potential further improvements of the battery (e.g., through the use of optimized grids, bipolar designs, or additives) is discussed as is the use of LABs in engine downsize and boost concepts. A market forecast showing that in 2020 more than 50% of all cars will be microhybrids with LABs rounds off the chapter.