The further increase in the number of power-consuming functions which has been announced for future vehicle electrical systems, and in particular the effects of new starting systems on battery performance, requires a further optimization of the lead acid system coupled with effective energy management, and enhanced battery operating conditions. In the face of these increased requirements, there are proven benefits to splitting the functions of a single SLI battery between two separate, special-purpose batteries, each of which are optimized, for high power output and for high energy throughput, respectively. This will bring about a marked improvement in weight, reliability, and state of charge (SOC). The development of special design starter and service batteries is almost completed and will lead to new products with a high standard of reliability. The design of the power-optimized lead acid accumulator is particularly suitable for further development as the battery for a 42/36 V electrical system. This is intended to improve the efficiency of the generator and the various power-consuming functions and to improve start/stop operation thereby bringing about a marked reduction in the fuel consumption of passenger cars. This improvement can also be assisted by a charge management system used in conjunction with battery status monitoring.