New vehicle electric systems are promoted by the needs of fuel economy and ecology as well as by new functions for the improvement of safety and comfort, reliability, and the availability of the vehicle. Electrically controlled and powered systems for braking, steering and stabilisation need a reliable supply of electrical energy.The planned generation of electrical energy (only when it is economically beneficial meaningful), an adequate storage, and thrifty energy housekeeping with an intelligent integration of the battery as the storage medium into the overall concept of the vehicle Energy Management, and early detection of possible restrictions of reliability by Battery Monitoring allows for actions by the Energy Management well in advance, while the driver need not be involved at all.To meet today's requirements for Battery Monitoring and Energy Management, solutions have been developed for series vehicles launched in years 2001-2003, operating at the 14 V level. (C) 2003 Elsevier Science B.V. All rights reserved.