Patent ID: 6765312
Filing Date: 2004-07-20
Classification: B60R,H02J,Y02T

Abstract:
A method for starting a motor vehicle using a two-battery system, the two-battery system including:a starter battery; an electrical-system battery; a starter; a plurality of electrical consumers, the electrical consumers including at least one start-relevant consumer and at least one electrical-system consumer; at least one first starter switch arranged between the starter and the starter battery; a second starter switch arranged between the starter and the electrical-system battery; a first electrically fully-blocking switch element arranged between the starter battery and the start-relevant consumers; a second electrically fully-blocking switch element arranged between the electrical-system batter and the start-relevant consumers; and an arrangement arranged between the starter battery and the electrical-system battery configured to prevent a current flow from the starter battery to the electrical-system battery and the electrical-system consumers; wherein the start-relevant consumers are configured to be assigned to a battery via the first electrically fully-blocking switch element and the second electrically fully-blocking switch element prior to initiation of a starting operation, by which the start-relevant consumers are to be powered during the starting operation, and wherein the start-relevant consumers are configured to be assigned to the electrical-system battery after termination of the starting operation, the first electrically fully-blocking switch element configured to be opened only after closing the second electrically fully-blocking switch element in accordance with essential switching operations of the first electrically fully-blocking switch element and the second electrically fully-blocking switch element after a starting phase; comprising the steps of: determining a charge state of the starter battery and the electrical-system battery prior to initiating the starting operation; assigning the start-relevant consumers to the battery by which the start-relevant consumers are to be powered during the starting operation in accordance with connection of the first electrically fully-blocking switch element and the second electrically fully-blocking switch element; switching the starter switching through from the assigned battery, the starter switches remaining switched through until high-load starting consumers are deactivated; and assigning the start-relevant consumer to the electrical-system battery after termination of the starting operation, the first electrically fully-blocking switch element opened only if the second fully-blocking switch element was previously closed, in accordance with essential switching operations of the first electrically fully-blocking switch element and the second electrically fully-blocking switch element after the starting phase.