Electrical supply device for a motor vehicle and methods for control of such a device

摘要

The starter battery (2) is permanently associated only with the starter (1), the second (''service'') battery (3) only with loads (51), e.g. lamps, heaters, not concerned with engine operation or vehicle security. In the controller (6), one switch position (T1) separates the starter battery from the remaining loads (50), including ignition, injection, pre-heating, emission control and ABS equipment. Another (T2) separates the latter from the alternator (4), a third (T3) the alternator from the service battery (3). Switching, diode or other control devices occupy at most two positions, the other(s) being short-circuited. Battery states are continuously monitored. Numerous options are described, providing various advantages under different operation conditions, e.g. inter-battery back-up, service load voltage unaffected during starting, starter battery unaffected by lighting left on, etc., etc..