Method of identifying a defective battery or a battery free condition in vehicle on board electronics by monitoring voltage cycle at different times

摘要

The method identifies a defective battery or absence of battery (3) in an electric network (6) powered by a battery (3) and a generator (1). The method involves determining the wave shape of the network voltage at different times and monitoring this relative to a threshold. The voltage can be supplied to a diagnosis unit (4) with an analog to digital convertor (5) for calculating an average value of the wave. Independent claims also cover an apparatus for carrying out the method.