Patent ID: 7403016

Claim:
A car power source apparatus comprising: a battery having a plurality of battery modules connected in series on positive and negative sides of a midpoint reference node; a voltage detection circuit that detects the voltage of one or a plurality of battery modules with respect to the midpoint reference node of the battery, the voltage detection circuit being connected on positive and negative sides of the midpoint reference node, the battery midpoint reference node being connected to the voltage detection circuit via a plurality of reference connection lines; and at least one conduction detection circuit for detecting abnormal conduction including a contact failure and an open circuit in each of the reference connection lines, supplying voltage from the battery modules to each of the reference connection lines to forcibly pass a current, and detecting current in each of the reference connection lines, the conduction detection circuit being connected to the reference connection lines separately with respect to the voltage detection circuit, wherein the connection status of each of the reference connection lines to the midpoint reference node can be detected via the conduction detection circuit.