In a power supply apparatus for a vehicle, an inverter circuit inputs a voltage from a first battery unit through switches. A smoothing condenser is provided between the first battery unit and the inverter circuit in parallel. A DC-DC converter is provided between the smoothing condenser and a second...http://www.google.co.uk/patents/US6923279?utm_source=gb-gplus-sharePatent US6923279 - Power supply apparatus and electric vehicle using the same
