Electric vehicle battery charger

The traction battery 22 of an electrically powered vehicle is charged via an inductive coupling between a primary inductive circuit 12, energised from a supply 11 via a rectifier and high frequency inverter 16, and a secondary inductive circuit 18 mounted on the vehicle and connected to the battery 22 via a rectifier 20, the charging system having means to compensate for misalignment between the primary and secondary circuits 12, 18. The operating frequency of the primary circuit is maintained in a range from a selected resonance frequency of the primary circuit to a frequency which is less than a selected resonance frequency of the secondary circuit. A remote control arrangement including transceivers 26, 28 may be provided to maintain this condition. Tunable capacitors may be provided in the primary and secondary circuits, the resonant frequency of the secondary circuit may be established when the primary and secondary circuits are optimally inductively coupled, and the capacitance may be adjusted so that the primary circuit resonates at a frequency below the secondary circuit resonant frequency.