BMW i has announced that market introduction of wireless charging for its vehicles will begin in a few months – its inductive charging system will be a factory-fitted leasing option first available on the BMW 530e iPerformance.

The BMW Wireless Charging system will enable electric energy from the mains supply to be transmitted to a vehicle’s high-voltage battery without any cables, charging being carried out when the vehicle is positioned over a base pad. The principal benefit here is ease of use, simplifying the process of recharging a plug-in hybrid by eliminating the need to hook the car up via a cable.

The system employs the same inductive charging technology already widely used for supplying power to devices such as mobile phones and electric toothbrushes, in this case to recharge batteries in electrified vehicles. The contactless transfer of energy is carried out via an electromagnetic field between the two components, which are located eight centimetres apart.

Primary components consist of an inductive charging station called a GroundPad, which can be installed either in a garage or outdoors, and a secondary vehicle component known as the CarPad, the latter fixed to the underside of the vehicle. The GroundPad generates a magnetic field, while the CarPad induces an electric current that then charges the high-voltage battery in the car.

In terms of positional accuracy, the system allows for some deviation in terms of optimum positioning by up to seven centimetres longitudinally and up to 14 centimetres laterally, but coloured lines shown via the Control Display help guide the driver while parking and a graphic icon shows when the correct parking position for inductive charging has been reached.

The system has a charging power of 3.2 kW and has an efficiency rate of around 85%, enabling the batteries on board a 530e iPerformance to be fully charged in around 3.5 hours. During charging, ambient electromagnetic radiation is limited to the vehicle undercarriage. Once the battery is fully charged, the system switches off automatically.

The GroundPad can be installed outdoors, and remains unaffected by adverse weather conditions. The automaker says that all components in the system that conduct electricity are protected from rain and snow, and driving over the GroundPad will not damage it in any way.

The rollout of the wireless charging system will start with Germany, subsequently followed by the UK, the US, Japan and China.