The wireless charging is being tested out in the BMW 530e iPerformance model. The BMW 530e iPerformance saloon combines a conventional petrol engine with an electric motor in order to deliver both power and ultra-low benefit-in-kind cost savings. The cost of the standard model is around $60,000.
The principle behind the new wireless charging is where a primary coil is integrated into a base plate (this is fitted beneath the vehicle, such as on the floor in a garage or in a parking lot). This coil functions to induce electric energy into a secondary coil, which is fitted in the car floor. A Wi-Fi connection, between the charging station and vehicle, directs the energy to the right spot. This technology works similar to the wireless charging systems we use for mobile phones and electric toothbrushes.
The development means that future BMW vehicles will have wireless charging capability. The hardware that will enable the wireless charging is composed of an inductive charging station, a platform called GroundPad.
The GroundPad device can be fitted to garages and also outdoors. A second item of hardware is called CarPad, which is fitted to the vehicle underbody. The system works, according to Smart2Zero, through a contactless transmission of energy occurring between the GroundPad and CarPad. This functions over a distance of some eight centimetres.
With this, the GroundPad produces a magnetic field. As a current is induced in the CarPad, this serves to charge the high-voltage battery. The overall charging capacity is 3.2 Kw. To charge a battery in the car, the time required is three and a half hours. In terms of tests to date, the efficiency of the overall system is close to the level achieved in relation to charging with cables.
In terms of safety features the ground pad is assessed for foreign objects. Once an object is detected, the wireless system shuts down the charging process.
With the charging system, once the vehicle is placed in the parking position by the driver, the charging process triggers automatically once the engine is turned off. The aim here is to make the charging activity far easier to initiate than with conventional refuelling.
In the short term, the equipment for wireless charging will only be made available for leased vehicles.
