Audi is the forefront of wireless charging technology, with an inductive charging system currently in development for release in 2017 and a more powerful version coming soon after.
Wireless charging technology works by using an alternating electromagnetic field from the base plate that induces an alternating current in the car's secondary coil across the small air gap. This allows an onboard AC/DC inverter to transform from AC to DC to then supply the high-voltage electrical system.
The first iteration of Audi's wireless charging technology uses a 16A current supply to produce 3.6kW using inductive charging, but a more powerful 11kW system is on the way in the next version. Audi envisages that the 3.6kW unit will operate at consumer's homes, while the larger 11kW version could be installed in heavy industry and along roadways.
While the system currently requires drivers to line up the vehicle's charging plate with the floor plate, future iterations will allow drivers to get out of the car and use a smartphone to automatically position the vehicle in an ideal place over the charging plate.
The small air gap between the charging plate and the vehicle's body offers no electrical interference to surrounding devices and is entirely safe when not in use, so it could live laying flush on a garage floor happily when it's not in use.