 In simple terms, inductive charging works by separating the two halves of an electric transformer with an air gap – one half, the Plugless Power Vehicle Adapter, is installed on the vehicle and the other half, the Plugless Power Parking Pad, is installed on the floor of a garage or in a parking lot.When a car with an Adapter drives over a Pad, the two pieces are brought into close proximity, , then current from the electrical grid flows through the coils in the Power Pad to create magnetic fields and these fields induce current flow in the Vehicle Adapter's coils to charge the battery.Idaho National Laboratory (INL) testing in 2013 found the system had a power delivery efficiency between 84%-90%, compared to 95%-99% for corded charging systems, depending on the alignment of the Adapter and Pad, the separation gap, and the rate of power transfer in use (kW).