Vertical wireless charger cuts costs, improves efficiency
Wireless, or inductive, charging transmits data via a magnetic field between two pads, requiring no physical connection between the car and the charger, and is already commonplace in electric toothbrushes, as well as mobile phones.
There are numerous companies developing ground-based systems, which transmit energy to a receiving pad under the car, but Fraunhofer’s research has highlighted technical issues with this setup.
Ground-mounted pads need to transmit energy across gaps of up to 15cm, and longer distances require a more powerful and more expensive coil. The heat can also attract cats to sleep under the car, blocking the transfer, and can cause metallic paper such as chewing gum wrappers and cigarette packaging to burst into flames.
Fraunhofer’s system uses a waist-high vertical charging pole made of flexible plastic. It features a 150mm coil, rather than the typical 800mm coil used in ground-mounted systems, and can flip downwards enough to be driven over.
Because the receiver on the car is horizontal, drivers don’t have to line up perfectly, and the system can transfer energy at 3kW with 95% efficiency, charging at the same rate as a domestic wallbox.
‘Nowadays, charge spots are offered as part of the sales package when customers buy an electric vehicle. This technology will only become a mass product if the price is right.’