Wireless electric vehicle charging technology continues to remain in its infancy to this stage, not being even remotely as common as charging stations scattered throughout the land and in personal garages. Japanese automaker Toyota may be looking to change this, however, announcing recently verification testing is to begin later this month of a new wireless battery charging system it has developed for vehicles that use an electric powertrain.
This new Toyota offering, similar to other wireless charging technology out there, allows a car to be charged simply by parking it in alignment with a coil set into the surface of the ground. The system transmits electricity using magnetic resonance created by changes in magnetic field intensity between the ground coil and a receiving coil in the car. It is reportedly designed “so that it can reduce any loss in power transmission efficiency caused by misalignment or height differences between the coils.”
The testing program will involve use of three Toyota plug-in hybrids, like the Prius Plug-in, which will be used in homes in Aichi prefecture in Japan. It will assess user satisfaction, the system’s ease of use, misalignment rates and charging behavior, such as how often charging takes place and timer-based charging it used.
Key technical specifications of the wireless technology include a 85 kHz frequency, input voltage of AC 200v, a charging power of 2 kW and, most important, a charging time of approximately 90 minutes. Also, to help the driver align the car correctly, a function has been developed for the car company’s Intelligent Parking Assist system, seen in the video below, that shows the position of the transmitting coil in a parking space.
Toyota said it will use the test results to develop the technology further, with the ultimate aim of bringing the system to market, though there was no immediate mention of when this might happen or where. Some measures being brought into play as part of this process include minimizing any electromagnetic interference with nearby equipment, and making sure the transmitting coil in the ground has been made robust enough to withstand vehicles driving over it.