Wireless charging for electric cars the next step into what maybe becoming a ?wireless age? may be one of the innovations the needed to save the electric car.? One of the major complains from early adopters of electric vehicles, like the Nissan Leaf and Chevrolet Volt, is that cords are a problem ? they get tangled, they get dirty and they are a pain to always have to plug in.
Now a group of companies is working on ways to charge the batteries wirelessly, from a mat that sits on the floor.? The system uses coils under the car to engage the charger when the car is parked above them.? Because the mats are plugged in and transferring power to the batteries, it?s not necessary to physically plug the car into an electrical outlet.
According to Bloomberg News — Nissan, Delphi Automotive, Volkswagen’s Audi, Toyota, Mitsubishi, Qualcomm, Evatran and Brose Fahrzeugteile GmbH & Co. are among companies developing wireless chargers.
General Motors has invested $5 million in a private company called Powermat, but so far, the technology is only being used to wirelessly charge smartphones and other devices in the car.
Wireless chargers work one of two ways: by induction, similar to the way the battery on an electric toothbrush charges when it’s set back on its base, or by magnetic resonance.
The Delphi’s charger, using a technology developed by WiTricity, uses a magnetic field to transfer the charge between coils in the mat and a receiver about the size of a laptop computer, which is mounted on the underside of a car.? The system can have a gap between the two of up to about 10 inches.
A charger technology developed at the Massachusetts Institute of Technology, sends send 3 kilowatts of electricity quickly enough to recharge a battery in about four hours.? Two coils are tuned to resonate at the same frequency, creating the connection. Audi, Toyota and Mitsubishi also are working with WiTricity.
Magnetic resonance allows more margin for error than inductive charging when lining up over the mats.? Inductive chargers require more precise alignment for recharging.
When these wireless chargers reach the market they are expected to sell for more than $2,000, or at least twice the price of current charging stations. ?The wireless chargers are also less efficient, losing about 10 percent of power during transmission.
There are several other problems that need to be overcome, too, For example, a charging mat is flat and warm — an attractive place for the family cat.? Another problem is how to keep metallic objects away from mats.
Wireless charging could go a long way to helping electric car manufacturers develop new interest in a segment that is otherwise advancing very slowly.