A Guide to Wireless EV Charging
Inductive charging could make electric-vehicle ownership easier.
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The automotive world has yet to settle on an industry standard for EV charging equipment. Different countries use different connector designs, and in the United States alone, there are four different plugs in play. It brings to mind the early days of cellphones, when it seemed as though every company had its own type of charging port and finding the right equipment to power your stuff could be annoying and anxiety producing. Wireless charging may help reduce these inconvenient incompatibility issues, potentially making EV ownership more attractive. Plus, this technology could be critical to the deployment of fully automated electric vehicles, as they may not always have riders who can plug them in when their batteries run low.
In 2020, SAE International published the first global standard, called SAE J2954, for charging electric vehicles wirelessly. It establishes in-vehicle and ground-assembly requirements as well as minimum performance, safety, and testing standards for wireless power-transfer systems. If manufacturers adopt this, EV owners likely won't need to mess around with adapters or seek out equipment with a specific plug design. Charging a vehicle could become as simple as parking your car over a pad and walking away.
How Does Wireless Charging Work?
Wireless power transfer for EVs would function similarly to wireless charging for smartphones. A transmitting pad connected to the electric grid (called the ground assembly) delivers energy to the vehicle's receiving pad (known as the vehicle assembly) via magnetic field. That electricity is then stored in the electric car's battery. Wireless EV charging differs from wireless smartphone charging in one significant way, however: It will work across an air gap, meaning the vehicle assembly does not need to be in direct contact with the ground pad.
When Will EV Wireless Charging Be Available?
Several startups are collaborating with automakers to develop engineering kits or infrastructure to give wireless-charging capability to plug-ins. Plugless Power, for instance, offered a conversion package specifically for the Tesla Model S, although the company is not currently selling new products. HEVO and WiTricity plan to offer similar kits for many EVs by early 2024. Additionally, WiTricity lent its patented technology to the Genesis GV60, the first production vehicle to feature factory-installed wireless charging. It's currently available in South Korea.
The next frontier is dynamic wireless charging, which uses transmitters embedded in the road to charge EVs on the go. Michigan recently awarded a grant to Electreon to build the first mile of road with wireless charging in the U.S. The system will be built in Detroit and charge both moving and stationary EVs.
