Wireless or inductive charging has existed for 100 years since Nikola Tesla first demonstrated magnetic resonant coupling. There was little or no need for the technology at the time, so it faded into obscurity. Today, wireless technology presents new opportunities for all electronics that charge. This technology is back on the radar thanks to its use in small devices. But wireless charging has many more unexpected uses than merely cell phones.
Major brands have all embraced the new technology. There are several wireless standard charging groups that represent certain brands. The Wireless Power Consortium (WPC) includes technology power houses such as Apple, Verizon, and Google. The AirFuel Alliance, created in 2015, includes Duracell, Dell, Samsung, and Qualcomm.
According to David Green, research manager with IHS Markit, for Computer World, there are three types of wireless charging. “There are charging pads that use tightly-coupled electromagnetic inductive or non-radiative charging; charging bowls or through-surface type chargers that use loosely-coupled or radiative electromagnetic resonant charging that can transmit a charge a few centimeters; and uncoupled radio frequency (RF) wireless charging that allows a trickle charging capability at distances of many feet.”
The idea is to transmit electricity through the air by creating a magnetic field between two circuits, a transmitter, and a receiver. A copper coil, or magnetic loop antenna, is used to create an oscillating magnetic field, which creates current in one or more receiver antennas. The correct capacitance (the ability of a system to store an electric charge) is needed to make loops vibrate at the same frequency. The current increases, creating resonant inductive charging, which allows power transmission at distances and increases efficiency.
It may sound a little complicated, but basically, it’s charging without the wires, and the bigger the coil, the further distance the charge can travel. Most coils are very small, designed to be used in small devices. But can the technology be used for more than cell phones?
WiTriCity, a Massachusetts company that licenses technology developed at MIT, is focused on electric vehicles. Their electromagnetic resonant technology allows a charge from nine inches away, meaning an EV could simply park on top of a large charging pad. Energy is transferred between the pad on the floor and the pad underneath the car through resonant magnetic induction, and the car can charge- hands and wire free.
Mercedes announced a wireless entry to the market in 2018. Many other EV manufacturers- from Chevy to Porsche -are excited about the new technology. Several retailers predict faster charging with no hassle from dirty cords or bad weather conditions says Plugless Power.
According to Green Car Reports, Jesse Schneider, chair of the SAE task force said, “Charging your EV should be as simple as parking and walking away—the wireless charging SAE J2954 standard gives freedom to do exactly that, safely and automatically.” The opportunity to simply park on a flat pad charger would be an easy and efficient option for drivers.
While everyone knows EVs are better for the environment, not many would have said recharging EVs is big on convenience. But now, the driver doesn’t even need to get out of the vehicle, a step up from conventional vehicles.
When will wireless charging be mainstream for EVs? As soon as possible. Car companies are excited to soon offer this amenity, and cars with wireless charging should be on the market in 2022, even late 2021.