Wireless charging for cars is still too far away.

Wireless charging for mobile phones is common, but it is still rare for new energy vehicles.

Recently, the U.S. Patent and Trademark Office disclosed four technical patents related to wireless charging for vehicles owned by Tesla, and Tesla's future vehicles are also expected to gain wireless charging capabilities based on magnetic resonance and other solutions.

As early as March of this year, Tesla included an inductive charger interface in the Cybertruck to match subsequent wireless charging devices.

In 2023, Tesla acquired Wiferion, a German wireless charging startup, but soon sold the company's operations and manufacturing business to PULS, a German power electronics supplier, and retained Wiferion's engineering team.

There are signs that Tesla has some interest in wireless charging for vehicles, and it was willing to buy an entire company just to acquire an engineering team. Wireless charging in the new energy vehicle field is also not uncommon, but it has not been widely commercialized. Will Tesla pave the way for wireless charging for vehicles?

Tesla is not the only one "eating the crab" in the field of wireless charging for vehicles

Franz von, the Chief Designer of Wiferion, confirmed in an interview with Jay Leno that Tesla is developing a wireless charging solution for homes. This indicates that Tesla has not abandoned wireless charging technology and has even found a suitable application scenario for it. However, currently, Tesla's main move has been to add a wireless charging hardware interface to the Cybertruck, which does not directly support wireless charging.

It is reported that Wiferion's wireless charging technology can provide up to 93% charging efficiency and has a 40mm tolerance for vehicle positioning.

From the patents, wireless charging for vehicles only requires two devices: a "transmitting coil" placed in the parking space and a "receiving coil" integrated into the vehicle. Once these two coils are inducted, the vehicle can be charged. This principle is similar to that of wireless charging devices for smartphones, which transmit energy through electromagnetic resonance, but magnetic resonance wireless charging technology can achieve higher charging efficiency and longer transmission distances compared to electromagnetic induction.

Magnetic resonance wireless charging is more suitable for electric vehicles.

Ideally, the layout of these two devices is not difficult. It is speculated that wireless charging kits will be sold to individual users, connected to household circuits, and fixed in place without the need for additional modifications, similar to household AC charging piles. Electric vehicles tend to stay parked at home for longer periods and generally do not require fast charging, making them ideal scenarios for AC charging piles and wireless charging devices.

Wireless charging for vehicles may sound niche and unfamiliar, but Tesla is not the only automaker to venture into this field.

WiTricity has partnered with BMW to create the world's first BMW 530e iPerformance equipped with wireless charging from the factory. The vehicle can automatically charge when parked over a pre-buried magnetic resonance coil and is a plug-in hybrid model currently available in multiple countries.

IM Motors, a domestic new energy vehicle maker, also has a model, the L7, equipped with wireless charging technology, with a charging power of up to 11kW.

Qualcomm's Halo wireless charging technology debuted at CES 2012, utilizing magnetic resonance to achieve contactless charging for vehicles with an output power range of 3.3-20kW and an overall efficiency greater than 90%. The second generation of this technology was used in the 2015 Formula E electric racing series, with a wireless charging power of 7.2kW, allowing cars to be fully charged in one hour. Moreover, Qualcomm's Halo system supports not only static charging but also semi-static and dynamic charging technologies, enabling charging even while the vehicle is moving at high speeds.

Domestic suppliers such as Innosense have achieved high-power wireless charging products with single-phase 7kW and three-phase 11kW capabilities, marking breakthroughs in charging efficiency and offset tolerance technology. Echoing this trend, Yichuang Zhilian, specializing in the development of medium-to-high-power wireless charging products, has achieved the world's first mass production of 11kW wireless charging products for electric vehicles. Additionally, suppliers like Momentum Dynamics, HEVO POWER, Evatran, and Robert Bosch GmbH are also actively researching and promoting wireless charging solutions for vehicles.

This seemingly inconspicuous new field has already attracted many players. However, for new energy vehicles, both battery swapping and wireless charging are relatively new forms of energy replenishment in terms of coverage, and require cooperation between automakers and charging service providers for promotion. Time will ultimately determine when wireless charging for vehicles will see widespread adoption.

Commercialization of wireless charging for vehicles: "painless energy replenishment" is not the key

Wireless charging technology for vehicles has been under development even before the rise of new energy vehicles. From a technical perspective, various solutions are maturing, and efforts are being made to commercialize them.

Like smartphones, contactless charging is more seamless in daily life. Instead of plugging in a cable, wireless charging simply requires placing the phone on a charging pad, making it easier to replenish energy during fragmented times and psychologically "ignoring" the charging process. Similarly, for new energy vehicles, as long as they support wireless charging, they can start charging immediately upon parking in the designated space, offering a more elegant solution than getting out to plug or unplug the charging gun. The key is that it makes charging "painless."

However, "painless energy replenishment" alone cannot justify the widespread adoption of wireless charging for vehicles. When charging electric vehicles outside the home, users prioritize charging efficiency.

While various solutions predominantly utilize magnetic resonance and boast impressive charging efficiency ratings, charging powers tend to be relatively low. Common single-phase 220V AC charging offers 7kW, while three-phase 380V power sources typically achieve 11kW, with the highest European standard three-phase AC power reaching only 48kW, paling in comparison to DC fast charging.

In simple terms, while wireless charging for vehicles is convenient to deploy, its power output is similar to that of conventional AC charging stations. Wireless charging merely addresses the issue of "plugging in the gun" but does not solve the efficiency problem inherent in electric vehicle charging.

Why is Tesla targeting the home scenario for wireless charging technology? I believe it's because most home charging facilities are relatively fixed, connected to either 220V single-phase or 380V three-phase AC power, and primarily used for long-term charging of electric vehicles parked in garages. Considering that wireless charging units are easy to install and offer comparable power to contact-based AC charging, they can easily replace traditional methods.

Moreover, contactless charging may help avoid issues like "violent gun extraction."

Public charging stations, on the other hand, have different electricity pricing standards than households, and public parking areas are not intended for long-term stays by electric vehicle users. Prolonged stays may incur additional parking fees and overtime charges, making wireless charging economically unfeasible at present.

Issues such as overheating and slow charging, which are common with wireless charging for mobile phones, are likely to persist in vehicles as well.

Considering practical factors like significant misalignment between parking positions and charging coils, resulting in reduced charging efficiency, and the question of who should bear the energy loss associated with contactless charging, these challenges may ultimately hinder the commercialization of wireless charging for vehicles. Few automakers, like NIO, can invest significant time and capital into building battery swapping and charging networks, making the successful implementation of wireless charging reliant on cooperation between automakers, service providers, and technology suppliers.

Optional installation may not be the final outcome for wireless charging in vehicles

Tesla's insights are astute, accurately identifying the limitations and use cases of wireless charging technology in vehicles – home charging represents the most ideal and "painless" application of this technology at present.

In other words, once wireless charging technology reaches a commercially viable standard, Tesla may introduce wireless charging units through optional installation and accessory sales, potentially making wireless charging an option for new vehicle configurations.

While wireless charging is currently limited to scenarios where vehicles can be parked for extended periods, and charging efficiency has yet to see breakthroughs, I believe optional installation and home use are not necessarily the final outcomes for wireless charging in vehicles.

As the saying goes, "laziness drives progress." When people didn't want to get out of their cars to plug in charging cables, Lotus Cars introduced automated robotic charging arms. During Lixiang's first Family Tech Day in June 2023, an automated charging robot technology was also unveiled.

The advantage of automated charging robots lies in their full automation, which allows them to visually recognize and interact with vehicles, automatically plug in charging cables, and settle payments, eliminating the need for drivers to exit their vehicles.

While this unmanned charging technology sounds promising, its construction costs are higher than traditional charging cables, making it more challenging to popularize. Wireless charging, which does not require drivers to exit their vehicles, is a more practical solution. However, even the concept of a wireless charging road, designed to work in conjunction with wireless charging, has only been implemented over a few kilometers, making global popularization seem far-fetched.

While the "painless" aspect of wireless charging may appeal to those who prefer not to exit their vehicles to charge, technological advancements must also address charging efficiency. Only by solving the issue of charging power will wireless charging become a mainstream energy replenishment method for electric vehicles.

It's still early days, and there are many untapped secrets in new energy vehicles. Perhaps some automakers will follow Tesla's lead and work together to expand the "ecosystem" of wireless charging.

Source: Leitech