Peer-to-peer highway EV charging would use telescoping cables between moving cars

Imagine a future where your EV was getting low on charge ­on a highway road trip – so you deploy a telescoping charging cable to another EV and borrow a few kilowatt-hours. An engineering professor at the University of Florida believes it’s not far-fetched.

We’ve seen a host of mobile EV charging van concepts. And there are proposed solutions for stationary robots to connect a vehicle to a charger, like what Kuka Robotics demonstrated last year (shown above).

The new idea is to merge the two so EVs on the move can connect with one another and with mobile charging stations. (Apple filed a patent for something similar in 2018.)

A few weeks ago, Swarup Bhunia and his colleagues at UoF’s electrical and computer engineering department posted a paper explaining how it would work. Here’s part of the Abstract:

We propose Peer-to-Peer Car Charging (P2C2), a highly scalable novel technique for charging EVs on the go with minimal cost overhead. We allow EVs to share charge among each other based on the instructions from a cloud-based control system.

The control system assigns and guides EVs for charge sharing. We also introduce Mobile Charging Stations (MoCS), which are high battery capacity vehicles that are used to replenish the overall charge in the vehicle networks. We have implemented P2C2 and integrated it with the traffic simulator, SUMO. We observe promising results with up to 65% reduction in the number of EV halts with up to 24.4% reduction in required battery capacity without any extra halts.

In other words, two EVs link up to one another with telescopic charging booms. By creating a network of electric vehicles sharing energy, the researchers believe drivers would have to stop a third as often. Here’s how the connector could work:

We envision a safe, insulated, and firm telescopic arm carrying the charging cable. After two EVs lock speed and are in range for charge sharing, they will extend their charging arms. The arms heads will contain the charging ports, and they will latch together using either magnetic pads or other means. The arms and the overall charging operation will be coordinated by the respective arm controllers of each EV. This is just one possible realization of the charge transfer mechanism.

That could allow automakers to produce EVs with smaller packs. But it would require a redesign of battery systems, in which there would be a separate battery used for the exchange of energy on the fly. (Maybe Nio will pick up on the idea. What is Better Place’s Shai Agassi up to? Elon?)

Professor Bhunia describes the Mobile Charging Stations as “high battery capacity vehicles that are used to replenish the overall charge in the vehicle networks.” The MoCS would augment the capacity of P2P charging when it might be difficult to borrow juice from a fellow EV driver. The paper’s illustration shows that mobile charging stations might utilize drones.

Of course, there’s the problem of safety making those connections. You would need high levels of connected autonomy like used by jets sharing fuel ­– as well as robotic charging arms like the concept recently unveiled by Volkswagen. There would also need to be a central transaction management system for credits by the dollar or kilowatt-hour.

Electrek’s Take

Neat idea, but maybe not so realistic. Traffic safety regulators might have some concerns about high-voltage exchanges of power between cars traveling at highway speeds.

On the other hand, highly efficient highway platooning has been the dream of autonomous-vehicle proponents for a long time. Why not get a charge at the same time?

This idea might need to be put on the shelf until Level 4 and Level 5 (and robotaxis) actually arrive. That was supposed to be any day, but those timelines keep getting pushed off into an indefinite future.