One day electric cars and trucks could charge each other on highways

Imagine driving down the highway on a long-distance journey and you realise your electric car is low on battery. Getting to the nearest DC fast charger will leave your battery near empty, or worse still the car runs flat before you get there.

This is the embodiment of “range anxiety,” often cited as a major barrier for uptake of electric vehicles, even though running out of petrol or diesel is probably just as likely to happen to drivers of internal combustion engines.

On long-distance highways, though – such as in Australia’s outback – the challenge of how and where to recharge is real.

One team of researchers believe a peer-to-peer charging system that allows electric vehicles to “lend” energy to another vehicle could be an answer to this problem.

Their theory, published in January 2020 as a pre-print (that is, it is yet-to-be peer reviewed) on arXiv, describes a system whereby an electric car’s battery is divided into two portions – one to power the car and one to accept power.

Swarup Bhunia, co-author of the proposal and director of the University of Florida’s connected world institute, explained to IEEE Spectrum that it could be especially useful for electric trucks – as much as “an extra 20 miles of range” could be transferred, he suggests.

The peer-to-peer charging car system (dubbed P2C2 by the paper’s authors) would work by joining two vehicles with extendable, telescopic and flexible arms with charging connectors on the end – all the time driving down the open road.

Naturally, both vehicles would also require V2X (in this case, vehicle-to-vehicle) technology to be able to share power.

It may sound far fetched, but would be perfectly safe to execute using autonomous driving technology, guided by a cloud-based network to determine the location and state of charge of participants, the paper’s authors surmise.

According to the pre-print, as much as 65% of electric vehicle stoppages could be avoided using the peer-to-peer system, and electric vehicles batteries could be about a three-quarters the size of current batteries without any extra stops to recharge.

The benefit for the driver then is not just a reduction in range anxiety, but also a more affordable electric car.

Charging another driver’s car wouldn’t be done under goodwill either. Bhunia was quoted as saying by IEEE that he believes that credits or payments to participate in the peer-to-peer charging system would be managed by the cloud network.

“They wouldn’t donate power,” Bhunia was quoted as saying.

“They’d be getting the credit back when they are in need. If you’re receiving charge within a network, one central management system can do it. But if you want to share between networks, that transaction can be stored in a bank as a credit and paid back later, in kind or in cash.”