Light and no ‘air gap’
In the end, a conductive solution was chosen for its lightness -- an inductive charging component would weight 25 kg compared with CES’ solution, which weights 2 kg -- as well as the elimination of an air gap, which lowers the charging efficiency of inductive and wireless charging solutions.
“There are other companies looking at similar solutions and with different approaches. We have also seen robot applications that connect from the side,” he said. “We investigated all these ideas and solutions, and from our point of view, the Volterio solution seems to be the most practical.”
Rupprecht declined to name specific automakers but said there is a letter of intent from at least one and said once the solution reached a certain market share, CES could open talks with energy companies or charging equipment companies as well.
One of the main technical challenges was designing the connectors on both the vehicle and ground units in a way that they were protected from any kind of dirt.
“On the car itself, just by driving it the connector could get dirty, especially during winter with salt spray and things like that,” Rupprecht said. “So, we have to protect the device on the car, and it's the same issue for the ground unit, even if it is just in your garage.”
The solution was to develop covers for both connection units that retract at the last possible moment before joining up.
“Our objective is to develop another solution that we can use in public parking as well, and another version later on which can be used for commercial vehicles where we then can transfer a higher amount of energy,” Rupprecht added.
Other approaches remain visionary
Volkswagen Group Components has also been working on a mobile charging robot, which at this point remains more of a conceptual vision than a workable product but could also find use in parking garages or restricted parking areas.
A VGC spokesperson confirmed the charging robot is still a prototype -- a press release from December 2020 noted one of the prerequisites for market maturity is Car-to-X communication to facilitate 'utonomous charging process.
“A ubiquitous charging infrastructure is and remains a key factor in the success of electric mobility,” VGC CEO Thomas Schmall said in the release. “Our charging robot is just one of several approaches but is undoubtedly one of the most visionary.”
Tim Urquhart, a principal automotive analyst at IHS Markit, said the development of such a device could be especially useful for EV owners who have space at home but may live far from public charging stations.
“One of my problems is there doesn’t seem to be much joined-up thinking between automakers and other players as to how they will get their vehicles charged,” he said. “This could also work in urban car parks and in urban environments, so there is a huge amount of potential, but commercialization and scale are the sticking points.”
That means automakers will have to buy into the concept and accept the extra cost in installing the charging component.
“That’s something they will have to negotiate, and this will probably start with premium brands before working its way down to more mass market vehicles,” Urquhart said. “It looks like [CES’ device] is a more cost-effective solution than the VW concept at least.”
He called VW’s idea a potential longer term solution for AVs entering self-parking facilities, where presumably the docking station will be able to connect to the vehicle.
“Then you will wind up with problem-free charging, which is what we all want,” he said. “For now, this is a really good step forward for vehicle electrification.”