Sion solar car prototype shows how it can charge other electric vehicles

The Sion solar car, that is being billed by start-up Sono Motors as the solar car “you can really afford“, will not only be able to harvest energy directly from the sun thanks to solar cells integrated into its body, it will also be able to charge other electric cars.

Sporting a 35kWh battery and up to 255km driving range, according to the WLTP standard, Sono Motors says the Sion can also generate up to 35km driving range solely from its integrated solar cells.

But the inclusion of two-way charging turns vehicles that have this capability from simply a transport device in to, quite literally, a “battery on wheels”.

Known as “bidirectional charging” it is already possible to use energy stored in EV batteries such as the Nissan Leaf and Mitsubishi Outlander PHEV (plug-in hybrid), and put that into the grid or home.

But the important difference with the Sion is that instead of using the CHAdeMO plug standard favoured by the Japanese carmakers, it uses two AC Type 2 connectors.

We first heard that two-way charging using CCS2 plugs would become possible at the unveiling of the Nissan Ariya, which is the Japanese carmaker’s second electric vehicle and its first to use CCS.

But while CHAdeMO was originally developed with bidirectional charging, it is not winning the “plug war” as documented by Bryce Gaton here.

Instead, carmakers are turning to CCS2, which combines CCS DC charging with the Type 2 AC charging plug.

Sion, however, has taken the step of integrating two-way charging by using an AC Type 2 plug and a Type 2 port.

Sion shared an image (above) of its approach to this in a blog post in December but did not give much insight into it at the time, only saying that, “One central component of this is the onboard charger, i.e. the device to which all high-voltage components of the vehicle are connected.

“These include, for example, the high-voltage battery that drives the vehicle and the high-voltage air-conditioning compressor that compresses the refrigerant for the air-conditioning circuit.”

Which brings us to the moment in the Sono Motors video (embedded below), in which Sono co-founder Laurin Hahn explains how the AC two-way charging will work.

At around 6:15 into the video, he lifts the charging port cover to reveal not one port, but two.

“Here I charge the car, here is CCS and here is Type 2,” Hahn says.

“And here I just have the Type 2 the other way around, so I can charge another electric car.”

Lifting the bonnet, Hahn goes on to show the on-board charger which controls all the vehicle’s charging.

“Well it’s in there, it even has B-sample status – that’s relatively close to the series,” he says.

“And internally we call it OBC, on-board charger, and it can already charge bidirectionally.

“Currently the car is in single-phase and we will increase it to three-phase for the test drives.”

The Sion will apparently be able to charge another electric car at a rate of up to 11kW.

This article has been updated to clarify that the Sion prototype uses AC, not DC, two-way charging.