Porsche is developing new EV charging technology that would see rapid charging for around 250 miles (400km) available in less than 20 minutes. This infrastructure is considered essential for long-range EV use, and with the Porsche Mission E due in the next few years, the Stuttgart company is aiming to address a lack of current rapid charging capability for this sort of car.
An 800 volt charging system is currently being focused on, which allows for a dramatically faster rapid charge than current systems allow. Most DC rapid chargers are rated at around 400 volts for a 50kW output – though Tesla’s Superchargers provide around 120kW but still at around 400 volts.This sees Porsche quote figures of 400km of charge in 19 minutes from a 220kW rapid charger. The biggest hurdle in implementing an 800 volt charging infrastructure though is technology. To double the voltage would see a significant increase in the amount of heat generated through the components such as cable and plug.
To tackle this, cooled components are being developed so that they aren’t too bulky or heavy to be used by the public because of insulation needs.
All of this is being worked on to bring en-route EV charging down to a similar time to that of refueling a conventionally powered car. The concept is called Porsche Turbo Charging, and the company is basing its efforts on a long route – that from Berlin to Lindau, around 720 km (almost 450 miles).Porsche assumes that one refueling stop would be included in such a trip – which although wouldn’t be essential for many petrol and diesel cars starting with a full tank, it isn’t an unfair expectation since the trip will take more than five hours even without stopping.
Allowing for a 15 minute stop – pulling off the road, refueling, payment, and rejoining the route (though probably rounded up to allow for a bit of mingling and leg stretching) – this would see Berlin to Lindau covered in 5.5 hours in a petrol or diesel car.
Current EV rapid charging at 50kW would mean a long-range EV would take eight hours to complete the same trip with two rapid charges. Porsche’s 800V system would drop that down to six hours however, still with two stops for a rapid charge, but at a much shorter waiting time. Although still 10 per cent more than petrol or diesel cars, it is much closer to that time, and is considered close enough to persuade more car buyers to pick an EV.
Graphs courtesy of Porsche.