Rapid charging of plug-in electric vehicles

Technological dead end or a challenge to be overcome?

When screening the data sheets of prototypes electric vehicles and electric vehicle batteries, you often come across some spectacular recharging speeds. The 35 kWh lithium-ion batteries of Altair Nanotechnologies for instance are said to fully charge in a mere ten minutes.

What the data sheets don’t say is that the electric connection must be capable of supplying sufficient power for this rapid recharging. Only ten minutes for 35 kWh? That would require a 250 kW connection. This is about 20 times the maximum power of a residential connection. Consequently, rapid charging would be impossible at home. Moreover, it would create a serious challenge for any grid connections for electric recharging stations located along the road.

Several studies have asserted that a large penetration of plug-in electric vehicles is feasible without massive investments in new power generation and transmission infrastructure. But that is only true if those vehicles recharge at slow speed during the night, when there is sufficient idle generation and transmission capacity.

Imagine a scenario where recharging stations are built along the highway and can simultaneously recharge twenty vehicles with 35 kWh batteries in ten minutes time. A single such station would require a 5,000 kW connection. If those stations need to be built at regular intervals along all of our roads, it will require an entirely new dedicated electricity grid.

That is why some experts, like Andrew Burke, an electric vehicle engineering pioneer at the University of California, see the rapid charging of plug-ins as a technological dead end. Others, like Alan Gotcher, CEO of Altair Nanotechnologies, see those barriers merely as challenges that need to be overcome. Watch this space to see which of these two visions prove right.