Science & technology
Pump up the voltage!
Electric vehicles which operate at 800v can be recharged in half the time
Electric vehicles (EVS) are becoming commoner. Some 750,000 of them were sold in the first quarter of 2021 according to JATO Dynamics, a British consultancy. JATO reckons EVS now account for just over 4% of new-car sales, up from 2% in the same quarter last year. Yet many potential buyers still suffer from "range anxiety", a wariness about having to interrupt a long journey while an EV's battery is recharged. The good news is that the time required to do this is about to be slashed.
Most EVS operate at 400 volts (400v). But a number of producers and their component suppliers are now gearing up to introduce 800v drive systems. Higher voltages supply the same amount of power with less current, which means electric cables can be made lighter—the consequent weight saving helping to increase a vehicle's range, says Christoph Gillen, a technology director for GKN Automotive, a British components group which recently announced that it is accelerating its development of 800v drive systems. As most cabling is made from copper, the price of which has been soaring, this should also save carmakers money.
What drivers are most likely to notice, though, according to Dr Gillen, is that vehicles with 800v drive systems will be able to make greater use of some of the latest fast chargers. For instance, Ionity, a German company backed by a number of carmakers, is building a network of 350kw fast chargers across Europe. These automatically optimise charging speed to the maximum that a vehicle can handle. Using one of these, an EV with an 800v system will be able to recharge about twice as quickly as a similar vehicle with a 400v system.
Fast chargers are also more efficient. All chargers take electricity from the grid, which uses an alternating current (AC). When an EV is plugged into a standard charging point, its systems convert AC into direct current (DC), which is what a battery needs to store electricity. Fast chargers bypass the vehicle's converter, using their own beefier bits of kit to pump a DC charge directly into the battery.