electric cars

Fast charging is already making it possible to work miracles on current electric vehicles. But beware, the future promises even more spectacular technical advances concerning the charging time of electric cars.

At the end of the last century, the few electric cars on the market could not even travel 100 kilometers with their very low capacity batteries. Equipped with ridiculously powerful engines, they required waiting very long hours on an AC outlet to be recharged. Of course, with modern electric cars, we have to show a little more patience to fill the latest generation batteries on a conventional 230-volt outlet. But in addition to compatibility with much faster and more efficient domestic systems, today’s electric vehicles also take advantage of new technologies delivering direct current to drastically reduce recharging time at special terminals.

Public electric charging stations: Up to 350 kW for the moment …

Because in recent months, operators have been deploying 350 kW public fast-charging stations. An unprecedented level of power for the electric automobile industry limited a few years ago to less than 50 kW. A modern city car like the Peugeot e-208, for example, can recharge its 50 kWh batteries to 80% in less than half an hour with a maximum charging power of 100 kW. A Porsche Taycan, equipped with a powerful 93.4 kWh battery, can be charged in just as little time as 80% by accepting a charging power of 270 kW. Today, most consumer models are generally limited to just under 100 kW. This limitation linked to batteries, therefore, comes from the car manufacturer, and not from the electricity operator: for the moment, no one has mass-produced electric cars capable of accepting more power to further reduce the time of charge without risking the reliability of their batteries, but the charging stations are already there!

And why not 600 kW?

The more car batteries gain incapacity, the more power must be increased to meet this famous promise of recharging the batteries to 80% in less than half an hour. However, some imminent novelties could be equipped with batteries of the size never seen before: the all-new Tesla Model S Plaid +, for example, carries batteries of colossal capacity. The American manufacturer refuses for the moment to communicate a figure on the subject, but this capacity is probably approaching 200 kWh given the maximum autonomy announced (more than 840 km!). Because yes, the more the batteries of electric cars grow, the more autonomy increases. Except that a 200 kWh battery would require more than 500 kW of power to recharge to 80% in twenty minutes. This is why manufacturers and operators are working in the laboratory on new systems allowing the use of current at even higher powers, and thus reducing the charging time of electric vehicles. Tesla is secretly preparing vehicles compatible with a fast charge at 600 kW. In China, charging protocols using even higher power and voltage are also being tested.

What profile for the electric car of the future?

So how far will the technology of automotive fast charge in the future? Researchers are already drawing the contours of the technology of the future: machines capable of recharging huge batteries to 80% in less than half an hour, thanks to sharply increasing charging power and voltage. The profile of cars will also change. While mainstream models will likely be limited to batteries with a capacity of 60 or 70 kWh, the more sophisticated or “premium” models will go well beyond this figure. More than 200 kWh? Probably.

Other technological revolutions?

What if battery technology allowed other big, spectacular advances? At EDF R&D, we now know that certain experiments allow battery cells to be recharged in a few minutes. But for now, these batteries are still much too heavy and expensive to end up in series in a car. This is why specialists believe that the maximum speed of charging should hardly change in the near future: cars will have increasingly larger batteries, compatible with increasingly powerful rapid charging devices. It will therefore become possible to refuel in about twenty minutes, regardless of the size of its battery. This is the most important thing because with batteries at 200 kWh, a fast charge at very high power would make it possible to recover more than 600 kilometers of range in less than half an hour!

Fast charging stations: An adapted deployment

Operators are also closely studying the behavior of new users of electric cars. Most of these users mainly charge the vehicle at home and only use the fast-charging stations on longer, more occasional trips. This is why it will be important to adapt the charging infrastructure during peaks in motorway traffic, for example during the summer holidays when many motorists cross France at the same time. And what about mobile fast-charging stations, which would be deployed on a temporary basis to cope with exceptional traffic on fast-charging networks: all the relevant solutions are on the table and understudy!