Public charge points deliver just 37% of advertised speed

Electric vehicle drivers who use public charging points are achieving as little as 37% of the maximum charging speed promised, according to research by What Car?.

The media brand took a variety of cars to 15 EV charging stations – operated by five different networks – across England to fund out how the speed a vehicle can charge varied  in the real-world.

At eight of the sites, chargers delivered power at less than two-thirds of the stated maximum rate, while just two achieved the advertised speed.

These results could have a critical knock-on effect for fleets as the drop-off in real-word speed compared to the advertised rate could mean that it takes longer for a vehicle to charge than expected – a key consideration for organisations, which look to optimise the efficiency of their operations.

Claire Evans, consumer editor at What Car?, said: “Our results highlight the fact that it’s almost impossible to predict how fast a car will charge up at a public charging point.

“The Government needs to make it mandatory for both the charging companies and car makers to provide EV owners with information on the charging speeds they should be getting.

“Charging companies should also be compelled to publish average charging speed data so EV owners can see which sites are providing charging at the expected rates.”

There are a number of factors which affect the rate of charge at charge points, including the maximum speed of the onboard charger on the vehicle, issues with the vehicle or charge point, the wider electrical infrastructure and the ambient temperature.

Vehicles also restrict the amount of charge they accept from a charger in line with parameters set by its ‘charging curve’, which prevents the battery from overheating,.

This was taken into account by What Car?, which only measured the charge speed delivered against the rate the car should accept at any state of charge.

With this in mind, the poorest performance seen was at an InstaVolt charger in Twickenham, Middlesex.

The advertised maximum charging rate was 125kW, but while the Renault Scenic test car is capable of accepting this much electricity when its battery is at 4% capacity, the charger delivered just 48kW – 37% of the figure stated.

A Peugeot e-208, which has a 98kW onboard charger, topped out at just 48kW (49%) at a Shell Recharge charge point in Tytherington, near Macclesfield, which had a stated maximum of 150kW.

Not all sites delivered slower charging than advertised, however. Two Fastned sites in Basildon, Essex, and St Albans, Hertfordshire, both provided power at 100% of the expected rate for a Vauxhall Astra Electric hatchback.

Meanwhile, an InstaVolt charger in Bromley, Kent, gave a Vauxhall Astra Sports Tourer a top speed of 98kW.