Special Report: Britain’s Ultra-Fast Charging Problem

The latest news from the world of electric motoring

Good morning and welcome back to The Fast Charge, the electric motoring newsletter. My name is Tom Riley.

There is no news content in today’s email. That’s because instead, I’ve focussed entirely on a special report into Britain’s rapid charging network. It’s taken me weeks to do a lot of the research for this so I hope it’s interesting!

Normal service resumes on Tuesday. Have a great bank holiday weekend!

Do drop me an email at tomrileylondon@gmail.com if you have any feedback, questions or comments.

Special report: Britain’s Ultra-Fast Charging Problem

About two weeks ago, I was on ZapMap plotting out a journey to Somerset looking for the locations of ultra-rapid charging stations. These are the chargers that typically will deliver between 100kW and 350kWh, depending on the operator.

But, whenever I found a charger and checked its comments, I started seeing a pattern of complaints from people about the rates they were getting. I decided to investigate what was going on, and here’s what I found out...


Ultra-rapid charging is still quite a novelty in the UK. According to ZapMap, there are just 957 of them across the country - and that’s devices, not actual locations which are probably in the low hundreds.

However, we can expect to see a lot more ultra-rapid charging points in the future. That’s because the government and car manufacturers see them as a key to unlocking further EV adoption.

Only this week, Britain’s energy regulator, Ofgem, announced it was investing £300m to help triple the number of ultra-rapid electric car charge points. They want to build 1,800 along motorways and a further 1,750 in towns.

The reason being is quite simple: nobody wants to spend over an hour at a service station topping up their car, they’d much rather do it in 20 minutes or less. And that’s what ultra-rapid chargers can do. 

This is why an increasing number of new EV models are built to accept more than 100kW into their battery. It’s purely so owners can arrive at a station and juice up in minutes. 

On the face of it, ultra-rapid charging looks like a golden goose for those worried about the switch to electric cars. But is it all it's cracked up to be?

“Not charging at 150kW only at 50kW.”

“Only charging at 71kW.. pretty poor for a 150kW charger!”

“Underwhelmed that it only provided 54kW to my car. A car capable of 76kW.”

“Didn’t make it over 30kW - shop staff seemed pretty embarrassed that it was advertised at 150kW”.

I found a huge number of complaints like these by EV owners about ultra-rapid charging sites. In isolation, you might be able to explain them away, but I felt it required a closer look. After all, ultra-rapid charging is the most expensive way to refill your battery with ions - some can cost nearly 70p per kWh!

Why are people getting lower charging rates?

As you might expect, offering 350kW from one plug requires a great deal of hardware and planning. According to some, they can cost tens of thousands of pounds to install - which is presumably why Ofgem have dipped into their purse.

Given all a motorist does is park up for a charge, I presumed that if there were any issues with the charge rates people were getting, it’s probably a hardware problem.

Shell, which operate a number of ultra-rapid charging points as part of their Recharge network, disagrees.

“Simply put, some customers drive vehicles that don’t allow ultra-fast charging,” a spokesperson told me. 

This was a view echoed by other charging operators.

“Charging speed is determined by the vehicle, not by the charger,” said a spokesperson for Ionity, a company that operate chargers capable of delivering 350kW. “Only in case of a defect charging station or a wrong parameter setting a limitation might be caused by the charger.”

It is a fair defence to make. Although more EVs on the road than ever before are capable of taking on high charge rates, there is still a lot that won’t. The popular Renault Zoe, for example, can only accept around 50kW speed into its battery.

However, there is evidence to suggest that even cars that are capable are not getting anywhere near their top charge rates.

Drivers being let down

One driver I spoke to explained how his car, an Audi e-tron, repeatedly only received 80kW of power from a BP Pulse charge point advertised as offering 175kW. This is despite the Audi being able to accept 150kW.

The slowness of the charger meant that the time it took to charge his EV was almost doubled. “With young children waiting... every minute matters,” they shared online.

When I asked why he thought it might be so slow, he told me: “My hypothesis is that the chargers are deliberately rate limited.”

Could this be happening?

I asked Tom Callow, BP Pulse’s Head of External Affairs. Much like the other operators, Tom believes the issue is the car: “Our ultra-fast chargers are installed with the ability to output at their advertised rate, should the EV be able to accept that speed.”

He further defended BP’s chargers saying. “We do not share power across chargers like Tesla do with most of their Superchargers, for example, so that would not be the reason why a driver wasn’t getting the rate that they were expecting.”

The reason Tom believes could be the cause of most complaints is a lack of understanding about how charging a car works. 

“All EVs have an S-curve for their charging, typically starting out relatively slowly at their lowest state of charge (SOC) and then increasing to their maximum speed, before tailing off again at a higher SOC, usually beyond 80% or so,” explained Tom. 

Amongst the EV community, most people are familiar with the ‘state of charge’, however, given the 125% surge of new EV owners in the past year, perhaps the number that does is lessening. What may surprise a lot of people buying EVs advertised as capable of charging up in less than 20 minutes is… it might not strictly be true.

As Tom at BP summed up: “EVs will only hit their maximum charge rate for part of the charging cycle. So a car that is advertised as being able to charge at ‘up to 100kW’ may only hit this rate for a matter of seconds or minutes.”

Only being able to juice up at your top speed for ‘seconds or minutes’ is, in my mind at least, something that might shock a lot of people. 

A spokesperson for Ionity echoed this saying: “The expectation level of quite some customers regarding the charging speed turns out to be too high. Especially people who just started with EV driving often have the max charging speed for their EV in mind, assuming that this can be achieved along the whole charging process.”

Shell also agrees, but their hope is that: “Perhaps as the market grows, customers will become more acquainted with the principle that it’s always their vehicle that determines the max speed they are able to achieve.”

However, while all of this is interesting, these explanations still don’t fully answer why some people, like the Audi e-tron owner I mentioned earlier, are not getting anywhere near their top speed.

Based on the comments from BP, I suggested to the owner that it might be the car that is lowering the speed itself. They weren’t having any of it and pointed out to me their charging curve.

What’s a charging curve?

Now, a charging curve is what every electric vehicle has. It essentially plots what the maximum speed you can receive is versus your battery capacity. Typically, most empty batteries can accept a very high rate of charge. However, it tends to tail off after you reach 80%, this is to protect the battery.

It’s people’s charging curves that BP, Ionity and Shell were all referring to when they were speaking about a lack of understanding. A lot of EV owners probably have never even looked at their charging curve - they certainly aren’t advertised well (or at all) by manufacturers or dealers. This can mean many consumers might expect their ‘top rate’ all the time.

However, the Audi e-tron’s charging curve is quite a lot different to other EV’s. If you compare it to other vehicles, it’s pretty much flat at around 150kW until it reaches 80%. Essentially, if the power is there - which it should be at an ultra-rapid charging point - the Audi will take it. Nevertheless, the Audi owner only got 80kW.

This isn’t just an isolated example. A lot of complaints I’ve found come from owners who are in the same boat - driving an ultra-rapid capable EV but getting ultra-slow charges.


One reason many EV drivers believe they get less charge is if the station is busy. Essentially, the more people charging up alongside you, the less electricity is available.

BP, Shell and Ionity all told me that they worked to guarantee the rates they advertise from energy suppliers. This is perhaps made easier for them because they run smaller sites. Aka. locations where there might be 2 or 4 chargers. But what about larger ultra-rapid charging sites where there are 6 or more? Like the ones the government wants to see across the country.

Well, there are actually only a few like this in the UK to date. The most prominent is the brand spanking new charging spot at Rugby’s M6 Services. It is currently the largest ultra-rapid charging site on the motorway network. There are 24 available which offer up to 350kW of charge.

However, there are rumblings that the site, which contains 12 Tesla and 12 Electric Highway chargers, might employ power-sharing. 

One Jaguar I-Pace owner who visited the Rugby site a few weeks ago reported only receiving 32kW, despite the Jaguar being capable of taking well over 100kW. The motorist snapped a photo and explained “nearly all 24 units taken.”

Likewise, a Polestar 2 owner wrote on the SpeakEV forum of his visit: “All chargers occupied apart from two which were out of service. One car pulled out as we arrived. Free vend has finished and no one seems able to get over 50kW.”

If motorway sites like this do share power, as more people switch to EVs, it’s likely people could have to wait around longer than they first thought.

While it’s well known Tesla superchargers do share power, not so much is known about Gridserve - the company that own half of the Rugby site chargers along with Ecotricity.

When asked to comment, Gridserve did not respond to questions about power-sharing. However, like other operators, they explained: “Ultimately the car dictates the charging speed.”

Gridserve also said: “The likelihood is most drivers will be arriving with much higher SOCs and as such will never reach the cars theoretical maximum.”

Blame the weather

If it’s not power-sharing, what other reasons could be causing people’s vehicles to limit their charge?

Shell told me when they had investigated customer complaints about lower speed charging, there were some common themes.

“In most cases, the speed is affected by vehicle conditions – state of battery and weather temperature. In cooler weather and when the battery is closer to being full, the speed tends to be slower,” explained Shell. “In some cases, the speed wasn’t achieved due to missing firmware updates on the vehicle, or charge post side.”

There are two reasons given here. Firstly, the weather. Could it be that Britain’s largely cooler temperatures are stopping cars from reaching their full potential? It’s certainly a possibility, especially as other than heating and cooling your battery up, there’s little anyone can do to alter British weather, regrettably. 

The second reason is a lack of software updates. Given how connected EVs are today and will get in the future, software is increasingly important to the running of your car. Only last week, it was revealed that a software update from Tesla in Norway led to lower ranges in their vehicles and slower charging rates. They have now been fined and have to pay £11,500 to each driver impacted. 

Perhaps the entrance of tech titans like Apple to the car scene won’t be so easy.


I’ve spent acres of time looking into this and I still have a lot of questions. While there are many reasons why an EV might not hit their maximum charge rate, none seem to cut mustard with those I’ve spoken to.

“They're making a really big thing of the ultra-fast charging,” said the Audi e-tron owner. “But I feel cheated when paying £0.42 per kWh, but still problems starting a charge and only 80kW instead of 150kW advertised,” they added.

The Advertising Standards Authority state that no company can use “obvious exaggerations ("puffery") and claims that the average consumer who sees the advertisement is unlikely to take literally are allowed provided they do not materially mislead.”

I don’t believe anything that manufacturers or charging operators are doing is illegal. However, I do think there is a knowledge gap that is leaving a lot of consumers very frustrated. And, from what I’ve seen, claims by manufacturers, in particular, are not helping.

Obviously, everyone buying an EV should investigate it closely before doing so. But it strikes me that carmakers need to be a lot clearer on how their vehicles actually charge up. If someone realised they will likely only get 100kW of rapid charging for a few minutes, they might think twice about buying.

The German Automotive Consultancy P3 Group agree, in a report shared last year they state: “Charging power is not a sufficient indicator for the charging performance of electric vehicles.”

As the UK adopts more EVs, we cannot end up with a raft of people getting caught out

Operators and the government also have a responsibility to ensure that the hundreds of millions of pounds going into building ultra-rapid charging will last. That means mandating 24/7 maintenance, keeping its software updated and ensuring power-sharing is not utilised as a cheaper option - it will not help people long-term.

Going forward, I hope others look at this subject in more detail. It needs to be monitored and currently, it isn’t.

By Tom Riley

Many thanks to Shell, BP, Ionity, EVA England and the great EV community for being so helpful.

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