EV charging curves and why they are important
The latest news from the world of EVs
Hello and welcome back to The Fast Charge, a weekly British EV newsletter.
In today’s edition… grid capacity concerns, confident electricians, and new investors for British start-ups.
Elsewhere and further down… I wonder if we need to boost awareness of EV charging speeds to prevent queues and disappointment in the future.
As ever, if you have any thoughts or feedback, please do feel free to drop me a line at email@example.com or simply reply to this email.
In the last week…
BLACK OUT: Can the grid cope with the future electricity demand? If you listen to National Grid, the answer is yes. However, quite worryingly this past week, the Greater London Authority informed developers in West London that it could potentially take more than 10 years for the electricity grid to sustain new homes at Ealing, Hounslow and Hillingdon. David O’Leary, policy director at the Home Builders Federation, suggested the problem could become more widespread as we move to create net zero homes, such as installing EV chargers. Read more.
GRID FLEX: As pressure on the grid continues to rise, there will no doubt be an increasing focus and need for smarter EV charging - especially as unmanaged EV charging could add up to 20GW to peak electricity demand by the middle of the century. There have been various trials over the past 24 months to test demand flexibility in people’s homes. The home charger maker myenergi is one company getting involved. Last week they put a call out for existing customers to get involved. Read more.
NEW SURVEY: Speaking of electricians, a new survey of 500 wire wizards by City and Guilds found only 28% of electricians have undertaken specific EV charger training. Not that this is a barrier, as 73% of respondents said they were likely to seek work in installing or repairing EV charge points in the next 12 months. Read more.
SHELL SUIT: As part of its growing e-mobility agenda, Shell has licensed its name to a US manufacturer to produce an e-scooter and e-bike (the Shell Ride). The oil giant’s side hustle launched back in February. I’m not sure it’s available in the UK yet, should you have been keen on one. Read more.
SHELL PRICING: Closer to home, Shell recharge yesterday increased its pricing. The new rates will see ultra-rapids (150kW+) cost £0.65, up from £0.59. This is an 11% jump. Read more.
NEW FACILITY: As BP unveils its latest quarterly profits, which max out at £6.9bn, the oil giant revealed yesterday it would invest £50m in a new EV battery testing centre and analytical laboratory in the UK. According to BP, the new facilities will be open by the end of 2024 and located at their existing HQ for its Castrol business in Pangbourne, Berkshire. The centre will be used to further develop the fluids in batteries, so that they be charged quicker and improve efficency. Read more.
THREATENING MOVE: Toyota has said it will leave the UK if the government decides to ban hybrid cars from 2030, rather than the current 2035 deadline. Toyota, the Japanese carmaker, is infamous in the EV world for having flunked its position by instead pinning its hopes on hydrogen. The company has since had to backtrack, being criticised by large investors for its slow pace. I’m not sure what has prompted worry for Toyota, as I don’t believe there have been any rumours on moving the dates, but perhaps instead it’s just Toyota putting a marker down. Read more.
CONVERTED SUCCESS: The British EV classic car conversion business, Everatti, has gained Matt Rogers, co-founder of Nest and member of the team that created the original Apple iPhone, as a new investor. As well as converting classics like the Ford GT40 – which gets me very hot under the collar – the company is moving into commercial consulting. Aka, using its technology to help other companies convert EVs – which could be a big business in the future. Read more.
NEW INVESTMENT: On the topic of growth, UK-based EV subscription service, Onto, last week landed $60m of new investment in its Series C. The round was led by Legal & General. According to Onto, the money will “enable the business to consolidate leadership in the UK and expand into Europe, starting with Germany.” By consolidating leadership, one can presume that’s translated as weathering the economic uncertainty in the months ahead. Great news for a British start-up though. Read more.
E-RACING: At the weekend, I attended my first Formula E race. It was held at the Excel Centre in London. I’m a big F1 fan, so was keen to understand whether this version, which comes with no pitstops, each team getting the same battery hypercar, and Mario Kart style ‘attack mode’ boost corners, would be any good. Reader, it was. I shan’t bore you with my experience, only to encourage you to check it out next time it comes to the UK. It was quite reasonably priced and had plenty of entertainment. The only drawback was the laughable greenwashing throughout, such as the event being sponsored by SABIC, a company 70% owned by Saudi Aramco. But don’t worry, the beer came in an eco-cup. Sarcasm aside, it was stupendously fun.
RELIABLE CHARGERS: Last week, I published a table summarising how the 8 biggest rapid charging networks compare on reliability. As I mentioned, in my newsletter, the data was created by analysing publicly available information on Zap-Map. I fully acknowledge this information can change day-to-day, but it is the best indication we have right now of how charging networks are doing. In all the feedback I got, here are a couple of items of note. Firstly, it does seem like the charging networks with the older equipment are the ones doing worse. GeniePoint and BP Pulse, for example, started growing their networks many years before InstaVolt and Gridserve really got going. Although this excuse seems to fall away in the face of Tesla and its Supercharger network that has also existed rather unchanged for years. Secondly, in an upcoming interview on The EV Musings podcast, apparently GeniePoint’s Managing Director has acknowledged how poor their network is – a reminder, 1 in 4 had reported faults – and is currently repairing/replacing an average of 7 units per week.
VW SPOT: After reading about it and seeing models on YouTube all the time, this week I saw my first real-life ID Buzz (pictured below). I spotted it in Chiswick with German numberplates on, presumably heading to a nearby garage. It looks a lot better than I first imagined.
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EV charging curves and why they are important
When I first started writing this newsletter nearly two years ago, I spent much of my time in online forums talking to other people interested in EVs. Back then, most drivers were still early adopters and, as such, were often deeply enthusiastic, nerdy, and perhaps slightly obsessive.
However, since that time EVs have hit the mainstream, and I’m a little worried the knowledge sharing hasn’t kept up. And, therefore, an increasing number of new EV adopters may not understand the engineering of their cars as much as they might have their combustion engines.
In one area this is often a noticeable problem: battery charging speeds.
As anyone that’s watched an advert or review of an EV can testify, one feature often highlighted for prospective electric car buyers is how quickly it can be recharged. Statements like ‘can recharge to 80% in 20 minutes’ are often the go-to.
Now, while the reality of EV ownership is that you won’t use rapid charging nearly as much as you believe, how quickly models recharge is a key selling point for those new to this space.
But, as many long-time EV owners have taught me, these claims should be treated with caution by prospective buyers.
The state of charge
I’m sure I will be preaching to the converted with this one, but for those who are unaware; batteries do not simply get charged up at the same rate all the time. Every EV battery has a charging curve. This means that as your battery becomes topped up, the amount of power it accepts changes.
Each EV’s ‘charging curve’ is very different, with most hitting their max speed between 20% and 40% of the battery being charged up. The result is, though carmakers can boldly say their EV can be supercharged, this might not be for a very long time. And a new analysis by the consultancy P3 has reinforced this fact.
Take Porsche, for example, which proudly boasts of its Taycan GTS “even when charging, its 800-volt architecture produces charge power of up to 270kW. In as little as 4.5 minutes, the Taycan can be charged to add a range of up to 60 miles under optimum conditions.” The truth is, according to P3, the Taycan battery can only accept 270kWs for up to about 50% charge maximum, then it falls quickly to 150kW by 70% charge…. and then much lower beyond that.
It’s a similar story for other luxury vehicles P3 analysed, such as the Audi e-Tron, Mercedes EQS and BMW iX.
This is critical information consumers should have when buying an EV, if not just to manage their expectations out on the road.
The P3 consultancy, based in Germany, has already done much of the legwork on this topic. In their third ‘Charging Index’, published in mid-July, EV models are compared based on their battery capacities.
I know that sounds like a text-based sleeping pill, but it’s supremely interesting. The report contains the charging curves of various EVs versus their nearest competitors, though not for every EV on the road today. What is clear from the findings, however, is most cars do not hit their top charging speeds for long.
When I first touched on this subject last year, a spokesperson for BP Pulse told me this quite clearly saying: “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.”
This fact was reiterated by several other rapid charging operators including Ionity. At the time, a spokesperson told me: “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.”
Evidently, this is an important part of EV ownership. But, a year on and the concept of charging curves still seems rather unknown at a consumer level. If you Google ‘EV buying guides’, it is not often (or ever) something that comes up. Yet, you only have to quickly look online or get out on the road to see evidence of a knowledge gap.
As just one example of many, at a 120kW InstaVolt charger in East London, I was looking at recently, I saw one user complain it “takes a while to get going, and on the case, barely getting above 50kW after 6/7 minutes.” They uploaded an accompanying image suggesting their battery had started charging from about 40-50% capacity, often where most curves are significantly lower than their advertised rate.
The charging curve of an EV is evidently important for anyone thinking of buying one. It’s also information not easy to come by. Not once in any EV I’ve test driven – which is quite a lot now – has a company rep or dealer ever mentioned or offered this information freely.
Given EV ownership is now on its own exponential uptake curve, is it time that changes? Surely customers need to know what they are getting in for at the point of purchase.
Presently, much of the stick of low charging rates is often made at the networks. Even when I touched on this topic last year, I was convinced the networks might be hiding behind power issues. Alas, in pretty much all instances it’s the cars preventing charge. It’s noticeable that rapid charging networks like Fastned and Osprey host explainers on the limitations of charging speeds on their FAQ pages.
But there is another good reason for educating people on charging curves, and that’s to prevent queues at rapid hubs.
Limiting public devices
As more people use rapid hubs, it’s important that people know how best to use the devices. Yet, it is evident at increasingly busy public charging stations that some people don’t know, such as leaving their EVs plugged in until they are near 90 or 100% charged. And this is not a behaviour we want to be mass adopted.
The ideal rate people should recharge to on rapid public points is 80%, as beyond this every EV’s charging curve collapses, meaning it will take an extremely long time to charge that last 20%. Not doing so can cause blockages and queues at chargers.
I witnessed this only a couple of weeks ago when watching a stream by EV blogger Teslabjorn Live where he had to queue for 30 minutes at a motorway charging hub in Sweden. At the time, two of the devices had cars charging to 90% and above. This exacerbated wait times.
Either education on charging curves needs to become more widespread amongst new EV owners, or we may need to see other methods to prevent issues. This could include throttled pricing or overstay fees for those lingering past 80% on rapid chargers to guard against bad behaviours.
Whatever the case, the bottom line is that we need some change to stop problems down the road.
For more information:
Check out P3’s Charging Index here.
Read my report from last year on rapid charging here.
And shout-out to Jaan, who writes the EV Universe, for prompting me to the latest P3 report.
By Tom Riley
People tend to charge to 100%, due to the low availability of chargers. Better charge to the max ‘just to be on the safe side’, regardless of the extended charge time. I myself have done this when travelling to a holiday destination within the UK. If however, a charger had been available at the holiday cottage we were staying at, I would not if adopted this inefficient charging approach. In short, the proliferation of EV chargers will lessen the current need for many drivers to charge to 100%, but variable pricing based on the vehicles charging rate will be needed to manage Rapid charger throughout as EV uptake increases.
Inevitably, I believe that variable pricing will be introduced at Rapid chargers, to manage demand. As the charge rate diminishes, due to the car’s charging curve, the price will go up.