Recharging your electric vehicle can be quite confusing. The range of options almost feels like the infamous war between VHS and Betamax for videocassette tape format dominance. Except that it’s worse, with multiple connectors both around the world and within different countries, lots of different power levels offering a variety of charge rates, and umpteen services with different billing regimes. Then there’s home versus public charging to throw into the mix as well. In this first of a series of WhichEV guides, we look at the different plug types you are likely to encounter, what level of charging can be obtained from each one, and what that might mean for how long it takes to replenish your EV’s battery.
Electrical Current and Plug Types
The first thing to bear in mind is that EVs can be charged with AC (alternating current) or DC (direct current). Virtually all EVs support some form of AC charging, and the majority now offer DC charging, which is used for most of the faster charging rates (of which more in the next section). But there are still PHEVs that don’t have large enough batteries to warrant fast DC charging, so they just stick with AC.
Broadly speaking, there are plug types for AC and plug types for DC, but there is overlap so that a car only has to have one plug on board, with either the same plug supporting both AC and DC or a combo that integrates both options. However, some do have more than one, such as the Mitsubishi Outlander PHEV. Just to be contrary, Tesla originally took a different route for its cars, because as an early mainstream player it forged its own route with a proprietary charging network. The Model 3 moved to a more standard connection strategy, at least in Europe, and you can have earlier Teslas retrofitted to match.
It’s also worth noting that the plug on one end of the charger cable may not be the same type as the one you plug into your car. This is obviously the case with home charging adapters meant to plug into a 13A wall socket, which will lead to an adapter that has the appropriate connector for your car on the other end. The cable may also lead to a plug that will be familiar to a caravan user, the trusty Commando plug, which is used for hooking a mobile home up to the site’s supply. It can support up to 480V and 800A but is more likely to be 240V and 16A or 32A, which will allow a higher power than standard home power sockets, up to 22kW.
You can also get cables that allow you to connect your car into a charger with a different output plug type, or adapters that convert between connectors. Here are the main EV plug types you will find in the UK, grouped around whether they are intended for AC or DC charging. China has its own connectors as well, but we’re going to ignore those so as not to be too confusing, since you won’t find them in the UK – at least not yet!
An electric vehicle with a very small battery like a bike might just have a simple kettle lead that connects straight to the 240V mains power supply, or more likely an adapter similar to one you might use with a laptop. But cars will require a heavier-duty connection that can support higher power throughput.
The Type 1 connection (aka SAE J1772) is one of the original plug types, and still found in earlier EVs, as well as in the US and Japan. It’s used by the first-generation Nissan Leaf EV and Mitsubishi Outlander PHEV, for example. There’s a related DC version called CCS, but that’s only in America. In AC form, the Type 1 connection is quite limited, with charging up to a mere 7kW supported.
By far the most common type of AC connection is now the Type 2, which can be found on PHEVs from Mercedes and BMW as well as lots of EVs, including some Teslas. In AC guise, the Type 2 can support rates from domestic 3kW up to 43kW. The latter was primarily used by Renault’s ZOE, and has been phased out on new cars, although the Tesla Model S also supports 43kW AC over Type 2. Tesla has adapted the Type 2 for DC usage as well, which leads us to the next section.
With AC realistically topping out at 22kW, DC is where the really fast charging is available. As we have just mentioned, Tesla adapted the Type 2 plug for DC, enabling it to charge up to 150kW with its DC Superchargers, and AC up to 43kW with standard Type 2 chargers that support this. In the US, Tesla has its own connector. But this was never brought to the EU.
Japanese manufacturers have created a DC connector called CHAdeMO, found in all but the earliest Nissan Leafs, the Kia Soul EV, Nissan e-NV200 van, Peugeot i-On, and others. It’s bi-directional, which is why the Vehicle-to-Grid trial from Octopus uses it exclusively, requiring a Nissan Leaf as well.
However, increasingly the most prevalent connection type, which we hope will eventually become the European standard, is CCS2. This is not the same the CCS1 connection found in the US, because this integrates Type 1 compatibility, whereas CCS2 integrates Type 2. The CCS2 plug is basically a Type 2 plug with two extra contacts underneath for DC support. It’s a neat solution, allowing one plug to support lots of different scenarios. The CCS2 connector is compatible with Type 2 AC charging and rapid DC charging, depending on the charger and cable used.
In Europe, Tesla switched over to the CSS2 port for the Model 3 and will retrofit it to other models for a fee. It also now supplies an adapter that allows its specialised Type 2 to connect to CCS2-based chargers. There are also adapters and conversion cables between connector types, with greater or lesser amounts of compatibility. We can hope for a future where all connectors are CSS2, but for now, you’re likely to have multiple plug types to contend with. So either you will need a selection of adapters or you should make sure you know what’s available on the charging stations you head for and ascertain they have what you need.
Slow, Fast and Rapid Charging Rates
If the plethora of plugs seems confusing, the range of charging rates is equally mind-bending, spanning from a couple of kilowatts all the way up to (currently) 350kW, with various important steps in between.
Slow chargers for domestic 13A usage start at around 2.3kW, which is still only as much power draw as a typical electric fire. This can range up to 3kW, which is the limit of a wall plug before the fuse will blow. The plug at the car end will be Type 1 or Type 2. The next step up for the home will be 6kW, but this requires a professional installation on a higher-amperage fuse like the circuit used for an electric cooker or shower. A lot of lamppost chargers also operate at this rate, which is usually more like 5.5kW than the headline 6kW. All of these types of charging will be AC.
A rung up from Slow is Fast charging, which will range from 7 to 22kW. These will usually be public installations, although 7kW is also possible at home. The 11kW and 22kW varieties may be found at workplaces but require three-phase AC power so you won’t be able to install them at home unless you live in an industrial unit. A Type 1 port will be limited to 7kW, but Type 2 supports all the way to 22kW. Tesla’s Destination Superchargers operate at 11kW or 22kW AC. There are also some 25kW DC chargers in the Fast category using CHAdeMO or CCS2 connections.
The fastest chargers are the Rapid ones. As we mentioned, there is one AC option in this category – 43kW using a Type 2 connection, which only the Renault Zoe and Teslas will use. Most CHAdeMO-equipped cars only provide 50kW DC support, although the latest Nissan Leaf and Mitsubishi Outlander PHEV claim up to 100kW. But CHAdeMO 2.0 operating at 1000V and 400A will be able to offer 400kW charging. This may not come to Europe, because CCS2 can provide DC charging from 50kW to 350kW (with Ionity’s network) already, and is increasingly becoming the standard.
Anything at 100kW or above is classified as Ultra-Rapid, however, and this includes Tesla’s Supercharger network, with V2 installations offering 150kW and V3 up to 250kW. According to Zap-Map, there were only 896 Ultra-Rapids in the whole of the UK by the end of 2019, but 6,212 Rapids.
How high a rate your car can charge at depends on its specification. The power ceiling will be constrained by the car’s on-board transformer, because this will convert the AC or DC input into the DC voltage that the EV’s batteries and motors natively operate with. For example, the Audi e-tron 50 Quattro has a 11kW charger on board, whereas some earlier EVs and even current PHEVs have lower-power transformers, such as 3.7kW. There is a 22kW AC option for the e-tron too. An EV will also have a maximum DC charge rate. The Audi e-tron is one of the few EVs that can take advantage of Ionity’s 350kW DC capabilities, alongside the Porsche Taycan. The Tesla Model 3 can use the 250kW maximum of its V3 Superchargers, while the Model S and X have just been upgraded to 225kW. Many other EVs will be limited to 50kW DC charging.
How long will my car take to charge?
The quickest time your car takes to charge is a function of its usable battery size and the maximum charge rate it supports. Most of the time you won’t be charging at full speed, particularly at home. You also don’t get the full specified rate for the whole duration of the charge cycle. The 20-80% region will be quicker than the last 20%, and there’s a curve across the whole period.
However, the power of your charger will make a big difference to how quickly you can add miles to your battery. We’re going to base the following calculations on the Audi e-tron 55 Quattro because it has a huge 95kWh battery and supports the latest 350kW charging from Ionity, giving us a full range of examples. We’re also assuming the 22kW AC upgrade. Below are the approximate charging times to reach 80% from zero at various popular power levels. For the Slow and Fast rates, the figure is to 100%. These times can vary a lot with different vehicles, and Audi claims it has one of the best charging curves in the business thanks to clever battery cooling.
|Ultra-Rapid 350kW||Ultra-Rapid 150kW||Ultra-Rapid 100kW||Rapid 50kW||Fast 22kW||Fast 7kW||Slow 3kW|
|12 mins||30 mins||45 mins||1.5 hours||4 hours||13.5 hours||31 hours|
For a battery this big, the best 7kW home charging is still going to take longer than overnight, unless you’re a very lengthy sleeper. But a 350kW Ionity installation – assuming you can find one – will take the time for a quick coffee, while 100 or 150kW is still just a quick lunch stop. So not quite as fast as filling up a petrol tank, but perfectly viable if you choose the right kind of charger for the appropriate usage scenario and plan your journey accordingly.
You can’t just arrive at any charging point with any car and start using it. Most new rapid chargers now offer a card-based pay-as-you-go option, but this aspect is not like petrol stations, and is often more expensive than having a membership card. Tesla Superchargers are for Tesla owners only, and there is a plethora of networks, with a wide variety of membership types and payment plans. In our next instalment of this series we will be looking at the networks available, how much they cost, and which ones offer the best deals.