Ever since the first Ford Model-T rolled off the production line in 1908, drivers have faced the same easy choice about how to power their vehicles: petrol or diesel? But electric vehicles (EVs) are introducing new levels of complexity to the decision—with a seemingly bewildering array of charger types now available to power the world’s fast-growing green fleet.
This article looks at the different EV charger types and uses cases to find out which will rule the UK’s growing home market. We’ll also look at capacity, charge time and varying features that EV and infrastructure designers should consider when steering the UK’s drive towards greener transport.
The most significant variable at play with EV charge points is the kW rating. For EV drivers, this translates to an all-important metric: The time it takes to reach a full charge. Charge points are generally rated from level 1-3 according to their speed-to-charge and kW rating, with level-4 negawatt ‘megachargers’ for commercial E-HGVs currently in development but not yet widely available. Rated at just 3kW, level-1 chargers on the public network found on the UK’s streets take around 10-14 hours to fully charge an EV, while newer level-3 350kW ultra-chargers take a lightning-quick half hour.
There are several types of connectors with which to connect EVs to chargers. Older type-1 connectors have been gradually phased out in favour of the newer Type-2 and CHAdeMO connectors, which offer rapid and ultra-rapid charging capabilities. And charge points can give either tethered charging through a cable attached to the unit, like a petrol hose to a pump, or untethered charging via a discrete cable.
With so many variables at work, it’s little wonder the cost of EV charging systems and charge point production and installation also vary widely, according to complexity, kW capacity and more.
Slow chargers are the UK’s second most popular type of charge point after fast chargers. In this class, you’ll find the three-pin chargers commonly seen on lampposts and so-called granny chargers—a cable that connects EVs to a standard UK plug socket.
The RAC recommends using level-1 slow chargers only in emergencies when no other power source is available. The wide availability of relatively cheap cables for charging via a mains socket in a pinch means granny chargers will remain a popular option for home-charging at least until faster charge points become more widespread.
Rating and charge time
Level-1 slow chargers are rated from 2.3 to 6kW and typically take around 10-14 hours to reach a full charge.
Cost
Installation costs vary but expect to pay from £650-£1250 with no additional fuse circuitry required to connect to the UK grid.
Tethered vs untethered charging
Slow chargers use an untethered cable type-2 connectors vehicle and charger-side.
Installation
Type-1 chargers require no additional circuitry to connect directly to the UK grid. They’re compact enough to be concealed in a lamp post.
Availability and vehicle compatibility
Connection comes in the form of a standard three-prong household plug on one end and a seven-pin type-2 connector for the vehicle. Some older vehicles use the older 5-pin type-1 connectors.
There are now 7766 public slow chargers in the UK and most consumer and commercial EVs have slow charger compatibility.
Usage
Type-1 slow chargers are most commonly found in residential areas or the workplace.
Fast chargers are the UK’s most commonly found EV power source on the public network and in the home and workplace. Most offer 7kW of untethered charging, although some units offer 22kW. Tethered versions are available. Most EV drivers use a fast charger at home and top up using the UK’s growing network of rapid chargers at service or petrol stations.
Rating and charge time
A fast charger with a speed of 7.4kW will recharge an EV in around six to eight hours, while a 22kW commercial charger takes about three hours.
Tethered vs untethered
The majority of public fast chargers are untethered. Domestic units can be either tethered or untethered.
Cost
Level-2 fast chargers cost from around £300 to +£1500 to install. However, costs can rise if additional circuitry is needed.
Installation
Level-2 chargers may need additional circuitry to connect to the UK grid. Home units tend to be around the size of an electric shower, while public fast chargers are roughly the size of a parking metre.
Availability and vehicle compatibility
Most EVs and plug-in hybrid EVs have fast-charge capabilities, using a standard type-2 connector, although a handful of older EVs still use the older type-1 sockets. There are 18,856 fast chargers currently on the UK’s public network and most of the UK’s half a million EV owners have a fast charger installed at home.
Usage
Fast chargers are commonly found in the home and public spaces like car parks and supermarkets. Many newer workplaces also provide fast charging facilities, which are also the power source behind many commercial EV fleets.
With a rating of 43-50kW, direct current (DC) rapid chargers let EV owners recharge in around an hour. Ultra-rapid chargers, rated at 100-350kW, take around 40 minutes and next-generation 350kW speed chargers need only half an hour. Both rapid and ultra-rapid charge points are usually found at motorway service points.
Rating
Ratings of 43kW to 350kW provide a full charge in an hour or under
Cost
DC charging requires additional hardware or circuitry, so installation costs can vary.
Installation
Additional hardware and circuitry to connect DC chargers to the grid, and multiple tethered connections make rapid charger units larger than their slower counterparts—about the size of a fuel pump.
Tethered vs untethered charging
Both rapid and ultra-rapid chargers usually use tethered cables.
Usage
Find rapid and ultra-rapid chargers at motorway service stations, petrol stations and some supermarkets.
Availability and vehicle compatibility
Only newer EVs can handle rapid charging, and this is reflected in the relatively low numbers on the UK’s public network. According to the charge point locator app, Zap Map, there are just 4016 rapid and 1407 ultra-rapid chargers on the public network at the time of writing in March 2022.
New rapid infrastructure is being added daily and level-3 chargers will become a mainstay of the UK’s network as more commercial and domestic EV manufacturers incorporate rapid-charging compatibility. Level-3 chargers use a DC current, so they are not suited to home installation and aren’t found on private UK driveways.
While not yet commercially available, megachargers like those being developed by Tesla promise to deliver more than 1MW of charging for large batteries in E-HGVs and offer a tantalising glimpse into the future of long-range commercial EVs. Early images of megachargers show devices almost the size of a petrol station forecourt, and early prototypes add up to 400 miles of range with a half-hour charge.
By definition, every home in the UK is capable of charging an EV via a level-1 granny charger hooked directly to a mains socket. But with slow charge times of up to 14 hours, it’s no wonder dedicated they aren’t the preferred choice in the home.
On the public network, rapid and ultra-rapid charging capacity is increasing daily, but prohibitive DC requirements mean there is little chance of them becoming a feature of modern homes any time soon.
For the moment, level-2 fast chargers offer EV owners a perfect combination of relatively low installation costs, compact design and acceptable charging times. And this trifecta means there is no real competition for home-market leader status in the foreseeable future.
Dalroad’s team of independent engineers is ready to advise on your EV design or charge point challenge and connect you with the components to make it happen.
Contact us today to talk about your project.
