Guide to EV charging

Electric vehicle (EV) charging is an important aspect of EV ownership. With power rating, connector type, cabling requirements and vehicle specification to consider, Wessex Garages have created a step-by-step guide that cover the key issues related to EV charging.

EV charging explained

There are three main types of EV charging – rapid, fast, and slow. These represent the power outputs, and therefore charging speeds, available to charge an EV. Note that power is measured in kilowatts (kW).

Rapid chargers are the fastest way to charge an EV, and predominantly cover DC charging. This can be split into two categories – ultra-rapid and rapid. Ultra-rapid points can charge at 100+ kW – often 150 kW – and up to 350 kW, and are DC only. Conventional rapid points make up the majority of the UK’s rapid charging infrastructure and charge at 50 kW DC, with 43 kW AC rapid charging often also available.

Fast chargers include those which provide power from 7 kW to 22 kW, which typically fully charge an EV in 3-4 hours. The most common public charge point found in the UK is a 7 kW untethered Type 2 inlet, though tethered connectors are available too for both Type 1 and Type 2 connectors.

Slow units cover chargers rated between 3 kW to 6 kW and are best used for overnight charging, usually taking between 8-12 hours for a pure-EV, or 2-4 hours for a PHEV. Typically referred to as 3 kW points, slow chargers can be rated at up to 6 kW, with 5.5 kW commonplace for lamppost-based charge points, whilst three-pin plugs often charge at 2.3 kW. EVs charge on slow devices using a cable which connects the vehicle to a three-pin or Type 2 socket.

Charging on public networks

The UK has a large number of public EV charging networks, with some offering national coverage and others only found in specific regions. The major UK-wide networks include BP Chargemaster Polar, ubitricity, Ecotricity, Pod Point, Tesla, InstaVolt, and Charge Your Car.

Regional networks usually cover well defined areas such as London, Scotland, the Midlands, or the South West. Since a number of these are operated by or have links with national networks, it is often possible to use the points within these regional networks with a national account. However, the level of access depends on the network and specific charge point.

Payment and access methods across networks vary, though all public points need to offer ad-hoc access. Most networks offer access via an app or RFID card (or both), while web access is also common. Contactless bank card access is becoming increasingly common, particularly on rapid charge points, requiring no prior registration or account set up.

Although a number of EV charge points are free to use, the majority of fast and rapid chargers require payment. Charging tariffs tend to comprise a cost per energy consumed (pence per kWh), though a price per charging time (pence per hour) may be found, or a set fee for a charging session.

How to charge an EV at home

Charging at home is often the most convenient and cost-effective way to recharge an EV. Government grants are available for the installation of home EV charge points, and a large number of companies offer a fully installed charge point for a fixed price.

Most home chargers are either rated at 3 kW or 7 kW. The higher powered wall-mounted units normally cost more than the slower 3 kW option, and can halve the time required to fully charge an EV, depending on model. Many plug-in car manufacturers have deals or partnerships with charge point suppliers, and in some cases provide a free home charge point as part of a new car purchase.

In most cases, home-based charging requires off-street parking to avoid trailing cables across public footpaths and public areas. While less common, on-street residential charging units are becoming available, particularly in urban areas.

How to charge an EV at work

An increasing number of companies are installing workplace EV charging units for use by employees and visitors. As with home-based charging, plugging-in an EV at the workplace charging makes sense, as an employee’s vehicle will typically be stationary for most of the day when it can be conveniently charged. Work-based chargers can also play a role in attracting customers to visit a commercial or retail site.

While workplace charge points are similar to home-based units, power-ratings tend to be higher with more 7 kW and 22 kW units installed. Many business units feature a double socket, allowing them to charge two cars at the same time. The higher power units also enable plug-in company fleets to ‘opportunity’ charge in the middle of the day to increase the effective number of business miles driven per day without having to use more expensive charging on the public rapid network.

Company benefits in the form of grants and enhanced capital allowances are available for workplace charging units. Company owners can decide whether to provide free charging or charge a fee to use the facilities, many opting for zero or low cost to incentive EV usage within the company and by customers and visitors.

Charging your electric car

Electric vehicles have set inlets, which require specialist connectors to plug them in. These are often covered by the cables provided with the car, and allow for charging on slow and fast chargers across the UK. Rapid charging uses connectors tethered to the charger, so drivers don’t need to carry around cables to cover this charging type.

Most new EVs will use the Type 2 standard for charging, with a Type 2 CCS inlet fitted to allow rapid charging. This is fast becoming the most common charging standard, with the Type 1 inlet found predominantly on older models. Rapid charging is split between CHAdeMO and CCS standards, again with the latter becoming increasingly popular. However, considering the two biggest selling plug-in vehicles in the UK use CHAdeMO inlets, it will take longer for the switch-over to take place.

What many potential EV buyers don’t realise is that cars allow charging at different rates. There are on-board chargers or maximum charging rates accepted, which mean that for example, whilst you can plug in a car that can charge at 7 kW to a 22 kW charge point, it will still only draw a maximum of 7 kW. Many plug-in hybrids are unable to rapid charge too, and EVs will offer different rapid capabilities depending on model.