Charge Points

Electric Vehicle Supply Equipment (EVSE) encompasses the conductors, plugs, devices, power outlets and apparatuses installed specifically for the purpose of delivering energy from the grid to an EV. The equipment also allows communication between the charging apparatus and the EV.

An Electric Vehicle charge point is classed as EVSE. There are various names for such equipment including charging post, charging point and charging station. Charging point or charge point is sometimes used to describe a single socket rather than equipment possessing multiple sockets. It is therefore important to highlight the following definitions that UK EVSE proposes the industry utilises:

EV charge point/charging unit – a single upstand or wall-mounted structure offering one or more socket outlets or tethered plugs suitable for charging EVs.

EV charging station – a physical site with at least one charge point installed suitable for charging at least two EVs. A station usually (but not always) has other physical structures accompanying the charge point(s) such as an energy supply enclosure (feeder pillar), weather shelter, signage, protection barriers for the equipment.

An EV charge point can be either wall or ground mounted and may provide AC and/or DC power at various power outputs utilising one or more of the five different charging plug or socket standards available on the UK market (please see below and our charge point procurement guide for more details here).

 


Charge point power output and charging speed nomenclature

There are currently a number of different names for the different charging speeds commonly used within the EV industry. These include; standard, fast and rapid and typically indicate a range of power outputs and charging times for a typical 24kWh EV battery.


Standard charging

Standard charging is what an EV user would recognise as plugging into a typical AC single phase ring main circuit using an EV cable with an infrastructure end plug that is commonly used in the household (i.e. a three pin BS1363 plug). The power output is therefore limited to the rating of the BS1363 plug at about 3kW. EVSE for standard charging is typically down-rated to only draw 10 Amps from a standard garage radial circuit which equates to about 2.4kW. The typical charging cable for standard charging possesses a three pin plug at the infrastructure end with a Mode 2 device (electronics block; see EN61851-1) no more than 30cm from the infrastructure plug. This Mode 2 device takes care of the communication requirement to initiate charging an EV. The other end of the cable possesses the correct plug to connect to the vehicle. This is usually one of either the five pin J1772 or seven pin Type 2 plugs (see EN62196-2). Standard charging infrastructure-side plug variations may include the EN60309-1 blue Commando connector which is more suited to outdoor use and is rated to 16 Amps equating to about 3.6kW. The power level drawn via the Commando cable variant will be determined by the Mode 2 device and is still likely to be 10 Amps. However, vehicle manufacturers are introducing Mode 2 devices and dashboard controls that allow the current drawn to be varied by the user (within the limitations of the circuit that the charging cable is attached to).

The typical standard charging time for replenishing a 24kWh EV battery from 0-100% State Of Charge (SOC) is eight to twelve hours. This depends on the efficiency of the conversion of AC to DC power by the vehicle onboard converter (the battery is DC) and the power down-rating of the Mode 2 device. For example; a vehicle onboard AC to DC converter with 85% efficiency and a power input of 2.4kW will take approximately twelve hours to charge a 24kWh battery.


Fast Charging

Fast charging is typically charging from a charge point socket or tethered plug capable of delivering 7kW or 22kW power output at 32 Amps single phase AC. However, it may also encompass home charging from a dedicated EV home charger that provides 3.6kW power output at 16 Amps single phase AC.

A fast home charger is typically garage wall mounted, possesses a tethered J1772 plug, Type 2 plug or Type 2 socket (whichever is compatible with the vehicle) and is supplied from a dedicated 16 or 32 Amp radial AC circuit from the home power supply. 3.6kW or 7kW output home chargers will usually fully charge a 24kWh battery in six or four hours, respectively. The actual time charging will depend on the efficiency of the vehicle AC to DC converter. The home charger communicates with the EV via the charging cable to initiate charging. This is termed Mode 3 charging (see EN61851-1). There is no Mode 2 device in the cable assembly.

A fast charging unit typically found at a workplace or on-street location will possess Type 2 seven pin sockets and provide 3.6kW, 7kW, 11kW or 22kW power output at 16 or 32 Amps single or three phase AC. The charging cable is carried in the EV and its rating is matched to the EV’s onboard AC to DC converter. A detachable EV charging cable suitable for use with a fast charge point usually has a Type 2 plug on the infrastructure end and either a Type 2 or a J1772 plug on the vehicle end (depending on the vehicle). Mode 3 communication takes place between the vehicle and the charge point (via the cable) in order to initiate charging. There is no Mode 2 device in the cable assembly. Fast charging from a 7kW, 11kW or 22kW socket to a vehicle with a 24kWh battery that has a suitably rated 7kWor 22kW onboard charger AC to DC converter will take approximately four, two or one hour(s), respectively. The actual time charging will depend upon the efficiency of the onboard AC to DC converter. Please note that cables with a lower power rating than the charge point and the EV will cause charging to take place at the cable’s rated current carrying capacity and will increase the time charging.


Rapid/Quick charging

Rapid charging (also termed quick charging) is typically from a charge point with tethered plugs that can provide a significantly higher power output than both fast and standard charging and can generally charge an EV to 100% SOC in an hour or less.

AC three phase rapid charging is typically at 43kW power output (at 63 Amps per phase from a three phase AC supply) utilising a tethered Type 2 plug attached to a charge point that resembles a forecourt petrol pump. The EV charg epoint communicates with the vehicle via Mode 3 before initiating a charge. 43kW units will charge a 24kWh battery to 80% in about 30 minutes. The vehicle onboard AC to DC converter (separate or integral to the motor) must be capable of accepting the higher level of charge. Some vehicles are fitted with such a converter as standard, others offer it as an option and some only accept DC rapid charging.

DC rapid charging currently (2013) provides 20kW, 44kW, 48kW or 50kW power output. The charging unit possesses the power electronics to convert AC to DC current at the correct level for the vehicle traction battery (as opposed to the vehicle onboard AC to DC converter used in AC standard, AC fast or AC rapid charging). The unit’s tethered plug is typically a CHAdeMO Association standard compliant JARI JEVS/G105 plug (see CHAdeMO Association). Communication between the charge point and the vehicle takes place by Mode 4 (see EN61851-1) before charging commences. A 50kW output unit can charge an EV (with a 24kWh battery) to 80% in approximately 30 minutes. A 20kW unit will provide an 80% charge in an hour. Charging from 80% to 100% typically takes around 30 minutes from a 50kW unit or slightly longer from a 20kW unit (most EV drivers do not charge to 100% at a rapid charger). In order to use a CHAdeMO charger the EV must have a JARI JEVS/G105 (CHAdeMO Association compliant) socket. Certain EVs possess the Combined Charging System (CCS or Combo 2) socket which is compatible with the DC Combo 2 tethered rapid charger plug. The vehicle Combo 2 socket is also compatible with a Type 2 plug. Charging using the Type 2 plug socket is AC at whatever power the vehicle onboard charger AC to DC converter can handle (usually 7kW; fast charging). Rapid charging using a Combo 2 plug enabled unit typically delivers the same power range as a CHAdeMO charger and therefore charges an EV battery to 80% in 30 minutes from a 50kW unit. Please note that the Combo 2 plug is rated to deliver much higher power levels up to about 90kW and communicates with the vehicle and the grid (where possible) utilising Power Line Communications (PLC; see ISO15118-1).