A guide to EV charging
Charging your Electric Vehicle is a vital part of ownership, but getting to know the different plug and inlet types can be confusing. This guide has been put together by the Drivenergy team to help make the process a little easier. It may seem confusing now, but if you buy or lease an EV you'll get the hang of it in no time.
Charging - the basics
Both EVs and Plug-in Hybrid Electric Vehicles (PHEV) have built-in batteries which need to be recharged from an external mains supply. The vehicles have inlets for connecting a charging cable, but they are not all the same. Vehicles may have two charging inlets; one for AC charging and one for DC, or these may be combined into one physical connection.
The vast majority of electrical grids around the world use Alternating Current (AC) to distribute power. UK and European homes are almost exclusively fed with AC power. Batteries use Direct Current (DC) so charging requires converting the AC power to DC power. AC electricity is used for 'slow' and 'fast' charging and DC is used for 'rapid' charging. These terms have become commonplace in the UK, but their meaning varies around the world (e.g. in Ireland and North America, 'fast' is used to mean 'rapid!').
Slow and Fast Charging (AC)
When AC electricity is used for charging, an onboard charger integrated into the vehicle converts the incoming AC to DC to be sent to the battery. AC charging occurs using one of two types of charging plug, simply known as Type 1 and Type 2.
The Type 2 charging plug
The Type 2 charging plug is a European standard (IEC 62196) for all new electric car models produced from 2017. The plug was designed in 2014 by MENNEKES, and so is commonly referred to as the MENNEKES plug.
The connector contains up to seven contacts, 2 more than the Type 1 plug. The top row contains 2 small signalling contacts, the middle row consists of a central earth contact and two outer contacts used for power supply, and the third row has two more contacts which, if connected, can be used for three-phase charging (these are absent in the above photo, which is a single-phase charging point).
The Type 1 charging plug
The Type 1 plug is a Japanese and American standard for EV charging. The plug has a rounded housing and a latch which stops the plug moving in the socket.
The connector contains 5 contacts. Much like the Type 2 plug, the Type 1 contains 2 small signalling contacts, an earthing contact and two contacts for power supply.
The main limitation of the Type 1 connector is that it is only suitable for 'single-phase' charging, hence leading to the development of the Type 2 connector for European vehicles.
Power transfer and speed
AC charging can transfer up to 22kW of power, but this depends on the charging point and the onboard charger (inside the vehicle) that converts AC to DC. The capability of the onboard charger is key to the speed of charge; for example, if the vehicle was manufactured with a 3.7kW onboard charger, then the vehicle will be limited to charging at 3.7kW or less, even if plugged into a higher rated charge point, i.e. if plugged into a three-phase 22kW charging point, it will still only charge at 3.7kW. If the charge rate is limited by the onboard charger, then DC charging is required to recharge the battery at a faster speed.
Rapid Charging (DC)
For faster charging, DC must be used. Just as with AC charging, the vehicle battery must be fed DC electricity, so a conversion from AC to DC must occur. The key difference is the location of this conversion; for rapid DC charging, AC is converted to DC within the charging station and the current is then fed through the cable and straight into the vehicle battery. There are two types of DC charging; CHAdeMO and the Combined Charging System (CCS).
CHAdeMO
CHAdeMO is a rapid DC charging standard designed by Japanese vehicle manufacturers in 2010. The name is said to stand for CHArge de MOde, but is also derived from the Japanese phrase "O cha demo ikaga desuka", meaning "How about a cup of tea?" hinting at the time it would take to charge a vehicle.
CHAdeMO is capable of charging vehicles at to 62.5kW.
Currently, CHAdeMO is the only standardised charging protocol that has been verified for Vehicle-to-Grid (V2G) charging.
CCS
Combined Charging System, or CCS, is now the standard for DC charging on new vehicles in Europe. The CCS connection combines the inlets for AC and DC using shared communication pins, so the vehicle coupler is formed of a Type 2 plug with 2 DC pins below.
When AC charging, only the top part of the inlet is used. The 2 DC pins are normally covered. When using the CCS system, the larger coupler uses the whole inlet. This cable and connector is always a part of the charging station.
CCS is capable of charging vehicles at up to 350 kW.
Rapid AC
Rapid AC charging was used in early Renault ZOE models, but it is no longer commonly used on passenger cars. Rapid AC chargers provide power at up to 43kW and use the Type 2 charging plug as a standard. There are applications for heavy vehicle charging, such as trucks and buses, and we can provide these charging points.
Charging Modes
Charging methods are also commonly referred to by 'mode'. There are four categories, simply referred to as Mode 1, Mode 2, Mode 3, and Mode 4. Although this seems like another layer of jargon, the four categories are an easy way of categorising charging types.
Mode 1
This is the simplest method of charging. The vehicle is connected to the power grid using a standard 3-pin socket in a home or building with a simple cable. Mode 1 charging is generally only used to charge vehicles with minimal power requirements, such as scooters/mopeds. Mass vehicle manufacturers no longer allow this method of charging to be used on large vehicles because the cable is live at all times, even when the vehicle is unplugged. Alongside this, there is no communication between the plug and vehicle to monitor a charge.
Mode 2
Mode 2 charging is similar to Mode 1, but a cable with an in-cable control box is used. Charging is again done through the use of a 3-pin plug or industrial 'commando' (CEE) plug, but the control box limits the charge rate to avoid overloading the mains socket and wiring and often has a built-in protection device which monitors power draw and temperature. The protection device greatly improves safety over Mode 1 charging, although it is not intended as a permanent solution.
Mode 3
Mode 3 charging can be seen as a 'step up' from Mode 1 and 2. Instead of using a cable with 3-pin plug, Mode 3 charging uses a fixed charging point containing the protective device with a dedicated socket or permanently attached cable. This method is much safer than Mode 1 or Mode 2 charging as the charging point is wired on a separate electrical circuit. Mode 3 charging is AC, so the charger within the vehicle converts AC power to DC.
Mode 4
Mode 4 charging is much the same as Mode 3, but charging uses DC power not AC. Like Mode 3, a fixed charging point with its own dedicated circuit and control electronics is used. The AC to DC conversion happens in the charging station itself, not within the vehicle, then the DC power is sent directly to the battery. A large separate cabinet often houses the AC to DC converter. Due to the high voltage and current, the charging cable is always tethered to the charge point (like at a fuel station) - you cannot use your own cable to charge.
Thanks to our wealth of automotive, electrical and sustainable consultancy experience, we can advise you on all things EV.