Understanding Electric Vehicle (EV) Charging

Understanding Electric Vehicle (EV) charging

Understanding Charging Infrastructure

The rate at which the plug-in vehicle market develops in the UK will be determined by a range of factors, such as consumer acceptance and oil prices, which are difficult to predict. Independent forecasts suggest that hundreds of thousands of plug-in vehicles could be on the road by 2020 and we need to be equipped to deal with this; but we also need to be ready to accommodate an even more rapid rate of growth should this occur.
With the UK’s spend on electric vehicles set for £7bn by 2014, the charging infrastructure will play a pivotal role in the future success of electric vehicles to ensure users have optimum access to power anytime, anywhere. Charging systems are suitable for domestic and commercial environments, as well as roadside, car parks and petrol stations.

Vehicle Types

Electric vehicle (EV) is the umbrella term for any vehicle that is powered, in part or in full, by a battery that can be directly plugged into mains electricity. In short, any vehicle that can be plugged in including pure-electric, plug-in hybrid and extended-range electric vehicles, these aren’t to be confused with Hybrid’s.

  • Pure-Electric Vehicle (Pure-EV) – A vehicle powered solely by a battery charged from mains electricity. Currently, typical pure-electric cars have a range of approximately 100 miles but are improving all the time.
  • Plug-In Hybrid Electric Vehicle (PHEV) - A vehicle with a plug-in battery and an internal combustion engine (ICE). Typical PHEVs will have a pure-electric range of over 10 miles. After the pure-electric range is utilised, the vehicle reverts to the benefits of full hybrid capability (utilising both battery power and ICE) without range compromise.
  • Extended-Range Electric Vehicle (E-REV) – A vehicle powered by a battery with an ICE powered generator on board. E-REV’s are like pure-EV’s but with a shorter battery range of around 40 miles. Range is extended by an on board generator providing many additional miles of mobility. With an E-REV the vehicle is still always electrically driven.
  • Hybrid – A hybrid vehicle is powered by, either or both, a battery and an ICE. The power source is selected automatically by the vehicle, depending on speed, engine load and battery charge level. This battery cannot be plugged in; charge is maintained by regenerative braking supplemented by ICE generated power. A number of fuels can power hybrid ICE’s, including petrol, diesel, Compressed Natural Gas, Liquid Petroleum Gas and other alternative fuels.

EV’s can meet our needs…

  • 50% of worldwide population living in cities
  • In Europe, over 80% of Europeans drive less than 63 miles in a typical day
  • In the UK, the average individual journey length is 8.6 miles
  •  In the UK, the average total daily distance travelled is <25 miles
  • 23 hours is the average time a car is parked each day
  • UK target to cut CO2 emissions by at least 80% by 2050
The average total daily distance travelled is well within the range of Electric Vehicles (EVs). However, consumers’ purchasing decisions are influenced by the potential to travel further, not just their average journey patterns. Therefore it will be important for consumers to be reassured of the ability to make longer journeys and own plug-in vehicles, particularly when looking ahead to breaking into the mass-market of consumers in the 2020s and 2030s. 

Models of Charging

There are a number of options available in the UK for the charging of electric vehicles. A range of factors will influence a consumer’s decision to adopt any of the following modes and types of infrastructure, including the vehicle type, desired speed of charge, long-term interoperability and UK wiring regulations. The following set of recommendations is based on the current development of products and standards, and aims to promote safe and energy efficient charging practices.

There are 4 key modes (as defined in the standard BS EN 61851-1) for the charging of an electric vehicle, as summarised below:

  • Mode 1 charging: Non-dedicated circuit and socket-outlet, charging without cable-incorporated RCD protection
    Mode 1 should not be used for the charging of an electric vehicle because RCD protection, which is necessary for a safe charging system, cannot be guaranteed at all outlets .
  • Mode 2 charging: Non-dedicated circuit and socket-outlet, charging with cable-incorporated RCD protection
    Mode 2 can be used for the charging of an electric vehicle in locations where there is no dedicated charging installation (Mode 3 or 4, see below), and for use by legacy vehicles. Mode 2 cables are provided with an in-cable control box (including RCD), set and adjusted to a specific charging power, and guarantee the provision of RCD protection during charging.
  • Mode 3 charging: Fixed and dedicated socket-outlet
    Mode 3 can be used for the charging of an electric vehicle and this is the preferred solution in the long term. Mode 3 chargers are defined in 2 configurations, either with a tethered cable or a dedicated socket-outlet.
  • Mode 4 charging: Dedicated rapid charging, DC supply
    Mode 4 is a necessary service function for rapid charging, for use as roadside assistance and service station charging on long journeys.

 Types of Charging and Standard Charging Times

(speak to vehicle manufacturer for specific expected times)

  • Slow – using a standard 13 amp supply (10 – 12 hours for full charge)
  • Slow – using a 16 amp supply (6 – 8 hours for full charge)
  • Fast – uses single or three phase 32 amp supply (3 – 4 hours for full charge)
  • Rapid – uses a Direct Current supply (typically 80% charge in 30 mins)

Installation Notes

The installation of EV charging stations needs to be undertaken by competent and qualified electrical engineers and ideally these engineers should have, at the very least, attended one of a number of courses currently available such as the NICEIC’s EV Introductory Course (speak to Rexel Energy Solutions for course details) or the full two day installation course offered by organizations such as Group Horizon which results in a certificate being awarded.

It is recommended that anybody looking to undertake the installation of EV charging points should obtain a copy of the latest set of regulations issued by the IET.

There are various types of charging units available which reflect the mode of charging, whether it is a residential, commercial or public charge point or if the charging point is to be wall mounted or ground mounted. Speak to a qualified electrical engineer as above to assist in designing which unit is best suited to your situation and requirements.

Are you ready for the Electric Vehicle revolution?

Rolec's EV charging points are the ideal solution for charging electric vehicles. Rolec EV has manufactured and supplied over 18,000 charging units throughout the UK and mainland Europe, and can offer electric vehicle charging solutions for every vehicle and location.