Glossary of Terms

A

AC

“Alternating Current” is an electric current that reverses direction at regular intervals.  Electric car motors are either AC or DC with most of the new ones being of AC type.

Amp

A unit of electric current.

 

B

Back Office

The Back Office represents the data management centre used to monitor and remotely access the EV infrastructure. It typically holds a database of the installed charge point equipment and authorised infrastructure users. The Back Office is usually termed the Charge Point Management System or CPMS.

Battery

The battery represents an electricity storage medium that feeds current to the motor. Most EVs use a Lithium Polymer batteries.

C

Charge Point

The dedicated infrastructure (upstand or wall unit) where an Electric Vehicle can be plugged in and charged. A charge point unit encompasses one or more dedicated sockets or tethered plugs that can charge EVs. A charging station encompasses the charge point unit and all the ancillary equipment and signage etc that goes with it including a weather shelter.

D

DC

“Direct Current” represents an electric current of constant direction. Electric car motors are either DC or AC, with DC motors generally being less expensive to buy and simpler to use on an EV.

E

EV

An Electric Vehicle, or EV, describes any vehicle that uses electric motors as part of its drivetrain. Specific examples include; pure battery EV, hybrid, plug-in hybrid, extended range EV and hydrogen fuel cell EV.

E-REV

An Extended Range Electric Vehicle or EREV or RE-EV is a vehicle that uses an electric motor to power the movement of the car. However, there is another internal combustion engine which acts as a generator for the battery thus extending the range of the car. Unlike a PHEV, E-REVs do not use the petrol/diesel engine to directly power the wheels.

F

Fast Charge

Charging at a 7kW is generally Fast charging. Usually it takes 4 hours to fully charge an EV with a 24kWh traction battery at this power level. Rapid charging is even quicker.

H

HCU

“Home Charging Unit” is a dedicated charge point unit for use at home. They incorporate a number of safety features to prevent fires or short circuits and often employ intelligent features such as timers and communication with a CPMS.

Hybrid

A car that integrates a traction battery and an electric motor to enhance the efficiency of the engine. The battery’s charge is provided by the ICE engine, but it cannot be plugged into an electrical supply.  Hybrids travel a very short distance on electric power only.

I

ICE

“Internal Combustion Engine” is an engine powered through the burning of fossil fuels (e.g. petrol or diesel).

 

Incentives

Many governments offer incentives to encourage buyers to choose an EV. Grants that lower the purchase price are available in many countries. In the UK EV purchasers can take advantage of a 35% Government subsidy on a new electric car’s list price (the Plug-in Car Grant; a subsidy of up to £5,000 off an eligible electric car). For the commercial vehicle world, the UK Government offers a 20% subsidy off the price of an electric van (the Plug-in Van Grant; a subsidy of up to £8,000 off an eligible electric van) Other incentives for EVs can include free parking, zero road tax, low company car tax (Benefit in Kind tax) and exemption from city emissions and congestion charges (subject to application).

Interoperability

The ability to communicate and use information from diverse systems and hardware and create a network that serves the purpose of the connected parties. Interoperability allows EV drivers to use different charging equipment in different regions of the UK with the same membership card or smart phone application.

K

kWh

“Kilowatt-hour” – a unit of energy equivalent to the energy transferred or expended in one hour by one kilowatt of power.

 

L

Lead Acid Battery

A lower energy density and service life battery than a Lithium polymer battery. This battery type is relatively inexpensive, has a well-developed recycling stream and works better at lower temperatures than other battery chemistries.

Lithium Ion Battery Li-ion

Is the name for a group of Lithium chemistries used for EV batteries. They rely upon the movement of electropositive Lithium ions in the electrolyte and across the electron impermeable separator that sits in between the two electrodes (anode and cathode). The electrons are forced to flow through the EV circuitry to recombine with the Lithium ions at the cathode.

Lithium ion cells offer a good energy density and a reasonable power density. They also last for a long time and do not exhibit the memory effect that other chemistries suffer from (e.g. Nickel Metal Hydride or Nickel Cadmium). After about eight to ten years of life an EV Lithium ion battery is expected to have at least 80% of its new capacity left. Please note that inexpensive Lithium ion cells used in electric bicycles are not manufactured in the same way as EV cells and so do not last for as many charge/discharge cycles (typically 1000 versus 10000 cycles). Please also note that Lithium ion cells are particularly sensitive to high temperatures which can shorten battery life.

N

NiMH Battery

“Nickel-Metal Hydride” is a type of battery used in some older hybrid vehicles, offering better energy density than lead acid but less than lithium ion.

P

PHEV

“Plug-in Hybrid Electric Vehicle” – is a hybrid EV with a larger traction battery pack which can also be charged up by plugging in to a grid electricity supply.

Plugged-in Places

A UK government scheme that provides funding for specific regions to install charging infrastructure. Funds may still be available so please search online for OLEV plugged-in places.

Pure Electric

A battery electric vehicle powered solely by electric machines (electric motors) using power provided by on-board batteries.

Q

Quadricycle

A four-wheeled vehicle with low power and of the same class as a moped or scooter (e.g Renault Twizy). Quadricycles generally only require a motorbike license to legally drive them on UK roads. However, to drive the Renault Twizy you must possess a UK car driving license.

R

Rapid Charge

Rapid charging (20-50kW DC or 22-43kW AC power output) is only available from dedicated charging equipment resembling a petrol pump. The units typically possess one or more tethered standardised plug that can be attached to a compatible EV. A 50kW output DC rapid charger can typically provide an 80% charge to a compatible EV in around 20-30 minutes. Regular rapid charging can affect the battery life, but it provides a convenient option to extend the range of an EV on longer journeys.

Range

The distance you can travel before running out of fuel and/or power.

Range Anxiety

A term used to describe the fear of running out of battery whilst driving an EV. Real-world tests show that range anxiety recedes over time as drivers become more comfortable with their cars’ actual range capability and get used to finding charge point unit locations.

Regenerative Braking

An energy recovery system used in most EVs that can help charge the battery whilst the car is slowing down. Typically the electric motor acts as the generator, so power can flow both ways between it and the battery.

RFID Membership Card

RFID membership card is a card issued by EV infrastructure operators and used by EV drivers to obtain access to charge point units in order to charge their EV. Users need to check the card compatibility for different regions and charge point unit providers. Future plans will enable cards to be compatible with most charge points in the UK and across the EU.

S

Standard Charge (3kw)

Typically refers to charging from a domestic socket that will take approximately eight to twelve hours to charge an average mainstream electric car from flat to 100% SOC.

V

V2G

“Vehicle-to-Grid” refers to the transfer of electrical current from the battery of an EV back into the National Grid whilst plugged into the mains. This technology will help balance the grid in periods of high demand whilst also benefiting the consumer for peak and off-peak charging rates.

W

Well to Wheel or W2W

“Well-to-Wheel” is a term used to identify the measurement of 0CO2 emissions of a car, taking into account the production of the fuel or electricity and its use by the vehicle during motion.