Electric Vehicle Jargon Explained

You may have heard terms such as kW, WLTP or DC rapid charging and wondered what they mean. While EV terminology can seem complicated at first, most of the jargon is straightforward once you understand the basics.

This guide explains some of the most common electric vehicle terms in plain English, helping you compare models, understand charging and feel more confident about EV ownership.

EV, BEV, HEV, PHEV, MHEV and REX

EV: stands for electric vehicle and is often used as a catch-all term for vehicles that use electric power. However, there are several different types of electrified vehicles.

Battery Electric Vehicle (BEV): refers to a vehicle powered entirely by a battery and electric motor. There is no petrol or diesel engine.

Hybrid Electric Vehicle (HEV): describes a vehicle that combines an internal combustion engine with an electric motor. The battery is charged through regenerative braking and the engine itself.

Plug-in Hybrid Electric Vehicle (PHEV): is a hybrid that can also be plugged in to recharge its battery, allowing it to travel short distances using electric power alone.

Mild Hybrid Electric Vehicle (MHEV): uses a small electric system to support the engine and improve efficiency. Unlike a PHEV, it cannot be plugged in to charge.

REX: stands for range extender. In a range-extended electric vehicle, a small petrol engine generates electricity for the battery when required, rather than directly driving the wheels.

What do kW and kWh mean?

Two of the most commonly used EV terms are kW and kWh. Although they look similar, they measure different things.

kW

A kilowatt (kW) is a unit of power. In electric vehicles, it is used to describe either the output of an electric motor or the speed at which a charger can deliver power.

A higher kW figure can mean stronger performance from a motor or faster charging when referring to a charge point.

kWh

A kilowatt hour (kWh) is a unit of energy. It measures how much electricity a battery can store.

How do they work together?

Put simply, kW tells you how quickly energy is being delivered, while kWh tells you how much energy is available. When comparing electric vehicles, battery capacity is usually measured in kWh. In most cases, a larger battery can support a longer driving range.

Battery capacity and state of charge

Battery capacity refers to the total amount of energy an EV battery can store. It is measured in kWh.

A vehicle with a larger battery will generally be capable of travelling further between charges, although factors such as driving style, weather conditions, weight and aerodynamics will also affect range.

Manufacturers often quote both total battery capacity and usable battery capacity. The usable figure may be lower because part of the battery is reserved to help protect long-term battery health.

State of Charge (SoC) shows how much energy remains in the battery. It is displayed as a percentage, much like a fuel gauge in a petrol or diesel car.

Many EV owners try to keep the battery between 20% and 80% during day-to-day use, which can help reduce battery degradation over time.

AC and DC charging explained

Electric vehicles can be charged using alternating current (AC) or direct current (DC).

AC charging is typically used at home, at workplaces and at many public destination chargers. Because EV batteries store direct current, the vehicle must convert AC electricity before it can be used. This process takes place within the car.

DC charging bypasses this conversion process and supplies electricity directly to the battery. This allows much faster charging and is commonly found at rapid and ultra-rapid public charging stations.

Many drivers install a 7kW home charger to make charging more convenient and significantly faster than using a standard three-pin plug.

WLTP range and energy efficiency

Range is one of the most important figures for many electric vehicle buyers.

Manufacturers use the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) to provide a standardised estimate of how far a vehicle can travel on a full charge.

WLTP testing includes a variety of driving conditions, creating a consistent benchmark that allows drivers to compare vehicles more easily.

You may also see energy efficiency figures expressed as miles per kilowatt hour (mi/kWh). This indicates how effectively a vehicle uses the energy stored in its battery.

Generally, the higher the efficiency figure, the further the vehicle can travel using the same amount of electricity.

Understanding real-world range

Official WLTP figures provide a useful comparison point, but real-world range can vary.

Real-world range refers to the distance an electric vehicle is likely to achieve in everyday driving conditions. Factors that can affect range include:

• Cold weather
• Motorway driving at higher speeds
• Use of heating or air conditioning
• Vehicle load and passenger weight
• Driving style

As a result, actual driving range may be lower than the official WLTP figure, particularly during winter months or on long motorway journeys.

Charging connector types

Several charging connector standards exist around the world.

Combined Charging System (CCS): is currently the most widely used rapid charging standard in the UK and across Europe. Most modern EVs use CCS for public rapid charging.

CHAdeMO: was widely used by early electric vehicles, particularly Japanese models such as older versions of the Nissan Leaf. However, it is becoming less common as CCS adoption continues to grow.

North American Charging Standard (NACS): was developed by Tesla and is primarily used in North America. In the UK and Europe, Tesla models typically use the CCS2 connector standard.

Vehicle-to-Grid and Vehicle-to-Everything

Vehicle-to-Grid (V2G) technology allows compatible electric vehicles to send electricity back to the power grid when connected to suitable infrastructure.

The aim is to help balance electricity demand and potentially allow drivers to make use of stored battery energy when required.

Vehicle-to-Everything (V2X) is a broader term that describes an EV's ability to supply power to external devices.

Depending on the vehicle, this could include powering tools, camping equipment, household appliances or even charging another electric vehicle.

Over-the-Air updates

Many modern electric vehicles rely heavily on software to manage performance, battery systems and connected features.

Over-the-Air (OTA) updates allow manufacturers to update vehicle software remotely through a mobile data connection or Wi-Fi.

These updates can introduce new features, improve efficiency, enhance existing systems or resolve software issues without requiring a visit to a dealership.

As a result, some electric vehicles can continue to gain new functionality long after they have left the factory.

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