Can national networks handle electric cars?

Glossary: ​​Electromobility from A - Z

Many terms relating to electromobility are technical vocabulary and require explanation. Here you can find out what AC charging, recuperation, type 2 plugs or the abbreviation BEV mean.

battery pack

An accumulator (short form: accumulator) is a storage element for electrical energy on a chemical basis, which is rechargeable (secondary cell). Through the Stringing together several battery cells creates a battery. Colloquially, the terms "accumulator" and "battery" are also used synonymously for an "energy store".

battery

The battery as Energy storage is the heart and at the same time the most expensive component of an electric vehicle. But the size alone does not guarantee a long range. The vehicle must also use the stored energy sparingly. Batteries age - even if they are not used. Their maximum storage capacity is reduced over time (calendar aging) and depending on the number of charges (see also: cyclical aging). In order to avoid confusion with the starter battery (see below), one also speaks of the traction or high-voltage battery.

Battery: starter battery

Like every car with a combustion engine, electric vehicles have one 12 volt starter battery. This is necessary to activate the high-voltage system of the vehicle before driving off and to supply loads such as control units, lighting or infotainment with energy. If the starter battery is empty or defective, the vehicle cannot be started - as with a combustion engine.

Battery charge level (SoC)

The state of charge of the battery (engl. State of Charge = SoC) indicates how much energy can still be used in the battery. The SoC is usually given in percent. However, some manufacturers are also based on the classic fuel gauge and display the SoC graphically (without a specific percentage). A battery should ideally be kept in a condition between 20 and 80 percent, this benefits the service life.

Battery guarantee

In order to create trust in the new technology, the vehicle manufacturers give generous guarantees on the traction battery. This can be a Guarantee for total failure or for one Loss of capacity the battery. Depending on the manufacturer, traction batteries have a guaranteed storable amount of energy of mostly 70 percent within eight years or up to 160,000 kilometers in operation. If a battery has less power within this time, but the entire battery does not necessarily have to be replaced, a modular repair is often sufficient. Since all cells are connected in series, the weakest cell is the one that limits the capacity of the remaining cells.

Battery management system (BMS)

The battery management system is the "brain" the high-voltage battery. It monitors the status of the cells during operation and charging. When charging, the BMS specifies the possible charging power based on various environmental data, especially with fast charging.

Battery rental

Initially, several manufacturers offered to rent the battery of the electric car, but now this option is only available from Renault. Renting a drive battery reduces the purchase price by several thousand euros. The Battery rental costs are dependent on the mileage with some providers, others charge a fixed price per month. When selling a vehicle with a rental battery, it is important to make sure that the buyer accepts the rental agreement.

BEV

Abbreviation from English: B.attery E.lectric Vehicle

Bidirectional charging

With bidirectional charging, the electric vehicle can not only take energy from the grid, but also release it back into the grid, also known as vehicle-to-grid (v2g). As part of an intelligent network ("Smart grid") the battery could then store excess capacity from solar systems, for example, and transfer it back to the house or the power grid when required. It is also conceivable to use such vehicles as a power source for broken down e-cars. So far, bidirectional charging has been demonstrated in research projects, commercial solutions for domestic use are not yet available.

Board charger

The on-board charger is required in the electric vehicle to convert alternating current from the power grid into direct current for the battery. An 11 kW on-board charger can charge on three phases with 16 amperes each. A 3.7 kW on-board charger only uses one current phase with 16 amps. The single-phase charging takes significantly longer than that three-phase charging.

Fuel cell car (FCEV)

A fuel cell on board the vehicle generates electricity from hydrogen. In the fuel cell, hydrogen from the tank and atmospheric oxygen from the ambient air generate electrical energy, while heat and water are produced as waste products. Fuel cell vehicles (engl. Fuel Cell Electric Vehicle - FCEV) are driven by an electric motor - therefore they are also considered to be electric cars. They also need an - albeit smaller - high-voltage battery as an intermediate storage device.

Chademo system

Chademo is a fast charging system according to Japanese standards (CHArge de MOve = freely translated from Japanese: "Would you like a cup of tea?"). The charging capacities are predominantly 50 kW, even if higher charging capacities would in principle be possible. In Germany, Chademo is only offered by Nissan and Mitsubishi. Newly presented electric vehicles in Europe rely on the European CCS standard. More and more fast charging stations no longer offer Chademo charging cables.

CCS store

CCS is short for Combined charging system and describes a (combined) fast charging system according to European standards. The charging power of the charging stations is now up to 350 kW. At CCS, the type 2 AC plug has been expanded to include two additional contacts for direct current charging. This allows the vehicle with a CCS socket to be charged using direct or alternating current. The quick charging function is included in the standard scope of many electric cars. If this is not the case, the ADAC strongly recommends ordering the quick charge option. With fast charging, the flexibility of an e-car is significantly increased, and selling a used e-car without a fast-charging function is likely to become more and more difficult.

Electric car: definition by law

As Electric car within the meaning of the Electromobility Act a) the pure battery electric vehicle (BEV), b) the externally chargeable hybrid vehicle (plug-in hybrid vehicle - PHEV) and c) the fuel cell electric vehicle (FCEV) - as defined by the Federal Ministry for Transport and infrastructure the electric car.

E-mark

The license plate for electric cars can be applied for since 2015 and should make an electric car recognizable as such. In order to receive an E-license plate, the vehicle must have a minimum electrical range of 40 kilometers (from 2022: 60 km) or emit a maximum of 50 grams of CO₂ per kilometer. The E. always stands at the end of the Combination of letters and numbers.

Energy density

The energy density gives the amount of energy stored per volume (Megajoules per liter) or mass (Megajoules per kilogram). The value describes how much energy, for example, one kilogram contains or can be stored. Compared to liquid fuels such as diesel or gasoline, accumulators have a significantly lower energy density.

Solid battery

If you ask for one future battery technology, is usually called the solid-state battery. This is considered to be extremely temperature-resistant and safe, as it lacks the liquid electrolyte. Advantage: no cooling is required. Furthermore, the solid-state battery should have an energy density that is about twice as high as that of today's lithium batteries. The result: significantly longer ranges.

frequency converter

There is DC voltage in the batteries. The drive of an electric vehicle, however, often works with an alternating current machine. To "convert" the energy between the two types of current, a frequency converter (often as Inverter which converts voltage and frequencies according to the required operating mode.

Direct current (DC)

DC stands for Direct Current, translates to direct current. Here electric current flows in a constant direction, in contrast to alternating current, the direction of which changes periodically. Stored energy in batteries is available in the form of direct current.

High Power Charger (HPC)

High Power Charger (HPC) or ultra-fast charging stations Charging capacities from 150 to 350 kW. HPC charging stations work at voltage levels of up to 1000 volts and offer up to 500 amperes of charging current. The electric vehicle ultimately determines how much of this charging power can be used. With fast charging, not only the maximum charging power is relevant, but also the average charging power in the range of ten to 80 percent battery charge level. The HPC network has grown rapidly along the motorways and increasingly also in the cities since 2019. There are now numerous vehicles on the market that can draw between 100 and 270 kW of charging power.

Hybrid vehicle

Hybrid vehicles have at least two different drive technologies and separate energy storage devices (e.g. combustion engine and electric motor). They act individually or in combination for the drive. This combination makes it possible to work with the optimal efficiency of the drive, thereby improving efficiency, range and pollutant emissions. Hybrid vehicles also have an electrical storage device. The bigger, the further you can drive purely electrically.

Inductive charging

Inductive charging means contactless charging. It will energy by means of high-frequency alternating currents transmitted wirelessly. This means that e-cars can be charged using charging elements in the lane, in parking lots or garages. The technology is already used in cell phones and electric toothbrushes, but it is not yet standardized and ready for series production in motor vehicles.

Kilowatts (kW)

The powerof engines or the charging power of charging stations is given in kilowatts.

Kilowatt hour (kWh)

The electrical work is given the unit kilowatt hour (kWh). In electromobility, the Energy content of the drive battery specified in kilowatt hours. As a result, the power consumption in the car is measured in kWh per 100 kilometers. Note: In electromobility, the kilowatt hour is the relevant unit of measurement, comparable to the liter for fuel in internal combustion engines.

Charging infrastructure

The charging infrastructure is between public and private infrastructure differentiated. Private charging infrastructure is only accessible to a closed group of users, for example at home or in a company. Public charging infrastructure is generally available to the public and must meet the requirements of the charging station ordinance. The Federal Government is planning and promoting the nationwide development of public charging infrastructure and has set up the National Charging Infrastructure Control Center for this purpose.

Charging curve

The Course of the charging power referred to above the state of charge. The charging curve is particularly interesting for fast charging on long journeys, because the BMS reduces the charging power as the charge level increases. The higher and more constant the DC charging curve, the more long-distance an electric car is.

Charging power

The charging power is understood as the electrical power in kilowatts (kW) with which a traction battery is charged. Multiplied by the charging time, this results in the capacity stored in the battery in kilowatt hours (kWh). When charging with alternating current (AC), the charging power is usually constant and is only reduced shortly before the end of the charging process. When charging with direct current, the charging power changes depending on the respective charge and temperature status of the battery and other factors.

Charging point / charging column

A charging station usually has several charging points. In statistics on the expansion of the Charging infrastructure is counted differently: sometimes the number of charging points is given, sometimes the number of charging columns or charging stations. This can easily lead to confusion.

Charging plug

There are two ways to charge a car - via Alternating current (AC) and above Direct current (DC). In Europe, the type 2 plug for AC charging and the CCS plug for DC charging are standard. Public AC charging stations are always equipped with a type 2 charging socket. Appropriate adapter cables are available for older vehicles with a type 1 connection on the vehicle. Some vehicles still have the Japanese standard Chademo for quick charging. An adapter to charge vehicles with a Chademo connection to CCS stations is not available. Further information can be found here: Charging an electric car.

Charging tariffs

Most of the charging stations in the public area allow activation using Charge card or Smartphone app. In addition, payment must also be possible without a charging contract - called ad hoc charging. Charging tariffs are offered with or without a basic fee and with very different electricity prices and billing types. In addition, tariff components such as entry fee, parking fee or blocking fees are possible. That is why the ADAC offers with ADAC e-Charge a fair charging tariff at uniform prices in Germany as well as in neighboring countries.

Charge losses

When charging an electric car, this inevitably occurs Power losses. The range of these charging losses is between ten and 20 percent and depends on various factors. Charging losses are reflected in the calculation with higher costs.

Load management

If several electric cars are charging at the same time, the connection must not overload. Load management systems take care of that. There are two types: At static load management a fixed charging capacity is made available to the wallboxes. At the dynamic load management the current power consumption of the building is measured and calculated on the basis of what remains as power for charging the electric cars depending on the situation. The current "remaining power" is now distributed flexibly, and the electricity potential in the building is used in the best possible way. You can find more information here: Wallboxes with load management.

Lithium Ion Battery

Lithium-ion batteries are characterized by a high cycle stability (charge / discharge) and one - in relation to others chemical energy storage - high energy density and low self-discharge.

Memory effect

The memory effect describes the Loss of capacity of a battery, the with frequent partial discharge entry. This problem was particularly evident with old nickel-cadmium batteries. Electrically, the memory effect shows up in an early voltage drop, although the entire available capacity has not yet been used. Lithium-ion batteries are not affected.

Mild hybrid vehicles

Normal hybrids or electric cars have high-voltage components that usually work with around 400 volts and are specially protected. Mild hybrid systems are working more and more frequently 48 volts and support the combustion engine, maintain speed and recover energy when braking. This reduces fuel consumption.

Emergency charging cable

As an emergency charging cable, the Charging cable for the household socket referred to, which is usually included with an electric vehicle. The professional name is In-Cable Control and Protection Device (IC-CPD) - formerly also In-Cable-Control-Box (ICCB). The IC-CPD monitors the charging process at a household socket. Some IC-CPD have options to reduce the charging current.

Green electricity

Green electricity is a term for electrical energy, the from renewable sources is obtained, for example from hydropower, sun and wind energy. Readers note: The eco-balance of the drive types.

One-pedal driving

There are e-cars that have a "one-pedal-feeling" concept, such as the BMW i3 or the second-generation Nissan Leaf. As soon as the driver just takes his foot off the "accelerator pedal", one sets clearly noticeable delay (the recuperation). Once you have got used to the delay, you can drive these e-cars with just one pedal. With anticipatory driving, the mechanical brake is only required for more powerful braking or for emergency braking.

Plug-in hybrid

As with all-electric vehicles, the battery of a plug-in hybrid can have a plugcharged to plug in. If the battery is empty after about 30 to 80 kilometers of electrically powered travel, the vehicle functions like a hybrid and can continue to recover braking energy and use it again (see term: recuperation).

Range extender

A range extender (also called REX) is a small petrol engine that uses a generator to generate electricity for the electric motor when the traction battery runs empty. In an emergency, the driver is therefore independent of a charging station for a certain range and continues to drive despite the empty battery.

Range

The range indicates How many kilometres the electric car with a charge can drive. Basically, the range depends heavily on the individual driving style. The manufacturer's prospectus values ​​are created under ideal climatic conditions with a moderate driving style. In the electric cars, the on-board computer calculates a forecast value for the remaining range based on the previous driving style, possibly depending on the outside temperature, the route and even the topography of the route to be driven.

Recuperation

Recuperation (from the Latin recuperare = to regain) means Energy recovery. When the car brakes, the (kinetic) energy is converted into heat and is lost. This kinetic energy can be recovered in electric and hybrid vehicles. Here's how: When braking or driving downhill, the electric motor becomes an electricity generator and feeds this energy back into the traction battery. In city traffic in particular, recuperation can significantly reduce fuel consumption. Nice side effect: less brake wear.

Unbalanced load

The power connection of buildings in Germany has three conductors, also called phases. If electric cars with a single-phase on-board charger are connected, an unbalanced phase load may arise in the network. This can lead to problems in the neighboring business, for example. In order to avoid this risk for the general public, a vehicle may be charged single-phase with a maximum of 20 amperes, even if the on-board charger could handle more charging current.

Fast charging

By definition, charging is included as fast charging Charging capacities over 22 kW designated. Fast charging is almost always done using direct current. The only exception is the first-generation Renault Zoe model, which could charge up to 43 kW of alternating current.

Smart grid

As a smart grid intelligent power grids designated. Electric vehicles can become part of the smart grid by being charged time and load-controlled or even feeding energy back into the grid (see term: bidirectional charging). The smart grid is still in the development phase.

Synchronous machine (PSM versus ASM)

In the case of the motors of electric cars, permanent magnet synchronous machines (PSM) and separately excited asynchronous machines (ASM) differentiated. Both have specific advantages and disadvantages. The advantages of the PSM are a higher power density and a higher degree of efficiency, while the disadvantages are the higher costs and the use of rare earths. An ASM is more robust, cheaper and has a freewheel when switched off.

Environmental bonus

The environmental bonus is one state purchase premium, with which e-mobility is to be promoted in Germany. The environmental bonus can only be applied for on the website of the Federal Office of Economics and Export Control (BAFA *). The vehicle must be on the list of eligible electric vehicles. You can read more about this here.

Full hybrid

In contrast to the mild hybrid, the Electric motor in the case of a full hybrid, so does the vehicle drive alone, especially when starting up and at low speeds.

Wallbox

Wallboxes enable a higher charging capacity than conventional household sockets: single-phase with up to 4.6 kW and three-phase with up to 22 kW. A wallbox installed by a specialist electrical company contains an FI circuit breaker and minimizes the dangers of electrical current. Wallboxes differ in terms of equipment features such as energy meters, access control or connectivity. Charging devices with a charging capacity of up to eleven kW must be registered with the network operator, and above eleven kW they are subject to approval. This is usually done by a specialist electrical company. Here you can find out which wallboxes do well in the ADAC test.

Alternating current (AC)

Alternating current is electrical current, the direction of which changes periodically. AC stands for Alternative Current (ie "alternating current").

Cycle stability

A battery is charged and discharged, this happens in cycles. In order for a battery to have a long service life, it must have high cycle stability and a correspondingly high number of Charge and discharge cycles withstand without the battery properties noticeably deteriorating.

Terms and explanations were compiled by the ADAC Technik Zentrum, specialist department for electromobility.


* The link leads to an external page for whose content the ADAC is not responsible

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