PS, Nm, Vmax - some terms are the same for electric cars as for conventional cars. But it is also important to learn a few new words.
The electric car has finally established itself in Germany. Even during the Corona crisis, battery-powered vehicles and plug-in hybrids were more in demand than ever. And with them, some new terms seep into the driver's vocabulary. A small overview.
Accumulator: a rechargeable store for electrical energy on an electrochemical basis. In the narrower sense, the term accumulator or rechargeable battery means only a single storage cell, but in general the interconnected storage elements as they occur in electric cars are also referred to as “accumulators”. In many cases, the term “battery” is used synonymously today, the more precise “rechargeable battery” is only recommended when specifically emphasizing rechargeability.
Amp: is the unit of electrical current (A). If one imagines the current flow as the flow of water through a pipe, the current strength corresponds to the pipe diameter. The water pressure can be equated with the voltage (V). Both factors together decide how high the power is that is available for operating a waterwheel or motor.
Asynchronous motor (ASM): While the magnetic fields of the stator and rotor run in the same cycle with synchronous motors, the rotor with asynchronous motors (ASM) lags slightly behind. The very robust overall concept is a bit simpler and does not require complex controls or expensive permanent magnets. In return, however, the ASM lacks efficiency. It is also comparatively heavy and loud. But it has one big advantage: it can be deactivated at any time. If the current is switched off, it runs free-wheeling and does not consume any energy. The permanent magnets in the PSM, however, cannot be switched off. If the permanently excited motor does not actively drive the car, it works instead like a dynamo and recuperates permanently. However, this is not desirable when sailing smoothly on the motorway, which is why the ASM plays an important role, especially in expensive e-mobiles for long journeys. It is increasingly being used in a work-sharing combination with the PSM in order to be able to use the advantages of both technologies. Such cars then usually have all-wheel drive.
Bidirectional charging: Electric cars can not only fill up with electricity, they can also feed it back into the grid. This ability is known as bidirectional charging. In the future, e-mobiles are to become part of intelligent power grids ("smart grids") and temporarily store excess electricity from wind or solar systems and feed it back into the grid when required (vehicle 2 grid, V2C).
Board loader: The on-board charger in the electric car is necessary for charging alternating current - i.e. for refueling at a wallbox, normal charging station or socket. Its performance determines how quickly the battery is refilled. Anyone who drives their car regularly and is therefore often plugged into the socket should choose a model with a multi-phase charger. It works around two to four times as fast.
CCS: stands for "Combined Charging System" and is the German version of the fast charging plug, which is based on the common type 2 plug and adds two more poles (Combo 2). The CCS connector has established itself today with German and European manufacturers, among other things, the German Charging Column Ordinance (LSV) requires it to be available on new direct current fast charging columns. Tesla is now also equipping its cars in Europe with CCS sockets. The most important competitive standard is the Chademo system of a Japanese consortium, which is mainly supported by Japanese and French cars.
ChaoJi: is a charging standard jointly developed by the Chinese and Japanese to refuel e-cars with electricity almost as quickly as conventional vehicles with liquid fuel. Five minutes at the socket is enough for a range of 300 to 400 kilometers. So far, however, there are no cars available that could use the immense charging power of up to 900 kW. In the long term, the standard is intended to replace the Japanese Chademo plug as well as the Chinese GB / T technology.
Chademo: Abbreviation for “Charge de Move” and the name of the Japanese fast-charging connector system developed by the energy company Tepco and the car manufacturers Nissan, Mitsubishi, Toyota and Subaru. The typical charging power is 50 kW, but higher values are also possible. The competition standard is the German CCS system, both connector types are not compatible. The German charging station ordinance prescribes a CCS connection for direct current charging stations, but not a Chademo coupling.
Electric car: In the narrower sense, the name for a battery-powered e-car with or without a range extender. In a broader sense, fuel cell vehicles are also e-cars in terms of their type of drive. The federal government defines in the relevant laws and rules as follows: "An electric vehicle is a purely battery electric vehicle with a drive, in which all energy converters are exclusively electrical machines and all energy storage devices are exclusively electrically rechargeable energy storage devices." Although plug-in hybrids are excluded, In some statistics and studies, they are occasionally assigned to e-cars.
E-Mobility Provider (EMP): As is known from cell phones or the Internet, the direct contractual partner of the traction current customer is not necessarily the electricity manufacturer or infrastructure operator. Instead, there is often a service provider who intervenes and, for example, takes care of the authorization at the charging station via app or card, the handling of the refueling process and the subsequent billing. The best-known EMPs currently include "EnBW Mobility +", "Shell Recharge" and "Plugsurfing". In some cases, the companies also act as charging station operators.
Energy density: The energy density is the decisive factor for the weight of the battery. It describes the amount of energy that can be stored per unit mass or per unit volume of a battery, usually given in kJ or kWh per kilogram. The current average is 150 watt hours per kilogram. For comparison: the energy density of gasoline is 12.800 Wh / kg.
Solid battery: The solid-state or solid-state battery is the great hope of the electric car manufacturer. Compared to conventional lithium-ion technology, the new types of batteries are cheaper, more powerful and safer. The new battery replaces the previously required liquid electrolyte with a solid material. This increases the energy density, which means more range with the same installation space. At the same time, there is no need for cooling, which saves money and weight. In addition, the technology is considered to be safer, since stubborn fires cannot occur in the event of an accident. Solid-state batteries should go into series production as early as the middle of the decade.
Direct current (abbreviated to DC for "direct current"): the type of electricity that an e-car battery can store. For use in the electric motor, direct current must be converted into alternating current. If you fill up on the household network or at normal charging stations, the alternating current available there must be converted into direct current for the battery. The electric car itself has the necessary technology on board.
Induction charge: should make charging electric cars easier. Instead of connecting the car to a socket, it only has to be parked over a magnetic coil, which charges the battery without contact via a counterpart in the vehicle floor. In theory, the process also works on suitably equipped lanes while driving. The charging power is theoretically up to 11 kW in the range of normal AC charging stations. BMW is the first car manufacturer to offer an induction charging system for the plug-in hybrid version of the five-series. Other providers want to follow suit.
Kilowatt hour: a unit of measure for energy. With one kilowatt hour of electricity, a bucket of water can be boiled at room temperature. The batteries of normal electric cars currently have capacities between a good 20 kWh and 60 kWh, in individual cases around 100 kWh. Electricity consumption depends heavily on the model and driving style, but for normal e-mobiles it is currently usually in the range of 10 to 20 kWh per 100 kilometers. However, the theoretical range of the models' electric cars cannot be derived directly from the battery capacity (unlike conventional cars, where the range is determined by consumption and tank content), as the batteries must never be completely discharged.
Charging capacity: The charging power is the most important criterion for how long the electric car has to be connected to the power grid to fill up. A household socket provides a charging power of around 2,3 kW, a normal charging station or wallbox usually around 10 to 22 kW, and a fast charging station usually 50 kW to 100 kW. So-called ultra-fast charging stations come up to 350 kW. In order to charge an e-car battery with a capacity of 24 kWh, it would have to - in simplified terms - be plugged into the household socket for around eight hours, while it would be full after a few minutes on the ultra-fast charger. In practice, however, the loading times are longer. Among other things, because not every car can use the full power provided by the charging station and because the charging speed decreases as the battery level increases and the temperature increases. On the other hand, in consideration of the battery life, fast charging stations are usually only charged up to a fill level of 80 percent. In addition to the charging power, there is also a discharging power, which is usually higher; it usually corresponds to the drive power of an electric car.
Charging point: Many charging stations offer the option of charging several cars at the same time. One then speaks of several charging points. In official statistics, charging points are often counted, the number of columns is significantly lower. In many cases, the vehicles refueling at the same time have to share the charging power, which increases the waiting time.
Charging stations: There are basically two different types of charging stations: fast and slow. The latter work with normal alternating current (400 V, up to 63 A) and a charging power of usually 11 kW. If the charging power is above 22 kW, it is a fast charging station. There are also fast charging stations with direct current and high charging capacities from around 50 kW. In addition, the term “ultra-fast charging columns” has established itself, which is mostly used for systems with significantly more than 100 kW. In the private sector, so-called wall boxes are also used, which are usually offered in the 11 kW and 22 kW power levels.
Charging station operator: gladly abbreviated as CPO ("Charge Point Operator"). You are responsible for installing, maintaining and repairing the columns. As a rule, they are also the owners of the hardware, in other cases only tenants. Some CPOs also act as e-mobility providers (EMP), but then usually also have charging points from other operators in the network.
Charging station regulation: The LSV has been regulating the minimum technical requirements for charging stations in Germany since March 2016. It stipulates the so-called type 2 plug for normal charging stations, and the CCS system used by German manufacturers for direct current charging stations. In addition, it formulates comprehensive requirements for the operators of public charging points. In addition to public traffic areas, this also includes a large number of customer and company parking spaces. Inductive and wireless charging systems are not covered by the LSV.
Lithium Ion Battery: the current battery technology. Compared to the lead and nickel metal hydride batteries used previously, they offer a higher energy density. In addition, they have no memory effect. While their capacity is easily sufficient for cell phones and laptops today, they quickly reach their limits in cars. Another problem is the high price, which has recently fallen sharply. While it was around 2010 euros in the early 500s, it is now just under 100 euros per kilowatt-hour. The technology continues to offer development potential; The next possible development stage is a lithium iron phosphate battery, which, in addition to a higher energy density, should also offer significantly greater operational reliability.
Charging mode: Anyone who wants to get electricity in their e-car can use different sources. In order to bring order to the variety of socket outlets, four charging modes were defined years ago. The most important one is currently mode 3, which describes charging at special e-mobility sockets such as a charging station or wallbox. Mode 2 is when you use any other socket, such as the Schuko version in the garage or the blue socket on the campsite. Different cables with the appropriate designation are required for both modes, which is why the distinction still plays a role not only in expert circles, but also in everyday e-mobility. More of theoretical interest: Mode 4 describes charging at fast charging stations that have their own cables. Mode 1 means charging via a (spiral) cable permanently attached to the car. Today it hardly matters any more.
Mild hybrid system: Hybrid cars are also relatively expensive because their high-voltage components must be specially protected so that the occupants are not suddenly electrified in the event of an accident or malfunction. In the case of low-voltage or mild hybrid systems that only work with 400 volts instead of up to 48 volts, manufacturers could do without them. Because of their low cost, 48-volt hybrid systems are particularly suitable for small and compact vehicles. However, the low-voltage technology is less powerful than the high-voltage technology, so that the hybrid functions are usually limited to boosting when accelerating and starting off. Nevertheless, two-digit consumption advantages should be possible in percent compared to purely conventional drives. Some manufacturers also use the conventional 48-volt system for hybridization instead of a 12-volt network. Savings and costs are then slightly lower.
One-pedal driving: Some newer electric vehicles can be moved in everyday life with the accelerator pedal alone. If you kick it, the car drives, if you let it go, it decelerates. And much more so than a conventional vehicle in which the gas pedal is lifted. The e-mobile does not brake with the brake discs, but with the help of the on-board generator, which recovers braking power and stores it in the form of electricity in the battery. After getting used to it, “driving with a pedal” is often perceived as very pleasant. A brake pedal is still present, but is only used for particularly strong decelerations or in an emergency. However, not all manufacturers are currently following this approach.
Permanent excited synchronous machine (PSM): the most common type of electric motor in cars and in many household items today. "Permanently excited" means that so-called permanent magnets are used in the motor, for which expensive rare earths are required. This is not the case with the separately excited variant (FSM). There the magnetic field is temporarily generated by electricity - i.e. by an electromagnet. This is significantly cheaper in production than using permanent magnets made of rare earths, which is why this technology is particularly interesting for more price-sensitive e-cars. Or for those who do not depend on extreme driving performance.
Recuperation: The recovery of kinetic energy, which would otherwise be lost in the form of heat when braking, is not a privilege of the electric car. Cars with start-stop systems have been using the technology for years. While the electricity generated in conventional cars is used to relieve the generator / alternator, in electric cars it is used directly for the drive. However, only a relatively small part of the braking energy flows back into the battery as charging energy.
Range Extender: Usually a small internal combustion engine that doesn't use its power to drive the wheels, but rather an electricity generator that charges the batteries while driving. This means that further progress should be possible even after the current supply drawn from the socket has expired. However, this is only a kind of stopgap solution, as the engine is designed to be relatively economical, but in the end does not work very efficiently. For a long time, the BMW i3 relied on technology - but since battery capacities increased, the Munich-based company has been doing without the auxiliary engine. Mazda, on the other hand, wants to add an e-car with a range extender based on a rotary engine to its range for the first time.
Unbalanced load: means the uneven load on the power grid. This should be prevented in Germany by your unbalanced load regulation, which severely restricts single-phase charging of electric cars. Instead of the technically possible 7 kW, affected vehicles can legally only get 4,6 kW from the grid in this country. Three-phase charging e-cars, on the other hand, fill up with up to 22 kW, i.e. more than four times as fast. Different rules may apply in other countries.
Fast charging: The term is used differently by each manufacturer. In the relevant legal texts on e-mobility, one finds the definition that all charging processes with outputs above 22 kW could be referred to as fast charging. Another possible differentiation would be alternating current charging (AC, up to a maximum of 44 kW) versus direct current charging (DC, from 50 kW). In practice, the choice of definition hardly makes a difference, as there are virtually no AC charging points with more than 22 kW of power in this country. The number of suitable vehicles is also rather low. In addition to fast charging, the term ultra-fast charging (“High Performance Charging”, HPC) has recently become established. This mostly refers to the DC charging stations of the Ionity operator consortium, which deliver up to 350 kW - currently the top value in Europe.
Connector types: Almost every electric car can be charged at a normal household socket. In addition, it will be difficult. The EU has decided on the so-called Meneckes Type 2 plug as the standard on public charging stations, the plug is already supplied with most electric cars on the charging cable. In other European countries, however, other connector types are currently in use. Even in this country, the DC plugs for fast charging stations are inconsistent. While the German manufacturers rely on the CCS system, the Japanese and French use the Chademo standard for their models. The types are not compatible. Only CCS couplings are required by law in Germany.
Electricity supplier: it supplies the charging stations with electricity. Only one supplier can be active for each pillar. The company is not necessarily also the operator of the charging station (CPO) or e-mobility provider (EMP).
Super capacitors: In contrast to batteries, supercapacitors store energy electrically instead of electrochemically. As a result, they can be charged more quickly and also release their energy again quickly. While supercapacitors have been in use for years in flash units in photo cameras, for example, they are still relatively new in automotive engineering. Mazda uses the electricity storage system to regenerate braking force, for example; in Formula One, they are already part of the hybrid system and provide electricity for acceleration. Volvo is currently experimenting with manufacturing entire vehicle parts from supercapacitors, which can then be used in cars with virtually no space requirements. However, supercapacitors can charge quickly, but not very much. Their energy density is extremely low. As the sole source of energy for vehicle propulsion, they are hardly an option; rather, in the future, they will probably serve as a supplement to normal batteries - especially for braking energy recovery.
Plug-in hybrid: a kind of part-time electric car mixed with a hybrid vehicle. There is usually a comparatively small battery on board that can be charged at the socket and enables a purely electric range of around 50 kilometers. The hybrid car then continues to drive. The plug-in hybrid drive is regarded as a bridging technology up to the introduction of high-performance batteries, which also enable pure electric cars to have a range suitable for long journeys. Not least, they are of interest to car manufacturers because they achieve very good CO2 values in the NEDC consumption cycle, because the battery is started with a full battery, but any carbon dioxide emissions in the production of the electricity required are not taken into account. With similar prices, they are more attractive to customers than pure electric cars because the range problem is bridged with the internal combustion engine.
Wheel hub motor: an electric motor that is not in the center of the vehicle, but directly on the wheel. It was already used in e-cars like the Lohner-Porsche at the beginning of the 20th century, but has now disappeared from mass-produced cars, partly because its high weight in an unfavorable place causes problems in driving comfort and also the space for the steering mechanism is tight. This is currently not compensated for by the numerous advantages. These include, among other things, the gain in installation space in the body, the possible omission of drive shafts and the gain in driving dynamics and safety through the possible wheel-selective control of the drive force.
Supercharger: Tesla's free charging stations for own brand vehicles. In Europe, the Tesla system initially used a modified type 2 plug, which, unlike its counterpart used by other brands, also allows charging of direct current with up to 250 kW. In the meantime, pillars and vehicles are being converted to the CCS standard. The batteries of Model S, Model X and Co. can be charged on superchargers within a few minutes - previously generally free of charge, now depending on the model, billing is based on minutes or kilowatt hours (33 cents). According to its own information, Tesla operates more than 1.800 charging stations in Europe with a total of almost 16.000 charging points, mostly on major thoroughfares, in order to enable its customers to travel longer in electric cars. Vehicles from other brands cannot use Superchargers, but Tesla models can refuel at Type 2 and, if necessary, CCS charging stations.
Ultra fast charging: Conventional fast charging is not enough to make the electric car really suitable for long journeys. The German car manufacturers therefore rely on ultra-fast charging with up to 350 kW via the CCS plug. A corresponding network of stations is already being built by the joint venture company Ionity along the European motorways. Audi, BMW, Daimler, Ford, Porsche and Hyundai-Kia are currently involved in the infrastructure project, and other manufacturers have been invited. So far, however, there has been a lack of cars that can access the full charging power of the ultra-fast stations.
Temperature management: Batteries get hot under prolonged load. This not only affects the power output of the energy storage systems, but also their ability to store electricity. After a long journey or at high temperatures, it can happen that the full power can no longer be accessed at the charging stations. This phenomenon has become known under the name "Rapidgate". Some, but by no means all, electric vehicles therefore have a cooling system that keeps the battery at the optimum temperature. Other manufacturers are trying to get the problem under control with intelligent charging software. Anyone who drives a lot or is dependent on fast charging should still choose a model with active cooling.
Vampire losses: All electric cars suffer from the phenomenon of self-discharge. This is due on the one hand to undesirable chemical side reactions within the cells, which cannot be completely switched off even with the best batteries, and on the other hand to the battery monitoring systems, which also consume electricity when stationary. However, due to errors in production, the losses can be particularly severe in individual cases. How long it takes before a parked electric car runs out of power depends on many factors. In addition to the fill level and the basic quality of the respective battery as well as the efficiency of the cell monitoring, the outside temperature also has an influence. Leaving an almost empty electric car standing in the blazing sun for weeks is definitely not a good idea.
Consumption: The power consumption is determined with the same laboratory test as that of a diesel or gasoline engine. However, it is not stated in liters per 100 kilometers, but generally in kilowatt hours per 100 kilometers. The CO2 emissions are given as zero, the emissions from electricity production are not taken into account.
Volt: is the unit of electrical voltage (V). If you imagine the flow of current as the flow of water through a pipe, the voltage corresponds to the water pressure. The current strength (A) can be equated with the pipe diameter. Both factors together decide how high the performance is. Ultimately, then, how much energy is available to operate a waterwheel or motor.
Wallbox: a permanently installed charging station for e-mobiles, usually intended for the garage at home. Wallboxes are available in different power levels between 3,7 and 22 kW, the most common are those with 11 kW. They are usually sufficiently fast and do not require approval from the network operator. Since autumn 2020, the federal government has been funding the purchase and installation of a wallbox with 900 euros. Applications and a list of the funded models can be found on the website of the Kreditanstalt für Wiederaufbau (KfW). In addition to the fixed models, there are also mobile chargers with the same function; they can be carried in the car and connected to any power source while en route, but there is usually no funding.
Alternating current (abbreviated to AC for "alternating current"): normal household electricity. At the building it comes in its three-phase version as a so-called "three-phase current", in the kitchen it is used to connect the electric stove. Single-phase alternating current occurs in the Schuko socket. Both "types" can be filled up by the electric car, but must be converted into direct current on board in order to be stored in the battery.