How do electric cars work? An in-depth look
How does an electric car actually work and what are the technical peculiarities? In this blog post, we go into detail about the technology and functionality of electric vehicles and shed light on all the important aspects.
Key facts about how electric cars work
Electric cars have a much simpler design than combustion engines: electric motor, battery, power electronics, transmission and charging port are the main components that work together perfectly.
The electric motor is the heart of the drive. It converts electrical energy into motion, offers full torque from the first revolution and achieves an efficiency of up to 95%.
The battery is the energy storage of the electric car. Powerful lithium-ion batteries are usually used, whose capacity determines the range. Intelligent charging and recuperation increase efficiency.
Power electronics and charging technology are crucial for performance and suitability for everyday use. They control the flow of energy, enable fast charging and protect the components from overloading.
Basic structure of an electric car
In contrast to combustion engines, the powertrain of an electric car consists of significantly fewer components. These components work closely together to power the electric car efficiently and reliably. The main ingredients are:
- Electric motor: The heart of the drive, converts electrical energy into kinetic energy.
- Battery (high-voltage battery): Stores the electrical energy and supplies the motor.
- Power electronics: Controls and regulates the flow of energy between the battery and the motor.
- Transmission: Transfers the power of the engine to the drive axles (often single-stage).
- Charging port: Allows the battery to be charged at charging stations or sockets.
Skateboard architecture in construction
Many electric cars use a so-called "skateboard architecture" in their construction. The heavy components such as the battery and electric motor are arranged flat in the underbody of the vehicle. This ensures a low centre of gravity and optimal weight distribution, which improves driving dynamics and stability. In addition, this design offers more flexibility in the design of the body and the interior.
- Small car: From about 20,000 euros, ideal for city traffic
- Mid-range: Average 30,000 to 50,000 euros, good for families
- Luxury class: Often 80,000 to 100,000 euros, offers luxury and range
How the electric motor works
The principle of the electric motor is based on the interaction of magnetic fields. Inside the motor are two main components: the fixed stator and the rotating rotor. The stator consists of coils through which alternating current flows. This creates electromagnetic fields. The rotor is equipped with permanent magnets. The interaction of the magnetic fields of the stator and rotor creates a force that causes the rotor to rotate. The power electronics control the frequency and strength of the alternating current, thus regulating the speed and torque of the motor. Electric motors can develop their maximum torque from a standstill, which ensures direct response and powerful acceleration.
Advantages of electric motors
- High efficiency (up to 70%)
- Full power from the first revolution
- Low noise and vibration-free
- Low-maintenance and durable
- Due to the direct power transmission, most electric cars also do not have a manual transmission, which increases driving comfort.
Comparison of efficiency and efficiency
Electric motors have a significantly higher efficiency than combustion engines. While modern gasoline and diesel engines convert a maximum of 40% of the energy used into motion, electric motors achieve efficiencies of up to 70%. This means that electric cars use the available energy much more efficiently and thus have fewer energy losses.
The battery as energy storage
The battery is, so to speak, the tank of the electric car. Lithium-ion batteries, which consist of many individual cells, are usually used here. Each cell contains an anode (negative electrode), a cathode (positive electrode), and an electrolyte. When discharging, the lithium ions migrate from the anode to the cathode, releasing electrons that flow to the motor via an external circuit.
When charging, the process is reversed: the lithium ions migrate back to the anode, and the electrons are stored in the cell again. The capacity of the battery, measured in kilowatt hours (kWh), determines the range of the electric car. The higher the capacity, the more energy can be stored and the further you can get with one charge.
Important factors in the battery
- Gross and net capacity (usable capacity)
- Charging speed and behavior
- Temperature management (cooling and heating)
- Durability and ageing
Battery production is currently still complex and expensive, but the technology is constantly evolving. Advances in energy density, fast-charging capability and service life are making electric cars more and more suitable for everyday use.
Difference between gross and net capacity
When it comes to the capacity of an electric car battery, a distinction is made between gross and net capacity. The gross capacity indicates the total amount of energy that can theoretically be stored. However, not all of this can be used, as some of it serves as a buffer to protect the battery and increase its lifespan. The amount of energy that can actually be used is referred to as net capacity and is usually 10-20% below gross capacity.
Influence of cold on battery performance
Low temperatures have a negative impact on the performance and range of electric car batteries. In the cold, the chemical reactions in the cells slow down, reducing the available capacity. In addition, part of the energy is needed to heat the battery and the interior, which also eats away at the range. However, modern electric cars have efficient heat pumps and insulation that mitigate this effect.
Charging technology
- AC charging (alternating current): This is done via the on-board charging electronics, which convert the alternating current into direct current. This is common at domestic wallboxes or public AC charging stations. Charging power usually between 3.7 and 22 kW.
- DC-Laden (Gleichstrom): Der Gleichstrom wird direkt in die Batterie eingespeist, die Umwandlung erfolgt in der Ladesäule. Ermöglicht hohe Ladeleistungen bis zu 350 kW und damit kurze Ladezeiten. Vor allem an Schnellladestationen entlang von Autobahnen zu finden.
Ladekabel und Steckertypen für Elektroautos
Um Ihr Elektroauto an öffentlichen Ladestationen oder zu Hause aufladen zu können, benötigen Sie ein geeignetes Ladekabel. Dieses ist entweder bereits im Lieferumfang Ihres Fahrzeugs enthalten oder fest an der Ladestation installiert. Es gibt verschiedene Steckertypen, die je nach Fahrzeug und Ladestation variieren können. Daher ist es wichtig, dass der Ladeanschluss Ihres Elektroautos mit dem Stecker der Ladestation kompatibel ist. Andernfalls benötigen Sie einen passenden Adapter.
In Deutschland und der Europäischen Union hat sich der sogenannte Typ-2-Stecker, auch bekannt als Mennekes-Stecker, als Standard etabliert. Seit 2013 gilt er EU-weit als Norm für öffentliche Ladestationen. Der Typ-2-Stecker ermöglicht das dreiphasige Laden und kann mit dem CCS-Stecker (Combined Charging System) erweitert werden. Dieser wird auch als “Combo-2-Stecker” bezeichnet und verfügt über zwei zusätzliche Ladekontakte. Durch diese Erweiterung sind Schnellladevorgänge mit Gleichstrom (DC) und Ladeleistungen von bis zu 300 Kilowatt und mehr möglich.
To start charging at public charging stations, you need a charging card or a charging app in addition to the right charging cable. With these, you can unlock the charging station, start the charging process and then pay. You can get the charging card from your electricity provider or a third-party provider, while the charging apps are usually available free of charge in the usual app stores. When buying an electric car, pay attention to which types of plugs the vehicle supports and which charging cables are included in the scope of delivery. This ensures that you can easily charge your electric car at the various charging stations and are prepared for any situation
Recuperation
A special feature of electric cars is recuperation. When braking or driving downhill, the kinetic energy generated can be captured and thus converted into electrical energy and fed back into the battery. This process can significantly increase the efficiency of the electric vehicle and increase its range.
The principle of recuperation is simple: as soon as the driver takes his foot off the accelerator pedal or brakes, the electric motor takes over the function of a generator. Instead of powering the car, it converts the kinetic energy into electricity, which flows directly into the battery and recharges it. Depending on the driving situation and the settings of the recuperation system, a considerable proportion of the braking energy can be recovered and stored. Especially in urban stop-and-go traffic or on routes with many gradients, recuperation shows its best side. Here, the recovered energy can improve the range by up to a fifth. At the same time, the conventional brakes are protected, as the electric motor takes over a large part of the braking process.
Current electric cars often offer several levels of recuperation, between which the driver can choose depending on his preference and driving conditions. In the highest level, so-called "one-pedal driving", the vehicle can be braked to a standstill by recuperation alone, without having to press the brake pedal.
The role of power electronics
The power electronics are the link between the battery and the electric motor. It has several important tasks:
- Conversion of direct current from the battery into alternating current for the motor
- Voltage and frequency control to control speed and torque
- Energy recovery during braking (recuperation)
- Battery and motor protection and monitoring functions
Modern power electronics work very efficiently to maximize the range of the electric car. It uses high-performance semiconductors such as IGBTs (Insulated-Gate Bipolar Transistors) or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) to precisely switch high currents and voltages. In addition, the power electronics continuously monitor the condition of the battery and motor. It protects the battery from overcharging, over-discharging and overheating by limiting the charge or discharge current when needed. The motor is also protected from overloading, for example by limiting torque at excessively high temperatures.
Transmissions in electric cars
In contrast to combustion engines, electric motors often do not require a multi-speed manual transmission. The reason for this is the torque characteristics of electric motors: they offer full torque from the very first revolution and can work efficiently in a wide speed range.
Therefore, many electric cars rely on a single-stage transmission with a fixed ratio. It converts the high speed of the engine into the required lower speed at the drive wheels. The gear ratio is chosen in such a way that a compromise between acceleration and top speed is achieved.
Some manufacturers are also experimenting with multi-speed transmissions to further increase efficiency. Two gears are usually used: a short gear for powerful acceleration and a long gear for efficient driving at high speeds. The gear shift is automatic and imperceptible to the driver.
Range and suitability for everyday use
The range is a decisive factor for the suitability of electric cars for everyday use. It depends on many factors, including:
- Battery capacity
- Drive efficiency
- Driving style and speed
- Outdoor temperature and weather conditions
- Payload and route profile
- Use of heating or air conditioning
Modern electric cars already achieve ranges of 400 to over 500 kilometers in the WLTP cycle. Thanks to steadily growing battery capacities and an expansion of the charging infrastructure, even longer distances are no longer a problem. Nevertheless, the use of an electric car requires some rethinking and planning.
Charging times are longer than refueling a combustion engine, and charging stations are not available everywhere. But with the right preparation, predictive route planning and adaptation of the driving style, the range can be optimised and everyday life can be mastered electrically without any problems.
Tips for optimizing your reach
The range is a decisive factor for the suitability of electric cars for everyday use. In addition to the battery capacity and the efficiency of the drive, driving style and environmental conditions also have a major influence. With these 7 tips, the reach can often be significantly increased:
- Drive with foresight and evenly, avoid frequent acceleration and braking
- Use recuperation to recover braking energy
- Reduce speed, as energy consumption increases disproportionately with speed
- Use unnecessary electrical consumers such as air conditioning or seat heating sparingly
- Preheat or cool the battery before starting the journey while the car is still connected to the charging station
- Check tyre pressure regularly, as too low pressure increases rolling resistance
- Avoid unnecessary ballast and remove roof racks when they are not needed
Many modern electric cars also offer eco driving programs and range assistants that help the driver to drive efficiently. By adjusting the engine power, air conditioning and recuperation level, the range can often be increased by 10-20%. With increasing experience, many electric car drivers develop a feel for efficient driving and can make optimal use of the advantages of electric mobility.
Advantages and disadvantages of electric cars compared to combustion engines
Advantages of electric cars
- Zero emissions: Electric cars do not emit any pollutants while driving and thus contribute to improving air quality.
- Government subsidies: When buying an electric car, buyers can benefit from subsidies and tax advantages.
- Driving pleasure: Electric motors offer direct response and powerful acceleration.
- Low noise: Electric cars are significantly quieter than combustion engines, which increases driving comfort and reduces noise pollution.
- Lower operating costs: Electricity is usually cheaper than gasoline or diesel, and there are no costs for oil changes and other maintenance work.
Disadvantages of electric cars
- Charging infrastructure: Although the network of public charging points is growing, it is not yet as dense as the network of filling stations.
- Charging times: Charging the battery takes significantly longer than refueling a combustion engine, even at fast-charging stations.
- Higher acquisition costs: Electric cars are usually more expensive than comparable combustion engines, even if prices are falling due to economies of scale and technological advances.
- Limited range: Despite increasing battery capacities, electric cars have a shorter range than combustion engines, which is an obstacle for some users.
- Life cycle assessment: The production of batteries is energy-intensive and requires the extraction of rare raw materials, which affects the overall life cycle assessment of electric cars.
Overall, electric cars offer many advantages such as zero emissions, lower operating costs and government subsidies. However, this is also offset by disadvantages such as higher acquisition costs, limited range and a still patchy charging infrastructure. However, as technology advances and the charging infrastructure expands, many of these disadvantages are likely to become less important in the future.
Faq
How do electric cars work – A conclusion
Electric cars are fascinating high-tech vehicles that enable comfortable, quiet and emission-free mobility through the perfect interaction of electric motor, battery, power electronics and charging technology. At the heart of this is the efficient and powerful electric motor, which is precisely controlled by the power electronics. The battery as an energy storage unit plays a key role in determining the range, which can be optimised through intelligent charging and an anticipatory driving style.
With growing ranges, faster charging times and an increasing charging infrastructure, electric cars are becoming more and more suitable for everyday use and a real alternative to combustion engines. By understanding how it works and making some simple behavioral adjustments, efficiency can be further increased and the full potential of electric cars can be exploited. So nothing stands in the way of an electric future on our roads.
How long does it take to charge an electric car?
The charging time depends on various factors, such as the capacity of the battery, the charging power and the state of charge. At a domestic socket (2.3 kW), charging can take 8-16 hours, depending on the model. At a wallbox (3.7-22 kW), the time is reduced to 2-8 hours. At fast-charging stations (up to 350 kW), up to 80% of the capacity can often be charged in less than an hou
How far can I get with one charge?
The range of modern electric cars is usually between 200 and 600 kilometers, depending on the model and battery capacity. However, influencing factors such as driving style, speed, outside temperature and payload can reduce the actual range. The range can often be optimised through anticipatory driving and recuperation.
How long does the battery of an electric car last?
The battery life depends on various factors, such as charging cycles, temperature management and condition. Most manufacturers give a warranty of 8 years or 160,000 kilometers on the battery. Experience shows that even after that, more than 70% of the original capacity is often still available. The service life can be extended by gentle charging and avoiding deep discharge.
Are electric cars really more environmentally friendly than combustion engines?
Electric cars do not emit any pollutants locally, making them a clean alternative in metropolitan areas. However, the overall life cycle assessment depends on the origin of the charging current. Green electricity from renewable sources makes electric cars a real climate protector. But even with the German electricity mix, they usually perform better than combustion engines. However, the extraction of raw materials for the batteries should be viewed critically.
How much does it cost to charge an electric car?
Charging costs depend on the price of electricity and the capacity of the battery. If you charge at home, you pay the normal household electricity price (approx. 30-35 cents/kWh). With a capacity of 40 kWh, this results in costs of 12-14 euros for a full charge. At public charging stations, fees for the charging station or the provider are often added. Overall, however, the operating costs are usually significantly lower than with combustion engines.
Can I also charge an electric car in my own garage?
Yes, charging in your own garage is possible and even recommended. For regular charging, a wallbox with a higher charging capacity makes sense. It is connected to the house connection by an electrician. Professional installation and sufficient protection are important. Special regulations apply to tenants and apartment owners regarding approval and cost allocation.
source : How do electric cars work? An in-depth look (chargehere.de)