Battery electric vehicle

In an electric vehicle, the battery, or rather the battery pack, plays a decisive role. This component determines, among other things, the range, charging time, weight and price of an electric vehicle. In this article, we'll walk you through everything you need to know about batteries.

Let's start with the fact that electric vehicles use lithium-ion batteries. Batteries of this type can also be found in mobile phones and laptops. There are different types of lithium-ion batteries that process different raw materials such as cobalt, manganese or nickel. The advantage of lithium-ion batteries is that they have a high energy density and a long service life. The disadvantage is that it is not possible to use the full power. Discharging the battery completely is harmful. These issues will be given more attention in the following paragraphs.

Unlike a phone or laptop, electric vehicles have a rechargeable battery made up of a set of cells. These cells form a cluster that can be connected in series or in parallel. The battery takes up a lot of space and weighs a lot. To distribute the weight as much as possible across the vehicle, the battery is usually built into the bottom plate.

Емкость

Battery capacity is an important factor in the performance of an electric vehicle. The capacity is specified in kilowatt-hours (kWh). For example, the Tesla Model 3 Long Range has a 75 kWh battery, while the Volkswagen e-Up has a 36,8 kWh battery. What exactly does this number mean?

Watt - and therefore kilowatt - means the power that a battery can produce. If a battery delivers 1 kilowatt of power for an hour, that's 1 kilowatt.hour energy. Capacity is the amount of energy a battery can store. Watt-hours are calculated by multiplying the number of amp-hours (electrical charge) by the number of volts (voltage).

In practice, you will never have full battery capacity at your disposal. A completely discharged battery - and therefore using 100% of its capacity - is detrimental to its lifespan. If the voltage is too low, the elements may be damaged. To prevent this, the electronics always leave a buffer. Full charge also does not contribute to the battery. It is best to charge the battery from 20% to 80% or somewhere in between. When we talk about a 75kWh battery, that's full capacity. Therefore, in practice, you always have to deal with less usable capacity.

temperature

Temperature is an important factor affecting battery capacity. A cold battery leads to a significant reduction in capacity. This is because the chemistry in the battery doesn't work as well at low temperatures. As a result, in winter you have to deal with a smaller range. High temperatures also negatively affect performance, but to a lesser extent. Heat has a major negative effect on battery life. Thus, cold has a short-term effect, while heat has a long-term effect.

Many electric vehicles have a Battery Management System (BMS) that monitors temperature, among other things. The system often also actively intervenes through heating, cooling and / or ventilation.

lifespan

Many people wonder what is the battery life of an electric vehicle. Since electric vehicles are still relatively young, there is no definitive answer yet, especially when it comes to the latest batteries. Of course, this also depends on the car.

The service life is partly determined by the number of charge cycles. In other words: how often the battery is charged from empty to full. Thus, the charging cycle can be divided into several charges. As stated earlier, it is best to charge between 20% and 80% each time to extend battery life.

Excessively fast charging is also not conducive to extending battery life. This is due to the fact that during fast charging, the temperature rises greatly. As already mentioned, high temperatures negatively affect battery life. In principle, vehicles with an active cooling system can resist this. In general, it is recommended to alternate fast charging and normal charging. It's not that fast charging is bad.

Electric vehicles have been on the market for quite some time now. So, with these cars, you can see how much the battery capacity has decreased. Productivity typically decreases by about 2,3% per year. However, the development of battery technology does not stand still, so the degree of degradation is only decreasing.

With electric vehicles that have traveled many kilometers, the drop in power isn't all that bad. Teslas, which have driven over 250.000 90 km, sometimes had more than XNUMX% of their battery capacity left. On the other hand, there is also Teslas where the entire battery has been replaced with less mileage.

production

The production of batteries for electric vehicles also raises questions: how environmentally friendly is the production of such batteries? Are unwanted things happening during the production process? These issues are related to the composition of the battery. Since electric vehicles run on lithium-ion batteries, lithium is an important raw material anyway. However, several other raw materials are also used. Cobalt, nickel, manganese and / or iron phosphate are also used depending on the battery type.

Environment

The extraction of these raw materials is harmful to the environment and damages the landscape. In addition, green energy is often not used in production. Thus, electric vehicles also affect the environment. It is true that battery raw materials are highly recyclable. Discarded batteries from electric vehicles can be used for other purposes as well. Read more on this topic in the article on how environmentally friendly electric vehicles are.

Working conditions

From the point of view of working conditions, cobalt is the most problematic raw material. There are concerns about human rights during mining in the Congo. They talk about exploitation and child labor. By the way, this is not only related to electric vehicles. This issue also affects phone and laptop batteries.

Costs

Batteries contain expensive raw materials. For example, the demand for cobalt, and with it the price, has skyrocketed. Nickel is also an expensive raw material. This means that the cost of producing batteries is quite high. This is one of the main reasons why electric vehicles are more expensive compared to their petrol or diesel equivalent. It also means that a model variant of an electric car with a larger battery often becomes much more expensive right away. The good news is that batteries are structurally cheaper.

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Accupercentage

The electric car always indicates what percentage of the battery charge. It is also called Charge state called. An alternative measurement method is Discharge depth... This shows how discharged the battery is, not how full it is. As with many gasoline or diesel vehicles, this often translates into an estimate of the remaining mileage.

The car can never tell exactly what percentage of the battery charge, so it is advisable not to tempt fate. When the battery is nearing low, unnecessary luxury items such as heating and air conditioning will be shut off. If the situation gets really dire, the car can only go slowly. 0% does not mean a completely discharged battery due to the aforementioned buffer.

Load

The charging time depends on both the vehicle and the charging method. In the vehicle itself, the battery capacity and the charging capacity are decisive. The battery capacity has already been discussed before. When power is expressed in kilowatt hours (kWh), the charging capacity is expressed in kilowatts (kW). It is calculated by multiplying the voltage (in amperes) by the current (volts). The higher the charging capacity, the faster the vehicle will charge.

Conventional public charging stations are charged with either 11 kW or 22 kW AC. However, not all electric vehicles are suitable for 22 kW charging. Fast charging chargers are charged with constant current. This is possible with a much higher lifting capacity. Tesla Superchargers Charge 120kW and Fastned Fast Chargers 50kW 175kW. Not all electric vehicles are suitable for fast charging with a high power of 120 or 175 kW.

Public charging stations

It is important to know that charging is a non-linear process. Charging at the last 20% is much slower. This is the reason why charging time is often referred to as charging to 80%.

Loading time depends on several factors. One factor is whether you are using single-phase or three-phase charging. Three-phase charging is the fastest, but not all electric vehicles are suitable for this. In addition, some houses only use a single-phase connection instead of a three-phase one.

Regular public charging stations are three-phase and are available in 16 and 32 amps. Charging (0% to 80%) of an electric vehicle with a 50 kWh battery takes approximately 16 hours at 11 A or 3,6 kW pile charging stations. It takes 32 hours with 22 amp charging stations (1,8 kW poles).

However, it can be done even faster: with a 50 kW fast charger, it will take just under 50 minutes. Nowadays there are also 175 kW fast chargers, with which a 50 kWh battery can be charged even up to 80% in XNUMX minutes. For more information on public charging stations, see our article on charging stations in the Netherlands.

Charging at home

It is also possible to charge at home. Slightly older houses often do not have a three-phase connection. Charging time, of course, depends on the current strength. At a current of 16 amperes, an electric car with a 50 kWh battery charges 10,8% in 80 hours. At a current of 25 amperes, this is 6,9 hours, and at 35 amperes, 5 hours. The article on getting your own charging station goes into more detail about charging at home. You may also ask: how much does a full battery cost? This question will be answered in the article on the costs of electric driving.

Summing up

The battery is the most important part of an electric vehicle. Many of the disadvantages of an electric vehicle are associated with this component. Batteries are still expensive, heavy, temperature sensitive and not environmentally friendly. On the other hand, degradation over time isn't that bad. What's more, batteries are already much cheaper, lighter and more efficient than they used to be. Manufacturers are hard at work on the further development of batteries, so the situation will only get better.