The electric car battery is an example of using a commonly used technology in a completely new way. But what is it? What capabilities does it have? Is it really environmentally friendly? In this text, we answer more than just these questions. You will also find out how long the warranty lasts and the price of electric car batteries.
What is an electric car battery?
A battery for an electric car is a galvanic cell, i.e. a system made of two electrodes (a cathode and an anode) that stores and releases electrical energy. Such circuits are used to power various types of equipment, e.g. smartphones, laptops, but also cars. The battery can be recharged repeatedly with electricity.
Galvanic cells also include batteries. Unlike batteries, however, it is not possible to recharge it. Once the stored energy is exhausted, the battery must be replaced. The cells used in hybrid and electric cars are therefore not batteries in the strict sense of the word, but batteries. Nevertheless, due to the popularity of the term "electric car battery", it will also be used in this text.
Battery types for the electric car
The batteries used by automotive companies are predominantly lithium-ion and nickel-hydride cells. Their different properties have led to their use in different types of electric cars.
Lithium-ion batteries have a good weight-to-energy ratio. This means that, with their relatively low weight, this type of battery is able to provide a satisfactory vehicle range, which is typically 300-400 km on a single charge. This type of battery is also characterised by a slow progression of the so-called memory effect, i.e. a decrease in battery capacity after many charging cycles. For this reason, they are used not only in fully electric cars, but also in plug-in hybrids (PHEVs).
Nickel metal hydride cells, on the other hand, are characterised by a stronger memory effect. In this case, regular charging is a must in order to maintain optimum battery performance. But how do you ensure this regular charging? By converting thermal energy into electrical energy. This is possible through energy recovery during braking - a process known as recuperation. This ensures that the battery has a steady increase in power and the car owner does not have to remember to top it up. This is precisely the reason why these batteries are fitted to conventional hybrids (HEVs) - i.e. combustion cars in which electric power is only used auxiliary.
Electric car battery - battery life
The lifespan of electric vehicle batteries is usually set at around eight years. After this time, the capacity of the batteries drops to around 60% of the initial value. For example, the warranty provided by the Tesla brand for the lithium-ion battery is precisely 8 years. The battery in Nissan, Renault and Hyundai vehicles can also be replaced after the same period of time.
However, manufacturers' offers are not only linked to the lifetime of the cars. Replacement of the cell also depends on the number of kilometres driven, making it possible to take advantage of the service in advance. Each concern sets its own ceiling; usually 160,000 km. So if you drive this distance before the number of years specified by the manufacturer has elapsed, you will be entitled to early battery replacement.
How are batteries selected for electric cars?
Batteries for an electric car are designed taking into account the weight, planned range and engine power of the vehicle. The same principle applies here as for cells used in electronic devices: the larger the battery in a device, the longer it lasts. However, the higher performance comes at the price of the higher weight and size of the cell. It also takes longer to recharge. Examples include two high-end electric car models: Hummer EV Edition 1 and Tesla Model 3 Performance. The battery pack of the electric version of the iconic off-roader has been adapted for a 983 hp engine, and the weight of the car without batteries is 2.8 t. Such weight and power translate into a high energy consumption of 40 kWh for every 100 km driven.
How to ensure at least a decent range in such a colossus? Simple: use an extra-large battery pack. The capacity of the cell used in the electric Hummer is 250 kWh, which translates to a maximum of 530 km of driving on a single charge. However, this has an impact on weight. The car's battery weighs as much as 1.3 t and the entire car weighs 4.1 t. The batteries used in the electric Hummer are therefore a mere 500 kg lighter than the entire Tesla Model 3 Performance. The car weighs around 1.8 t and its engine output is 224 hp. The much lighter car also does not consume as much energy as the Hummer - as the Tesla "burns" 20 kWh per 100 km. This made it possible to use an 80 kWh battery weighing 480 kg to achieve a range of 547 km.
What causes electric car batteries to fail?
The lithium-ion batteries for an electric car are most influenced by three factors. One of them - the age of the vehicle - is beyond the driver's control. However, the damage caused by the other two can be reduced. These are the temperature of the air surrounding the cell and its correct operation. The first cause of the increasingly shorter range of a car is related to the memory effect already mentioned. As the vehicle gets older and more charges are made, the capacity of the vehicle becomes shorter and shorter.
The cooling system is very important here. Modern electric batteries are cooled using fluid pumped from the tubes into the cells. The batteries of early electric car models did not have an active cooling system. This had a huge impact on the durability of the cells. This is because passive cooling through heat dissipation is not efficient enough. The battery degraded more quickly and therefore had to be recharged more frequently. Regular topping up of the cooling liquid must therefore be remembered. Proper charging also helps to keep the battery in good condition. Battery condition is negatively affected by topping up with fast chargers. Frequent charging will also shorten the service life.
How are electric car batteries serviced and repaired?
The increasingly popular electric cars are now also appearing on the aftermarket. For this reason, there are already quite a few service centres for this type of car, which, like authorised workshops, can carry out repairs - including the most important one, which is replacing the battery in an electric car. However, a better idea would be to buy a new car. Why? The cost of replacing the battery makes the repair uneconomic. With a new car, the buyer gets the aforementioned guarantee of a replacement cell, the price of which is extremely high (when we are talking about the cell as a spare part).
How much does an electric car battery cost?
New batteries for electric cars cost up to several tens of thousands of zlotys. In the case of Nissan's popular Leaf model, the cost of these key parts is close to PLN 60-70 thousand. However, these are not the most expensive batteries for electric cars. The price of a new cell for the Tesla Model S is as high as PLN 80 thousand. In premium cars, the cost of a battery can exceed PLN 100 thousand. Replacing the battery in the luxury electric car Jaguar I-Pace is valued at as much as PLN 160 thousand.
Batteries for electric cars and car fires
Vehicle cell fires are one of the arguments cited as an example of the dangers of e-motorisation. Battery ignitions do indeed happen, even leading to recalls of entire production batches of vehicles. An example of this is GM informing Chevrolet Bolt owners that faulty batteries must be replaced. 
However, electric cars cannot be considered more dangerous than combustion cars. In fact, regulations have been developed within the European Union that clearly define battery endurance standards. The battery pack must be able to withstand, among other things, contact with fire and resist overcharging. The cells must also be able to withstand short circuits, crushing and sudden temperature changes. Furthermore, cars with internal combustion engines are not entirely safe either. They use another flammable energy source for propulsion. This is, of course, conventional fuel (petrol, diesel or LPG).
Are batteries for electrics green?
Environmental protection through electric cars is one of the most controversial aspects related to electromobility. Indeed, there is no clear answer to this question. There is no doubt that driving an electric car itself is environmentally friendly. Due to the lack of an internal combustion engine, the production of smog, which is becoming an increasing threat to the health of inhabitants of major metropolitan areas around the world, is reduced.
Unfortunately, emission-free driving does not go hand in hand with an equally environmentally friendly manufacturing process for this type of vehicle. The production of batteries for electric cars requires the exploitation of deposits of rare elements and minerals: lithium, cobalt, graphite and nickel. Each of these is essential for the construction of batteries. Their extraction leads to the consumption of large quantities of potable water, degrading the environment, leading to the release of harmful dusts such as sulphur dioxide, among others. Moreover, the working conditions in the mines extracting these metals are often scandalous. Electric motoring is also not helped by the fact that it is nowadays environmentally unfriendly... to generate electricity itself. The vast majority of energy is generated in coal-fired or nuclear power plants that produce harmful greenhouse gases or radioactive waste.
Electric cars are changing the face of motoring. Although the technology is still in its infancy and the price of batteries for electric cars remains very high, in future electric cars will probably be as common as combustion vehicles. Despite all the disadvantages of 'electrics', there is every indication that the future belongs to them.
