How long do electric car batteries last

Electric cars are becoming more and more popular in the international car fleet. More environmentally friendly than thermal models, they are...

Electric cars are becoming more and more popular in the international car fleet. More environmentally friendly than thermal models, they are increasingly affordable and are thus of interest to a new segment of the population. But how long do electric car batteries last ? Will it give up after only a few years as it does on a Smartphone? These are questions we are trying to answer.

The market is booming, and this is only the beginning. According to the BloombergNEFresearch institute, thermal cars have reached their peak in 2017 and will gradually give way to electric cars. By 2023, the market share of electric cars in the automotive industry is expected to be 7% worldwide. During this decade, we should also see a switchover with a drop in the price of this type of vehicle, which will eventually be at the same price as thermal cars.

Thus, the most massive electric cars could even be marketed at the same price as a thermal equivalent as early as 2022. Smaller vehicles and other markets will then gradually follow. BloombergNEF expects a market share of 10% in 2025, 28% in 2030, and 58% in 2040 in terms of registrations. In 2040, 31% of the cars still on the road would be fully electric.

So inevitably, many consumers are asking questions about electric cars, and in particular about the elements that differentiate them from conventional internal combustion cars: durability, performance, range, recharging, etc. One question often comes up: how long do electric car batteries last ? Will the battery give up quickly, forcing me to pay for an expensive replacement?

 In this dossier, we offer you some possible answers to help you see things more clearly.

How does an electric car battery work?

Before going any further, it's best to start with the basics with a few notions about how electric car batteries work. First of all, you should know that the technology used for electric car batteries is lithium-ion (Li-ion). You probably already have some knowledge about it since it has been used in our batteries for phones, laptops and many other electronic devices for many years now.

Tesla Model S Battery

Lithium-ion batteries have established themselves in all wireless devices in our daily lives thanks to their much higher charge density than previously used solutions such as Nickel Cadmium (NiCd) or Nickel Metal Hydride (NiMH), other types of rechargeable batteries. This means that much more energy can be stored in a battery of the same size. That's why lithium-ion first revolutionized small mobile devices such as phones or laptops.

As far as electric cars are concerned, in recent years, notably under the impetus of Tesla, manufacturers have managed to drastically reduce the price of lithium-ion batteries while boosting their performance. The technology is becoming increasingly mature, and electric cars are becoming more and more popular as they become more attractive to consumers in terms of both performance and price.

How do you measure the life of an electric car battery?

On an electric car, the degradation of parts and components is measured differently depending on their identity. For some, it is interesting to know their age, for example. This is not really the case for lithium-ion batteries since they do not deteriorate when they are not used. One factor that is often interesting is the mileage because it allows you to know how much the vehicle has been used. But mileage alone is not a very accurate indicator, as it does not reflect driving conditions. Driving mainly in the city on a daily basis or swallowing highway mileage once a month for the same mileage does not have the same impact on the car and its components.

In order to know how long do electric car batteries last fairly precisely, we, therefore, talk about the charging cycle, as with other devices that use lithium-ion technology. Note that a charge cycle does not correspond to recharging the vehicle (from the moment the car is connected to a power source to the moment it is disconnected) but to the battery going from 0 to 100%. If you charge your car from 30 to 80% for example, this only counts as half a charge cycle.

How long do electric car batteries last?

To determine how long do electric car batteries last, you have to take into account not only the number of charge cycles it can withstand but also the capacity of the battery. And finally, this is where it gets complicated, incorporating user-specific factors (such as the average number of miles traveled per year) if you want to achieve a lifetime in terms of age rather than mileage or charge cycle, which is what users generally look for.

Electric car battery pack on white

As mentioned earlier, the first important piece of information is the number of charge cycles the battery can hold. This number varies from model to model, so it's up to you to check with the manufacturer. Here we come up against a lack of recoil: electric cars are recent and it is difficult to estimate the number of charge cycles correctly. Of course, there is some initial feedback, but this necessarily comes from older models. And as the technology is evolving rapidly, taking the results of electric cars bought 10 years ago makes little sense, as batteries are much better optimized today.

Manufacturers generally aim for between 1,000 and 2,000 recharging cycles, with the norm being in the middle with 1,500 charging cycles. This is the most accurate indicator for measuring the life of a battery, but it is also the least concrete for a potential buyer, who often has no idea what such a figure might represent.

Battery capacity, measured in kWh, also influences battery endurance. The larger the capacity, the fewer charging cycles are needed, and therefore the longer the battery lives. But a larger battery also often means a heavier or more powerful car that consumes more energy. So you have to take into account not only the capacity of the battery but also the average consumption of the vehicle you're interested in. Your driving style also has an impact. If you're used to driving fast and using resource-intensive features, then expect to have to recharge more often and therefore enjoy a shorter battery life. And of course, distance traveled must also be factored into the equation. Normally, it's fairly easy for you to estimate the miles you drive each year if you already own a vehicle. It's up to you to take all these parameters into account to try to calculate approximately how long do electric car batteries last on a specific model and according to your usage.

Finally, the best way to get an idea of the battery life of an electric car is to check the manufacturer's warranties. Tesla, for example, offers a warranty on the battery of its Model S and Model X cars for up to eight years or 240,000 miles. So you're pretty sure you're safe for at least eight years or 240,000 miles, but you can certainly get much better, as the manufacturer is voluntarily setting the bar very low so that you don't have to do free repairs and replacements.

In June 2020, Tesla published a report on the ecological impact of its vehicles, and the data presented by the manufacturer is extremely promising with regard to battery life. For the Model S and Model X, battery capacity would decrease by an average of only 5% after 100,000 miles. And the loss would be even slower afterward, since it is only after 320,000 miles that the battery loses 10% of its initial capacity. So there's more to come: on average, a Tesla battery can last more than 10 years even when driving 30,000 miles per year.

Unfortunately, such studies are still very rare today, and the figures inevitably vary depending on the model. Tesla is the industry leader and its Model S and Model X are top-of-the-range products, so you wouldn't expect such performance from entry-level manufacturers not as advanced in electric vehicles. It is, therefore, necessary, in order to know how long do electric car batteries last, to look at each case individually.

When should you replace the battery in your electric car?

This is more a question of battery capacity than mileage or years. As explained earlier, each charging cycle reduces the amount of energy that the battery can store. As the car's range decreases, you'll be able to drive less distance on a full charge.

Of course, it's out of the question to wait for a very low ratio before changing the battery. If the capacity becomes really too low, the comfort of use will be non-existent because the user will be forced to limit himself to short distances before each recharge. It is therefore a question of feeling, but to give you an idea, it is not recommended to keep a battery that has fallen below the 70% threshold.

It is interesting to take a look at the manufacturer's warranties on this subject. At Tesla, the customer has the right to demand a battery replacement if the battery drops below 70% before eight years or X number of miles traveled (between 160,000 and 240,000 miles depending on the model). For ZOE, one of Europe's best-selling electric cars, Renault offers a guarantee if the battery falls to 66% of its initial capacity before eight years or 160,000 miles traveled. This rate rises to 75% if you have decided to lease the battery rather than buy it, an option offered by the French manufacturer to its customers. Another popular electric model, the Nissan LEAF is also covered if the battery degrades by a certain level before eight years or 160,000 miles traveled. The warranty is triggered if the capacity falls below 9 bars out of 12 (75% equivalent).

If you're worried that the battery in your electric car will soon run out, turn to a manufacturer that offers an attractive guarantee. Not all manufacturers take this trouble, so check your rights before you buy them. This will give you peace of mind for a long period of time unless you swallow the miles at high speed.

How to increase the life of an electric car battery?

As we have seen, electric car batteries are not really a problem today. But if you want to keep your vehicle for a very long time without changing it, or if you own an old model that does not benefit from the latest technology, you can adopt behaviors that allow you to extend the life of your electric car battery.

Of course, taking into account what we were saying earlier about the impact of charging cycles on the battery, anything that reduces the energy consumption of the vehicle will increase its lifespan, since there is less need to recharge the car. In order to do this, it is recommended to drive at a measured speed in accordance with the principles of eco-driving (no sudden acceleration and braking, for example), which also apply to cars with combustion engines.

Be careful not to overuse battery-powered features that are of little use to you, such as air conditioning, integrated screens if any, the audio system... Of course, these are not the most resource-intensive equipment, so don't hesitate to use them when you really need them, it's not a question of depriving yourself of everything. But turning them off when you're not using them anymore or moderating your consumption a little can help to gain in longevity in the long run.

Take care to drive with properly inflated tires. If this is not the case, in addition to the danger and the loss of comfort that this implies, other elements of the car will have to compensate for the weakness of the tires, thus consuming energy. We advise you to avoid using conventional power sockets to recharge the vehicle, as these can damage the battery in the long term. Instead, use charging stations or install a specially designed charging device at home. Fast chargers can also damage the battery.

Temperature also plays a role. Try to protect your car from cold and heat as much as possible. Their lifespan may be shortened if you live in an area with extreme temperatures.

One advice that often comes up is, as on other devices carrying a lithium-ion battery, not to wait until the last moment before recharging the battery and to prefer regular short recharges rather than big charging sessions to reach 100%. While it is easy to implement on Smartphones with our compact chargers that can be carried everywhere, the situation is quite different with electric cars. Many users charge at night for convenience. You should know that it's not a big deal and you don't risk ruining your battery that way. The intelligent systems of electric cars themselves take this into account in order to avoid altering the capacity of the batteries, just as they do on mobile phones for that matter. You can therefore leave your vehicle plugged in and recharge it until it reaches maximum capacity, the transfer of energy will be interrupted automatically as soon as necessary. On the Tesla Model S P100D for example, it is thus impossible to fill the 102.4 kWh capacity of the battery, the maximum is 98.4 kWh. So there is a basic capacity of 4 kWh that is not used.

Electric car batteries expected evolution

Technologies related to electric car batteries are constantly improving. Today, lithium-ion has become the standard used by all manufacturers, replacing the lead-acid previously used. In the short to medium term, lithium-ion is unlikely to be dethroned. While lithium-ion is reaching its limits on mobile devices, for example, this is not yet the case in the electric vehicle market.

Heavy investments are being made to make the best use of lithium and to improve the performance of batteries, both in terms of range and lifetime. Several avenues seem extremely promising for the sake a higher autonomy, and consequently a less frequent need for recharging and thus a longer life span.

We are not there yet, but the promises for the future of electric car batteries are impressive. Tesla claims to be able to eventually offer batteries capable of lasting more than one million miles and capable of withstanding up to 4,000 recharge cycles, more than double that of today. Contemporary Amperex Technology Limited (CATL), a Chinese company specializing in the production of lithium-ion batteries for electric vehicles, is looking even further ahead and announces a battery with a life of two million miles and 16 years. Lithium-ion still seems to have a bright future ahead of it.

But the post-lithium-ion process is already underway, although it is not yet clear what technology will be used and when. One speaks for example about the batteries lithium-air (or lithium-oxygen), which have the characteristic to exploit the ambient oxygen to function. Since some of the components are not directly integrated into the battery, the battery becomes lighter and takes up less space. Still, with the aim of benefiting from a higher energy density, fluoride batteries (an ionic form of fluorine) with liquid electrolytes are also being developed.

Then we have a growing interest in solid electrolyte batteries, also known as "all-solid battery" or simply "solid battery". They are distinguished by their electrolyte: a plate of glass or gel, in solid form. It is a system that is already used for pacemakers. The benefits are multiple. These batteries are much safer and less sensitive to extreme temperatures than lithium-ion solutions. They also require fewer precautions in use. Solid-state batteries are also cheaper to produce, in particular, they do not require precious materials. All this results in a much more attractive energy density, up to three times higher than that of current batteries. Toyota and Volkswagen have already announced that they want to market electric cars with solid-state batteries as early as 2025. All the major groups are on the move: Ford, BMW, Hyundai, General Motors, Honda... Siemens has also been working with suppliers for several years now.

Finally, you may have heard about sodium-ion batteries. They have the advantage of being very durable (4,000 charge cycles), extremely quick to charge, and inexpensive to produce. But their low electrical energy density makes them an unlikely candidate for the future of the automotive industry. This technology is more promising for less resource-intensive devices, such as scooters or electric bicycles.

Conclusion

There is no indisputable truth about how long do electric car batteries last. This depends on the vehicle model, driving style, and external parameters that are difficult to control, such as the ambient temperature. Battery degradation is a fear of many consumers, but the latest findings give cause for optimism about the durability of batteries, especially the latest generations, which benefit from advanced technologies.

If you're not in a hurry to buy an electric car, keep in mind that manufacturers keep improving year after year with batteries that should last longer and cars that have a longer range. We will also have more hindsight in this market, with more accurate data on battery life expectancy.

In the meantime, if you want to switch to electric power, prefer a model that comes with a battery replacement guarantee for X years or X miles. If you are interested in a model that you intend to keep longer than the warranty period, ask about how long do electric car batteries last and the replacement price.