Is the life of an electric car really only 6-8 years?
This is a question that many people are concerned about, especially for those who want to buy or already own an electric vehicle. As a new energy vehicle, electric vehicles have the advantages of lower carbon emissions, higher energy efficiency, and less maintenance costs than traditional fuel vehicles, but they also have challenges in terms of battery life, mileage, and charging facilities. So, what is the life of an electric car? When the life expectancy is reached, can the electric car still be driven? This article will answer these questions for you from the following aspects.
1. Definition of the life of an electric vehicle
First of all, we want to make it clear that the life of an electric vehicle does not refer to the time from production to scrapping of an electric vehicle, but the time that an electric vehicle can be used under the premise of maintaining normal performance and safety. In other words, EV life is not equal to battery life, but is determined by both battery life and other component life. Therefore, we cannot simply summarize the life of an electric vehicle with a single number, but judge it according to different criteria and conditions.
2. Factors affecting the life of electric vehicles
There are many factors that affect the life of an electric vehicle, the main one of which is the battery. At present, the mainstream electric vehicles on the market use lithium-ion batteries, which have the advantages of high energy density, low self-discharge rate, and long cycle life, but also have disadvantages such as capacity attenuation, power attenuation, and safety reduction. Generally speaking, when the capacity of lithium-ion batteries is attenuated below 80%, it is not suitable for car use, because this will affect the range and power performance. The capacity attenuation of lithium-ion batteries is affected by the following factors:
- Number of charge and discharge: The more times of charge and discharge, the faster the capacity decays. In general, lithium-ion batteries can withstand about 1,000 charge-discharge cycles, after which the capacity drops to about 80%.
- Charge-discharge depth: The larger the charge-discharge depth, the faster the capacity decays. Charge-discharge depth refers to the percentage of capacity occupied by each charge-discharge. For example, if you only put it to 50% after each charge, then the depth of charge and discharge is 50%. Generally speaking, when the depth of charge and discharge is between 20%~80%, the impact on capacity attenuation is minimal.
- Charge-discharge rate: The faster the charge-discharge rate, the faster the capacity decays. The charge-discharge rate refers to the percentage of capacity occupied by charging and discharging per hour. For example, if it is fully charged or discharged 100% within an hour, then the charge-discharge rate is 1C. Generally speaking, when the charge-discharge rate is between 0.5C~1C, it has the least impact on the capacity attenuation.
- Temperature: The higher or lower the temperature, the faster the capacity decays. Temperature has an effect on both the chemistry and physical structure of lithium-ion batteries. In general, lithium-ion batteries perform best at around 25°C and worst at 0°C or above 45°C.
In addition to the battery, there are some other factors that can also affect the life of an electric vehicle, such as:
- Driving habits: The worse the driving habits, the shorter the life of the electric vehicle. Driving habits include acceleration, braking, steering, changing lanes, and more. If you often accelerate sharply, brake sharply, make sharp turns, change lanes frequently, etc., it will increase the energy consumption and mechanical wear of the electric vehicle, thereby shortening the life of the electric vehicle.
- Road conditions: The worse the road conditions, the shorter the life of the electric vehicle. Road conditions include pavement smoothness, slope, congestion, etc. If you often drive on bumpy, steep, and congested roads, it will increase the energy consumption and mechanical wear and tear of the electric vehicle, thereby shortening the life of the electric vehicle.
- Maintenance: The better the maintenance, the longer the life of the electric vehicle. Maintenance includes regular inspections, cleaning, replacement, repairs, etc. If the electric vehicle is maintained in time, it can find and solve the problem in time to avoid the occurrence or deterioration of the failure, thereby prolonging the life of the electric vehicle.
3. Estimation of the life of electric vehicles
Based on the above influencing factors, we can make a rough estimate of the life of an electric vehicle. Here we take a more common electric vehicle on the market as an example, its parameters are as follows:
- Battery capacity: 60 kWh
- Cruising range: 400km
- Number of charge and discharge: 1000 times
- Charge/Discharge Depth: 80%
- Charge and discharge rate: 0.5C
- Temperature: 25°C
Assuming that this electric car travels 100km per day, then it needs to be charged and discharged once a day, and it needs to be charged and discharged 365 times a year. Well, without considering other factors, the lifespan of this electric car is about 1000/365=2.74 years. In other words, after 2.74 years, the battery capacity of this electric car will be attenuated to less than 80%, and the range will be reduced to less than 320km.
Of course, this is just an idealized situation, and there are actually other factors to consider. For example, if the temperature increases or decreases by 10°C, the capacity decay rate will increase by 10%~20%; if the depth of charge and discharge increases or decreases by 10%, then the capacity decay rate will increase or decrease by 5%~10%; if the charge and discharge rate increases or decreases by 0.1C, the capacity decay rate will increase or decrease by 5%~10%; if driving habits, road conditions, maintenance and other factors change, then the capacity decay rate will also change. Considering these factors, we can get a more reasonable estimate:
- Best case: temperature 25°C, charge-discharge depth 20%, charge-discharge rate 0.5C, good driving habits, good road conditions, good maintenance. At this time, the capacity decay rate is the lowest, about 3%~5% per year. Then, after 6~8 years, the battery capacity of this electric vehicle will be attenuated to less than 80%, and the cruising range will be reduced to less than 320km.
- Worst-case scenario: temperature 45°C or 0°C, charge and discharge depth 80%, charge and discharge rate 1C, poor driving habits, poor road conditions, poor maintenance. At this time, the capacity decay rate is the highest, about 10%~20% per year. Then, after 2~4 years, the battery capacity of this electric vehicle will be attenuated to less than 80%, and the cruising range will be reduced to less than 160km.
- Average situation: the temperature fluctuates around 25°C, the charging and discharging depth is 50%, the charging and discharging rate varies between 0.5C~1C, and the driving habits, road conditions, and maintenance are average. At this time, the capacity decay rate is between 5%~10% per year. Then, after 4~6 years, the battery capacity of this electric vehicle will be attenuated to less than 80%, and the cruising range will be reduced to less than 240km.
As can be seen from the above estimates, the range of EV life is large, ranging from 2 years to 8 years. This also illustrates the uncertainty and variability of the life of an electric vehicle, which depends on a combination of many factors. Therefore, we cannot generalize about what the life of an electric vehicle is, but judge it according to the specific situation.
Fourth, when the life expectancy is reached, can the electric car still be driven?
So, when the battery capacity of an electric vehicle is attenuated to less than 80%, can the electric car still be driven? The answer is: yes, but not recommended.
There are several reasons for this:
- Reduced range: When an EV's battery capacity decays below 80%, the range decreases accordingly. This means that you need to charge more often, or you can only drive short distances. This will bring inconvenience and distress to your travel, and will also increase your energy consumption and costs.
- Reduced power performance: When the battery capacity of an electric vehicle is attenuated below 80%, the power performance is also affected. This means that your ability to accelerate, climb, overtake, etc., will become worse. This will affect your driving experience and safety, and will also increase your driving risk and accident probability.
- Reduced safety: When an EV's battery capacity decays below 80%, safety also decreases. This is because lithium-ion batteries may experience dangerous situations such as aging, short circuit, overheating, fire, and explosion in the process of capacity decay. This can cause serious threats and losses to your person and property.
Therefore, when the battery capacity of an electric vehicle decays below 80%, we recommend that you replace it with a new battery or buy a new electric vehicle in time. This will ensure that your travel is convenient, comfortable and safe.
5. How to extend the life of electric vehicles?
Now that we know the factors and outcomes that affect the life of an electric vehicle, there are a few things we can do to extend the life of an electric vehicle. Specifically, we can start from the following aspects:
- Choose the appropriate charging and discharging method: Try to avoid excessive charging and discharging and rapid charging and discharging, and choose the charging and discharging method that suits your car needs. Generally speaking, it is recommended to charge and discharge when the remaining capacity of the battery is between 20%~80%, use a charge and discharge rate of 0.5C~1C, and do not wait until the battery is completely depleted or fully charged and then stop charging and discharging.
- Maintain a suitable temperature: Try to avoid using and storing electric vehicles at too high or too low temperatures, choose a place with shade, ventilation and moisture-proof to park electric vehicles, use charging equipment with temperature control function, and do not charge or discharge at high or low temperatures for a long time.
- Develop good driving habits: Try to avoid driving behaviors such as rapid acceleration, sudden braking, sharp turns, and frequent lane changes, choose a flat, spacious and smooth road surface, maintain a reasonable speed and distance, obey traffic rules and signals, and reduce unnecessary energy consumption and mechanical wear.
- Do a good job of maintenance: Regularly inspect, clean, replace, repair and other maintenance of electric vehicles, find and solve problems in time, avoid failures or deterioration, and prolong the service life of electric vehicle components. Especially for batteries, it is necessary to pay attention to waterproof, dustproof, shockproof, anti-corrosion and other measures to keep the battery in good condition.
In short, the life cycle of electric vehicles is a complex and important topic, which is related to the quality and safety of our travel. We should judge the life of electric vehicles according to our actual situation and take some effective methods to extend the life of electric vehicles. In this way, we can enjoy the convenience and fun brought by electric vehicles.