For example: Does fast charging damage the battery? Are there charging stations on highways? Can new energy vehicle batteries be recycled? Read on to find out the answers!
What damage does fast charging cause to the battery?
Everyone has heard that electric vehicles have fast charging and slow charging, and everyone knows that fast charging is much faster than slow charging, but what is the essential difference between them?
The concepts of fast charging and slow charging: Fast charging and slow charging are relative concepts. Generally, fast charging is high-power DC charging, which can charge the battery to 80% capacity in half an hour. Slow charging refers to AC charging, which takes 6-8 hours to charge.
The voltage for fast charging (DC charging) is generally higher than the battery voltage. For example, the battery voltage of the BYD Qin is 400V DC, so the DC charging voltage should be above 500V. The Qin has a capacity of 13kWh, so its charging current should be able to reach 32.5A, meaning the fast charging power is P=UI=500V*32.5A=16.25KW.
Slow charging involves plugging the battery into a standard 220V AC outlet in the home. Since batteries cannot accept AC charging, slow charging converts the 220V AC power to DC power and then boosts it to the battery's charging voltage, such as 500V DC power, before using this 500V DC power to charge the battery.
Therefore, we can conclude that the maximum charging power of slow charging is approximately P=UI=220V*10A=2.2KW. It is clear that the power of fast charging (16.25KW) is far greater than that of slow charging (2.2KW), thus demonstrating that fast charging is significantly faster than slow charging.
Advantages and disadvantages of slow charging: lower current, longer charging time, lower charger and installation costs; can take full advantage of off-peak electricity hours for charging, reducing charging costs; can deeply charge the battery, improve battery charging and discharging efficiency, and extend battery life.
Household slow charging AC: Since the standard 220V AC sockets in a typical household are 10A and 16A, for safety reasons, the charging current for slow charging is generally less than 10A, calculated according to the 10A standard.
Advantages and disadvantages of fast charging: It can quickly replenish the battery pack in a short period of time, and the charging speed is fast; however, the installation requirements and costs of charging equipment are relatively high, the current and voltage are relatively high, the impact on the battery is greater in a short period of time, and long-term fast charging will affect the battery life.
The dangers of fast charging: Fast charging of lithium batteries comes at the cost of sacrificing the battery's cycle life. This is because batteries are devices that generate electrical energy through electrochemical reactions, and charging involves a reverse chemical reaction. Fast charging will input a large current into the battery in an instant. Frequent use of fast charging mode will reduce the battery's recovery ability and reduce the number of charge-discharge cycles.
Simply put, fast charging places high demands on battery quality, and the reaction conditions under high current are too harsh and intense, deviating far from equilibrium, which significantly reduces battery life and safety. Therefore, it should be avoided as much as possible when unnecessary. Slow charging, on the other hand, can effectively avoid these problems.
How to properly cycle fast and slow charging?
During normal driving, if the battery indicator lights up red and yellow, the battery should be charged. If only the red light remains on, stop driving and charge the battery as soon as possible; otherwise, over-discharging the battery will severely shorten its lifespan. Charge the battery after a short period of use after a full charge, and avoid prolonged charging, as this can lead to overcharging and overheating. Overcharging, over-discharging, and undercharging all shorten battery life.
There are also charging stations on highways.
According to the plan, by 2020, the State Grid Corporation of China will have built a total of 10,000 public fast charging stations and 120,000 charging piles nationwide, fully covering the expressway fast charging network in all cities in the Beijing-Tianjin-Hebei region, the Yangtze River Delta region, and other major cities in other regions, covering a total of 202 cities and 36,000 kilometers of expressways. By 2017, a public urban charging network with a radius of five kilometers had been basically completed in the Beijing area.
Highway-specific charging card: State Grid charging stations on highways require a "highway-specific charging card"; regular city charging cards are not accepted. With this card, you can generally charge your vehicle anytime, anywhere. How to apply: Vehicle owners can apply for a "highway-specific charging card" at designated service centers.
If you don't have time to go to the service center in person, you can call the 95598 customer service hotline at least 45 minutes in advance and up to 3 days in advance to reserve a charging service area. The staff of the highway charging station will arrive within 45 minutes to guide the car owner on charging.
Can battery swapping be implemented for new energy vehicles?
Currently, there is no unified standard for battery swapping in the electric vehicle industry, and there are generally some differences in opinions regarding this initiative. Specifically:
1. Battery model issue: There are many electric vehicle brands on the market, and the battery models and manufacturers of each model are different, so electric vehicles from different brands are not interchangeable.
From a developmental perspective, the future demand for battery swapping will extend beyond taxis to include private electric vehicles. To enable private cars to enjoy battery swapping services, issues such as battery specifications and charging standards must be addressed. Efforts should be accelerated to standardize battery specifications and charging standards, laying the foundation for future battery swapping services for private cars.
2. Battery reserve issue: Each gas station within the Third Ring Road in Beijing serves an average of 300 cars per day. If a battery swapping station serves 200 electric vehicles per day, then a single charging and swapping station needs at least 100-150 batteries in reserve.
Different brands of vehicles use different battery materials. For example, the EV200 uses ternary lithium batteries from SK Corporation of South Korea, while the BYD E6 uses ET-POWER iron batteries developed and produced independently. They are not interchangeable, and each type of battery needs to be stocked.
3. Standardization Issues: The construction of battery swapping stations has accelerated the popularization of electric vehicles nationwide, and it is not surprising that electric vehicles are used across cities. However, the battery swapping methods of different brands of electric vehicles are not exactly the same, and automatic battery swapping systems may not be universal.
While constructing battery swapping stations, unified battery swapping methods and standards should be established to enable cross-regional battery swapping. Electric vehicles are rapidly becoming more common in cities, and with the construction of battery swapping stations, electric taxis may replace gasoline-powered taxis. However, to achieve widespread adoption of electric vehicles, the government should accelerate the standardization of electric vehicle battery specifications, charging standards, and battery swapping standards, laying the foundation for the future widespread adoption and cross-regional use of private electric vehicles.
Can new energy vehicle batteries be recycled?
my country's research on power batteries has primarily focused on improving their safety performance and lifespan, with relatively little attention paid to recycling. With the explosive growth of new energy vehicles, it is essential to establish a comprehensive power battery recycling system by drawing on international experience.
The United States has conducted comprehensive research on power batteries and has now established a well-developed commercial operation model. The collaboration between General Motors and ABB has yielded significant results, feeding electricity collected from Chevrolet Volt battery packs back into the grid to ultimately power residential and commercial homes. After trials, the reorganized modular unit can support two hours of power for 3-5 American households. In the near future, similar applications will be able to provide backup power for some homes and small commercial buildings during power outages. Simultaneously, storing energy during periods of discounted electricity pricing for use during peak hours can also fill gaps in wind, solar, or other renewable energy generation.
In Germany, battery manufacturers and importers must register with the government, distributors must organize a recycling mechanism, and users are obligated to hand over used batteries to designated recycling organizations.
The implementation of this extended producer responsibility system has led to the establishment of a comprehensive battery recycling system. Simultaneously, the German Federal Ministry for the Environment has funded two demonstration projects for the recycling and utilization of power batteries, researching the resource utilization of spent power batteries.
A popular approach in Japan is to use discarded lithium batteries to build solar power systems. When there is plenty of sunshine, the solar panels generate electricity and supply it to the energy storage system, which then powers household appliances. On cloudy days or at night, users can purchase electricity from the power company during periods of low electricity prices to charge the energy storage system, while during periods of high electricity prices, they can simply draw power from the energy storage system.
Is buying a used electric car a reliable investment?
Currently, the used new energy vehicle market in major first-tier cities is almost a blank slate, with neither prices nor market demand. However, as the number of electric vehicles increases, relevant government departments and manufacturers will proactively address issues such as resale value and battery recycling. Nevertheless, it's undeniable that new energy vehicles, whether through car-sharing or private purchase, are increasingly becoming a part of our lives. Those working in the used car market point out that they are unwilling to buy used new energy vehicles because the market doesn't yet recognize their value, buyer demand is too low, and they are difficult to sell.
Current situation of the used electric vehicle market
The current state of the used new energy vehicle market: First, dealers are unwilling to buy them, and prices fluctuate wildly, with discounts ranging from tens of thousands to hundreds of thousands of yuan. There is no strict standard for determining the purchase price. Second, after-sales issues are complex. Maintenance and repairs are very limited, requiring advance booking at 4S dealerships, which is practically inconvenient for consumers living far from their local area. Third, driving range is a concern. After all, new energy vehicles are driven by electric motors, not engines. Battery lifespan and driving range are critical factors, and the performance of used vehicles acquired through purchase is difficult to guarantee in this regard.
