Wen/Tao Li

As the power source of electric vehicles, batteries have a very important impact on the use of electric vehicles. However, the power of batteries is not endless, and they need to be supplemented after consumption. The charging system provides energy supply for the operation of electric vehicles. It is an important basic support system for electric vehicles and an important link in the process of commercialization and industrialization of electric vehicles. New energy vehicle charging pile With the rapid development of electric vehicle industry, charging technology has become one of the key factors restricting the development of the industry. Intelligent and fast charging mode has become the trend of electric vehicle charging technology development.

Do you know various charging methods of electric vehicles? Perhaps you have heard of DC charging and AC charging, as well as fast charging and slow charging, but do you know what they mean? Today, we will talk about these common problems in battery charging through the topic of electric vehicle batteries, so that we can have a deeper understanding of electric vehicles.

Let's briefly talk about what is DC and AC first. Direct current is called DC for short, also known as "constant current". Constant current is a kind of direct current, which is constant in size and direction. It was discovered by Edison. AC, for short, refers to the current whose current direction changes periodically with time. The average current in a cycle is zero. Unlike DC, the direction of electric vehicle charging pile will change with time, while DC has no periodic change.

After talking about the two current forms, let's look at what is DC charging and what is AC charging. At present, electric vehicles are charged mainly through charging piles. According to the charging mode, charging piles can be divided into AC charging piles, DC charging piles, and AC/DC integrated charging piles. AC charging has low power, requires a long charging time, but consumes less battery. On the contrary, DC charging piles have high charging power and fast charging, But the loss of battery is also large.

In addition, we need to be clear that the battery has a positive and negative pole, so the power battery must be charged with DC, and only DC. So the national power grid is all AC power. How can we turn AC power into DC power? In short, the rectifier is used. The main reason why it is divided into DC charging pile and AC charging pile is that the position of the rectifier is different.

First of all, our car has its own rectifier. The AC charging post only outputs a 220V power supply to the charger during the charging process. The power of the charging post cannot exceed the power of the motor in the car. Then, the on-board charging device converts the AC power in the grid into DC power to charge the battery. However, due to the small space in the car, the on-board charging device cannot be too large, and the cooling system is difficult to do, so the charging method through the AC pile is relatively slow, so it is generally installed in the parking lot of the community.

The DC charging pile is different. The DC charging pile is equipped with a rectifier, which directly converts the output current into DC current to charge the battery. Because there is no space limit, the power of the rectifier can naturally be greater, and the charging efficiency is naturally higher, so it is generally installed in the charging station near the highway. New energy vehicle maintenance At present, most electric vehicles can charge 80% of the electricity in 30 minutes when using DC charging.

According to the speed of the above two charging methods, we further divide them into fast charging and slow charging, corresponding to DC charging and AC charging respectively. I believe that we have a clearer understanding of the DC charging pile and the AC charging pile, fast charging and slow charging. The main choice of the two is the difference in efficiency and battery life. The AC charging pile can be used when the car is not used at night, and the DC charging pile is certainly chosen when the car is in urgent need of charging.

Summary:

At present, the battery charging methods are far more than these, including wireless charging, vehicle charging bank, etc. All are under development. If electric vehicles want to make great progress, it is inevitable to solve the charging problem, and it is expected that the future charging technology will have greater breakthroughs.