Advantages and Disadvantages of DC Fast Charging and AC Slow Charging of Charging Piles

Charging pile is a charging device that provides DC/AC power for new energy electric vehicles. The charging pile functions like a refueling machine in a gas station. Its input is connected to the AC power grid, and its output is charged by a charging plug for the battery of an electric car. Charging piles are installed in public buildings (public buildings, shopping malls, public parking lots, etc.) and residential parking lots, and can be fixed on the ground or walls.

AC pile

AC pile charge the power battery through the vehicle charger, with small power, slow charging and low cost, commonly known as "slow charging". The AC charging pile connects the charging socket to the on-board charger to charge the power battery.

AC charging pile input voltage is 220V, charging power is generally 7KW, it takes 8-15 hours to fully charge, mainly used for private charging pile in residential areas. The manufacturing and installation cost of AC charging pile is only 800-1200 yuan/pile (excluding line transformation and expansion), with simple structure and small volume, it can be hung on the wall, and portable can be carried directly with the car.

DC pile

DC pile directly charge the power battery, with large power, fast charging and high cost, commonly known as "fast charging". The DC charging pile converts alternating current to direct current, charging the ev battery directly through the charging socket.

The input voltage of DC charging pile is 380V, and the power is usually above 60KW. It only takes 20-150 minutes to fully charge. DC charging piles are suitable for scenarios requiring high charging time, such as operating vehicle charging stations for taxis, buses and logistics vehicles, as well as public charging piles for passenger vehicles.

Disadvantages of DC pile are:

1) The cost is much higher than ac pile. Dc piles require large-volume transformers and AC-DC conversion modules. The manufacturing and installation cost of charging piles is about 0.8 yuan/W, and the total price of 60kW DC piles is about 50,000 yuan (excluding civil construction and capacity expansion). In addition, large-scale DC charging stations have a certain impact on the power grid, and high-current protection technologies and methods are more complex, resulting in higher costs for transformation, installation and operation.

2) May cause damage to the power battery. The output current of dc pile is large, and more heat will be released when charging. High temperature will lead to sudden reduction of power battery capacity and damage of cell after long use.