Electric vehicles refer to vehicles that are powered by on-board power supply and driven by motors to drive the wheels, and meet the requirements of road traffic and safety regulations. Its working principle is to rely on the battery to generate current, through the power regulator to reach the motor, drive the power transmission system, drive the car to drive.
New energy vehicles mainly rely on charging piles as energy supply devices. From the perspective of charging type, charging piles can be divided into DC charging piles and AC charging piles, and the corresponding output is DC and AC.
DC charging, also known as fast charging, is a charging method that makes the battery power grow rapidly in a short period of time. The power of the DC charging pile is generally between 15KW-120KW, every 15KW is a gear, when the DC charging pile starts, the built-in conversion module of the charging pile is directly used to convert the alternating current of the power grid into direct current, and charge the battery through the charging port of the electric vehicle. The charging current of the DC charging pile is large, ten times or even dozens of times the conventional charging current, the charging speed is very fast, generally in 30 minutes can be filled with 80% of the power for the electric vehicle, after that, from constant current charging to constant voltage charging, in order to protect the battery, and charge the power to a fuller.
The advantages of this method are that the charging power is large, the charging speed is fast, and it can be fully charged in about 1 hour, which is suitable for situations where the power needs to be replenished quickly in a short time. But the defects of this method are also more obvious, on the one hand, because its power is quite large, directly charging our vehicle will cause a considerable impact on the lines in our cars, and long-term use will damage the lines in our cars. On the other hand, in addition to the high cost, DC fast charging also has relatively high requirements for batteries. Because the conductive materials used inside the battery can not completely guide away this high-power current, the remaining current will cause an impact on the inside of the battery, which is easy to increase the temperature of the battery in a short period of time, and make the lithium ions inside the battery fall off, making the battery voltage unstable, which will cause damage to the battery and reduce the life of the battery.
AC charging, the so-called slow charging, is a charging method that uses charging piles to convert the alternating current of the power grid into direct current through the charging port and through the on-board charger and charge the battery. Its power is smaller, generally below 7KW. The disadvantage of AC charging is that the charging event is long, and the charging time of different brands is not the same, and it generally takes 6-8 hours to be fully charged. Because AC charging uses constant AC power to charge, the voltage is stable and will not cause impact on the lines of our vehicles and the battery of the vehicles, and the requirements for current are not as high as DC charging piles, and the cost is relatively cheap, so in the case of sufficient time, it is better to choose conventional AC slow charging as much as possible.