What are DC and AC EV Charger？

yangh

What is the difference between them?

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The essential difference between them is that a DC charger is a charging equipment, which converts the AC power from the AC grid into DC power within a certain voltage range, such as 250V-1000V, and matches it with the battery of an electric vehicle.
However, an AC charger is not a charging equipment, its main function is switching and control. It requires an on-board charger(OBC) to realize the charging function.

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Obviously, it is not suitable to make the power of AC charger large, it would too heavy for the vehicle.
The maximum power of a single-phase AC charger is 7kW, and 22kW for three phase AC charger. Both of their rated power current is 32A.

DC charging piles mainly include integrated charging piles and split charging piles. The charging module and charging gun of the integral charging pile are on the same cabinet, and the charging module and charging gun of the split charging pile are separate.
They all have several charging modules. The integral charging pile is generally equipped with one or two charging guns, and the split type can be equipped with many charging guns. When the EV car is charging, the charging gun will dispatch several charging modules to charge the car according to the needs of the car and the status of the charging pile.
For charging stations, I recommend using split charging piles because it can better dispatch energy and charging modules.

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Let us introduce the definition of the Chinese standard charging port, the definition of each terminal is shown in the figure.

For DC charger, "S+" and "S-" are used for communication between the charger and the battery, "CC1" and "CC2" are used to confirm the connection between the charger and the battery, "DC+" and "DC-" are the positive and negative poles of the main charging circuit, "A+" and "A-" are used for the auxiliary power (12V battery) charging, PE is the protective earthing conductor.

For AC charger, "CC" and "CP" are used for communication between the charger and the battery (OBC), "L1" , "L2", "L3", "N", are the positive and negative poles of the main charging circuit, PE is the protective earthing conductor.

It is worth noting that the"L2" and "L3" terminals of the single-phase charging pile and the single-phase OBC are usually made of plastic. Most cars on the market are equipped with single-phase OBC. Whether it is the limitation of the communication protocol or the main circuit,, connecting a single-phase OBC to a three-phase charging pile will not increase the charging power of the car.

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The last question is how to choose a charging pile. I think the usage scenario is the most important.
For destinations, such as home or work, we need to stay for a long time. I recommend choosing an AC charging pile. And Slow charging is more friendly to the health of the battery.
For non-destination, such as the service area of the highway, it is obvious that a high-power DC charging pile should be selected, because no one wants to wait too long for charging during the journey.