7-hole charging piles and 9-hole charging piles are two common types of electric vehicle charging interfaces, and they differ significantly in design, function, and usage scenarios. The following is a detailed analysis of the differences between these two types of charging piles.
Charging Interface Design Differences
7-hole charging piles, also known as AC charging piles, are usually equipped with 7 contact holes, including 5 large holes and 2 small holes. This design is designed to fit most standard AC electric vehicle charging ports. The charging process of an AC charging post requires an on-board charger (OBC) inside the vehicle to convert AC power to DC power and then charge the battery. This type of charging is widely recognized as "slow charging" because of its relatively slow charging speed, which typically ranges from 3kW to 22kW.
In contrast, a 9-hole charging post, also known as a DC charging post, is equipped with nine contact holes, including two large holes, one medium hole and six small holes. This design is designed to accommodate higher power DC charging needs. DC charging piles are able to provide DC power directly to the battery of an electric vehicle, bypassing the on-board charger, thus allowing for fast charging, usually with powers of 50kW or more, and even up to hundreds of kilowatts.
Charging speed and efficiency
Since 7-hole charging piles require an on-board charger for power conversion, their charging efficiency is limited by the power of the on-board charger. Most AC chargers have a power of between 3kW and 22kW and take a long time to charge, usually several hours to fully charge an electric vehicle. This type of charging is suitable for family night charging or charging during working hours in scenarios that do not require quick replenishment of power.
The 9-hole charging post, on the other hand, can realize fast charging with much shorter charging time due to its high power output. For example, some high power DC charging piles can charge an EV to 80% in 30 minutes. This type of charging is suitable for scenarios that require quick replenishment of power, such as highway service areas or commercial charging stations.
Installation and Usage Scenarios
7-hole AC charging piles are usually small in size and flexible in installation, suitable for parking spaces in homes and offices. Due to its low power and low grid requirements, it is more common in older neighborhoods or small commercial locations with limited power distribution capacity.
9-hole DC charging piles, on the other hand, are usually larger, requiring more installation space and higher distribution capacity. Therefore, they are more suitable for installation at public charging stations, commercial areas or along highways to serve electric vehicles that require fast charging.
Safety and Compatibility
Both 7-hole and 9-hole charging posts are designed with an anti-dulling mechanism to ensure that users do not mistakenly insert the charging plug into an incompatible charging socket. In addition, all charging ports are required to pass a mandatory vehicle crush test to ensure that their mechanical and insulating properties do not change under extreme conditions.
Summarization
The 7-hole AC charging post and the 9-hole DC charging post have their own characteristics in terms of design, function and usage scenarios. AC charging piles are suitable for home and office use with their flexible installation and low grid requirements, while DC charging piles are more suitable for public charging stations and scenarios requiring fast charging with their high power and fast charging advantages. As the electric vehicle market continues to develop, both types of charging piles will play an important role in promoting the popularization of new energy vehicles and supporting sustainable development.