Xiaomi SU7 wire harness "copper to aluminum" behind, is the progress of ultrasonic aluminum wire welding process Apr 18, 2024

Recently, the topic of Xiaomi car SU7 wiring harness "copper to aluminum" has triggered heated discussion among netizens.

Why did Xiaomi choose aluminum conductor as the wiring harness material of SU7?



Xiaomi Blog:

Xiaomi Automobile official said, "Aluminum conductor in conductor performance, safety performance and copper conductor is the same, but the conductivity is different, and also has the advantages of lightweight."

"At present, most of the charging wiring harnesses of the Oems use aluminum conductor schemes, and so does Millet SU7."

In fact, in the field of wire harness processing, the application of aluminum wire and aluminum bar has become an important consensus in the industry.

Since aluminum conductors have the advantages of light weight and low price, why did they not have large-scale applications in the early days?


Why is Xiaomi SU7 wiring harness aluminum, not copper? Is it "cutting corners"?

At present, most of the charging wiring harnesses of the Oems use aluminum conductor schemes, and so does Millet SU7. Aluminum conductors are the same as copper conductors in conductor performance and safety performance, but the conductivity is different, but the same current-carrying capacity can be achieved through different cross-sectional areas.


But aluminum conductors also have advantages that copper conductors do not have, such as lightweight, aluminum wire can be 30% lighter than copper wire.

Therefore, for trams, because of the extra attention to battery life and fast charging, "copper to aluminum" is already the mainstream development trend of the industry, and cutting corners is absolutely nonsense.


Advantages of ultrasonic welding:

Short welding time and high quality

Short welding time

Good electronic properties

High mechanical strength, easy to operate

Low thermal stress

The device is easy to connect and flexible to use

Low operating cost, energy saving and environmental protection

Integrated process control


Technical difficulties of aluminum wire welding

The technical difficulties of ultrasonic aluminum wire welding are mainly as follows:

· The mechanical strength of aluminum wire is only one third of that of copper wire, which will affect the welding tension of the terminal.

· It is easy to form an oxide film on the surface of aluminum conductor, which has the property of insulation and affects the electrical conductivity.

· aluminum wire is easy to stick to the welding head and fixture, affecting the continuity of production;


In addition, because the resistivity of aluminum is greater than that of copper, in order to obtain the same current-carrying capacity, the cross-sectional area of the aluminum wire will increase correspondingly, which increases the difficulty of welding.

The progress of ultrasonic metal welding technology makes it possible to widely use large square aluminum wire welding.


Aichie provides auto wiring harness , high voltage ev cable assembly and low -voltage auto wiring harness around the world. It has introduced new production equipment, which greatly improves the quality and efficiency of production. Customers are widely distributed in Europe and North America. Production employees and experienced engineering teams and sales teams serve our customers; please contact us now! We will provide you with competitive prices!


WeChat: 180 2750 2150

Tel: +86 180 2750 2150


GET IN TOUCH Subscribe-- Latest Catalog
once you subscribe our newsletter. we will keep you posted the latest catalog,Also will inform you the trendy news for the electronics and wire harness.

Leave A Message

Leave A Message
If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.