The Evolution from Copper to Aluminum – Are you ready?

For a long time, Copper has been serving as the primary material for wiring of all types, from home wiring to automotive wiring. There are several reasons for the use of copper. First, it offers high conductivity with little resistance. There is only one material that offers better conductivity than copper silver but is not an affordable solution for wiring needs. Copper also offers decent length of life, though there can be corrosion problems when copper wiring is exposed to the atmosphere.

However, copper is being phased out in automotive electrical systems, particularly in wiring harness applications and especially for hybrid vehicles. Aluminum is the metal that is replacing copper. There are a number of reasons for this shift.

Benefits of Aluminum over Copper Automotive Cables

The first and primary benefit of aluminum over copper is the fact that it is far lighter. In comparison to aluminium copper is very heavy. Even in larger gauge applications, aluminum is lighter than copper. This is an important consideration for wiring harness applications with hybrid vehicles. Extraneous weight must be shed from all aspects of design and production to eliminate unwanted problems and to bring hybrid and electric vehicles into compliance with government regulations.

Because every ounce of additional weight on a hybrid car or truck affects fuel consumption and battery life, lighter metals are optimum. The lighter the metal, the lighter the wiring harness and other automotive cables will be. This translates to better fuel economy, better battery life and other benefits for end consumers, as well as for the environment.

The second important benefit of aluminum over copper is the fact that aluminum is more affordable than copper. Once, copper had been the most affordable metal on the planet, but that is no longer true. Increased demand from emerging nations around the world (India and China, predominantly), as well as reduced production from mining facilities on a global scale, have combined to push the price of copper ever higher. Aluminum, which was actually considered a precious metal in the past, has become more and more affordable as better mining and refining methods have been developed.

In fact, the cost and weight factors for copper make it very difficult to understand why the metal continues to be used for wiring harness applications and automotive cable needs. Overall, the use of aluminum to replace copper automotive wire harness cables promises to offer lower weight, better longevity, lower costs and reduced emissions from even hybrid vehicles, which are the lowest emissions vehicles on the market, barring full-electrics.

The Problems with Aluminum

However, the situation is not as simple as it seems. Before aluminium can replace copper in power supply systems, a number of technological challenges need to be surmounted. Wire harness manufacturers cannot simply retool their production lines to use aluminum rather than copper. There are hurdles to overcome here. The most significant factor here is heat. In high-heat situations, and there are many places in the modern automobile where that is the case, aluminum displays a distinct creep behaviour. Eventually the connections will come loose. Therefore, the first obstacle to overcome is to develop a connection method that will not come loose with aluminum “creep.”

One solution has been proposed here: The use of aluminum elements for cabling and copper elements used in connections. However, there is a problem with this situation as well. Copper and aluminum “do not get along well.” This means that there is a very high electrochemical potential between these two metals.

Therefore, if copper connections were used with aluminum cables, the resultant corrosion would make the entire system ineffective. In addition, joining copper and aluminum is not a simple or affordable process. As technology progresses, that may change, but the state of the manufacturing industry today makes this very difficult.

However, there is an intelligent connection method in development. Scientists from the Technische Universitaet Muenchen (TUM), in collaboration with BMW engineers, have now found out what tricks make it possible to replace copper with aluminium. In essence, this is a connection concept that uses an aluminum electrical connection, codenamed LEIKO.

LEIKO is essentially a sheet metal cage that enhances the stability of the connection and helps support the contact pressure spring, as well. This method allows the unwanted “creep” factor to become a benefit, rather than a detriment. For instance, because the contact elements are not responsible for holding the connection together in this scenario, the “creep” factor actually stabilizes the contact. The lifetime of this connection method is expected to be about 10 years, and should feature constant contact throughout the duration of its lifespan.

To read more about the evolution from Copper to Aluminum, download the article as a pdf-document here giving you further details.