Did you know that a car has one mile (1.6km) of wire that weighs about 100 pounds (45kg)? The predominant material is copper due the attractive balance of conductivity and strength, which keeps the diameter small. Small diameter is key to packaging the bundles of wire passing through the doors, and from all electrical systems in the vehicle. The drawback on copper is cost, and with the growth in electric vehicles, the demand for copper is expected to increase by magnitudes.
With increased demand and limited supply, the cost of copper is increasing, and the automotive world is turning its focus to aluminum as an alternative. Aluminum has already established a lead position in heat sinks to extract heat from electrical systems, so the next logical frontier is the system that carries the electrical energy, the wire.
The first application of aluminum is battery cables as the size is larger, yet they are not bundled like the wire harnesses. When brake by wire comes mainstream, there will be another battery in the vehicle to provide the necessary redundancy in safety systems. Aluminum cables could offset some of the added weight of the dense and heavy battery.