The switch to 48V

A revolution in the automotive industry

The automotive industry has long been anchored in the 12-volt electrical system, a standard adopted in the 1950s. Even with the emergence of hybrid and electric vehicles, which use high-voltage traction batteries, 12 volts remains ubiquitous for powering components such as window regulators, seat motors and headlights. However, the move to a 48-volt system, although already underway with some light hybrid vehicles, marks a significant new stage, particularly with companies like Tesla pushing this development.

Why switch to 48V?

The main advantage of adopting a 48-volt system lies in the technical benefits it offers. According to Ohm's law, the voltage is equal to the current multiplied by the resistance (V=IR). By increasing the voltage, we can reduce the current required for the same power, which means we can use thinner cables, reducing the weight of the vehicle and the associated costs. In addition, lower current also means less energy loss in the form of heat, which improves the overall efficiency of the vehicle.

Historically, the industry migrated from 6-volt to 12-volt systems in the 1950s to meet the growing power requirements of electrical components, including ignition systems for high-compression engines. Today, with the addition of countless electrical features in modern cars - heated seats, heated steering wheels, adaptive suspension and more - the demand for energy is even greater, justifying the move to a higher voltage.

Complex and slow change

However, the widespread switch to 48 volts does not happen overnight. The entire supply chain and design infrastructure are deeply rooted in 12 volts. Changing this paradigm means not only high costs for carmakers, but also a reassessment of the safety and compatibility of the new systems.

In the 1990s and 2000s, efforts were made to adopt high-voltage systems, but these did not lead to widespread adoption. Manufacturers found ways to optimise existing systems to avoid the additional expense of moving to higher voltage. It is only recently, with the addition of many power-consuming systems, that the adoption of 48-volt systems has begun to gain momentum.

Sometimes risky pioneers

There are always players in the industry who are ahead of their time, prepared to take risks to initiate change. Tesla, with its adoption of 48 volts for the Cybertruck, is a striking example of this. Tesla's choice is not just about reducing the weight of wiring harnesses, but also about introducing innovations such as steer-by-wire that might not be possible with a 12-volt system.

However, this transition is not without its challenges. Most of today's electrical components still operate on 12 or 5 volts, and it is costly to replace or redesign them to be compatible with 48 volts. In addition, 48-volt systems require more robust connectors and protection to minimise the risk of arcing, which adds further complexity.

Conclusion

The switch to 48 volts represents a major step forward for the automotive industry, bringing improvements in energy efficiency and weight reduction. However, the transition is far from straightforward. Challenges relating to existing infrastructure, development costs and the integration of new technologies make the changeover complex and slow. Despite this, it is clear that industry pioneers, who are prepared to take risks to initiate these changes, play a crucial role in the evolution of the sector.