The automotive industry embraced 12-volt electrical systems in the 1950s, and this standard has persisted across various vehicle types, including hybrids and electric vehicles (EVs). Even modern EVs with high-voltage traction batteries continue to incorporate a 12-volt battery for operating essential functions such as window regulators, seat motors, and headlights. While there have been instances of 48-volt “mild-hybrid” vehicles, Tesla’s Cybertruck marks the first instance of a pure EV utilizing a 48-volt electrical system.
In an interview, Elon Musk emphasized the industry’s long-standing adherence to the 12-volt standard, expressing his passion for addressing its limitations. Tesla took the initiative to send a manual on building a 48-volt car to major automaker CEOs, a move confirmed by Ford’s Jim Farley on Twitter. This echoes Tesla’s trend of pioneering innovations that compel other companies to catch up, such as over-the-air software updates and Gigacasting.
The transition to a 48-volt system is justified by the application of Ohm’s Law, where higher voltage reduces current, allowing the use of smaller wires, leading to weight and cost savings and improved vehicle efficiency. The automotive industry considered higher voltage standards in the 1990s and early 2000s, anticipating the need for increased electric power. However, the widespread shift to higher voltage did not materialize due to found efficiencies elsewhere and cost considerations.
The late 2000s saw the addition of numerous power-consuming features in cars, prompting some automakers to adopt 48-volt systems. Although 48 volts may enable smaller wiring, there are practical limits, and the systems require stronger connectors and shielding. The Cybertruck’s shift to 48-volt electrics is presented as a continuation of Tesla’s trend of groundbreaking decisions, offering potential benefits in weight reduction and efficiency.
Examining the Cybertruck’s components, it’s noted that while some are 48 volts, others, like the audio amplifiers, operate at 24 volts, and provisions exist for jump-starting with a 12-volt battery. Tesla claims a reduction in wiring harness weight and complexity, partially attributed to a new Etherloop data system. The 48-volt system also facilitates the use of steer-by-wire, a first in a production car without a traditional steering shaft.
However, questions arise regarding the necessity of a 48-volt system in an EV. Unlike internal-combustion cars, EVs already operate at higher voltages (typically 400 volts and up), making the advantages of a 48-volt system less clear. While Tesla emphasizes benefits like reduced wiring weight and the introduction of steer-by-wire, critics question the practical significance of these changes in the context of electric vehicles.
