Tesla’s electric pickup was eagerly awaited, and its release did not fail to be noticed. Among the many innovations, we find a paradigm shift in the low-voltage battery. 12 volts gives way to 48 volts. This is the first car to pass this milestone. Let’s see what this changes for the future of electric cars.
Elon Musk’s firm has indeed finally released the famous Cybertruck, presented in 2019. Four years later, the beast is very real, and what a beast! If its design leaves no one indifferent, it is perhaps not the biggest revolution of this extraordinary vehicle.
Indeed, the architecture of the low-voltage battery — the one that is usually under the front hood of a car, not the one that is used to power an electric car — is for the first time on a car in 48 volts instead of 12 volts. This change had been announced at the Investor Day conference in March 2023, but had been able to go under the radar until now. It is the first production car to abandon 12 volts in favor of 48 volts.
Now that the Cybertruck is available, some observers may begin to see the implications of this shift to 48 volts. The rest of the industry has also received documents from Tesla to try to initiate a change for the future of electric mobility. But what will the transition from 12 to 48 volts for the low voltage battery really change?
The low voltage battery: what is it for?
In an electric car, the traction battery which is used to power the motors is not the only battery. As on a thermal vehicle, we find a so-called low voltage battery, used to power all the accessories. This includes the headlights, the central screen, but also the heated seats or the vehicle’s multiple speakers.
This low-voltage battery is recharged by the traction battery when needed, so as to maintain its optimal charge level. At Tesla, a small revolution has already taken place on this 12-volt battery, since in 2022 the brand abandoned the good old method of a lead-acid battery, and switched to lithium-ion.
Given everything that low-voltage battery powers, there’s an awful lot of cable to run. Indeed, the 12V power supply must go to each speaker, in each door, but also to the ceiling to power the ambient lights, etc. There are therefore hundreds of meters of cable to pass through a car, and it all ends up weighing.
Economies of scale… but not yet
The automotive industry has been using 12 volts as the standard for low-voltage batteries for nearly 70 years. A machine like this isn’t going to change its tune overnight, so you have to imagine that we’ll continue to see 12 volts almost everywhere in the coming years. Tesla’s goal is to achieve economies of scale through a very simple principle of physics: by increasing the voltage, you can lower the current to obtain the same power and therefore reduce the size of the cables.
Ohm’s law is indeed on Elon Musk’s side, since by going from 12 to 48 volts, Tesla announces that it can use half as much copper compared to a 12-volt architecture in the Cybertruck, reducing the total amount of cables needed for the electric pickup by 77%.
Unfortunately for Tesla, being an exception in the automotive world for the moment, the brand must manage on its own to supply itself with spare parts for its 48-volt architecture. For example, while almost all 12-volt controllers are purchased in bulk from subcontractors, the 48-volt controllers required for the Cybertruck were designed in-house for the most part. In fact, only 15% of the controllers could be purchased elsewhere.
All this work involves a significant cost in research and development, which will only be worthwhile if these controllers can be reused in the future. We can well imagine that the brand has a lot of ideas, and that its manufacturing processes for other models (notably the future Model 2) will benefit from this.
Tesla’s idea behind sharing its documents on how to design a vehicle with a low-voltage 48-volt architecture is to try to get everyone moving in the same direction so that the entire supply chain switches. Time will tell whether Tesla was right ahead of the curve and initiated a change throughout the industry, as it did with its proprietary connector in North America, for example.
The Cybertruck likely won’t be the only vehicle to switch to 48 volts
As mentioned above, what Tesla officially calls “the next generation of vehicles” and which we imagine to be the Tesla Model 2 should benefit from a low-voltage architecture of 48 volts as well. For the moment, the brand is focused on ramping up the production lines for the Cybertruck, and this should still be the case for a few years. But after 2025 and 2026, we can imagine that it will be time for Tesla to unveil its new big project, with significant production volumes, probably around 3 million vehicles per year at the very least.
The brand’s current vehicles will have all benefited from multiple hardware updates, as is usually the case with the Model S, Model 3, Model X and Model Y since their release. Difficult to say if the 48-volt architecture will have already been extended to these vehicles before being pushed onto the future, more affordable car from Elon Musk’s firm.
Among the advantages of moving away from the 12-volt low-voltage battery, there is of course independence from various subcontractors, something that is dear to Tesla. Indeed, the brand generally makes a point of developing most of the components internally, in order to keep control over costs and not depend on a third party for its production. This was particularly evident during the semiconductor crisis, where Tesla seemed much less impacted than other manufacturers, who were often forced to stop delivering vehicles while waiting for certain parts.
Furthermore, the economies of scale would be very visible if we start talking about several million vehicles per year, where the few thousand Cybertrucks produced in 2023 will rather cost the brand a lot of money. No doubt Tesla’s engineers and financial managers will agree on the right time to start implementing 48 volts on the rest of the vehicles, weighing the pros and cons.
Production lines will probably need to be modified, which means a production shutdown. At Tesla, production is still in full swing right now, and it’s not really a good time to take a break. But in a few years, with a well-established Cybertruck and state-of-the-art factories running smoothly, it’s possible.
Towards broader future uses
As we saw above, Tesla will undoubtedly gradually generalize the use of 48 volts throughout its range. Elon Musk’s desire to launch a turning point in the industry is very real, as evidenced by the manufacturers having received the guide to produce a vehicle with a 48-volt low-voltage battery.
Ford’s CEO, for his part, indicated that his development teams were working on a 48-volt architecture, and were even on a similar path to that chosen by Tesla. The next decade could therefore see many manufacturers take the plunge, especially considering how well 48-volt batteries seem suited to future uses.
Tesla has not yet managed to implement PoE (Power over Ethernet) in the Cybertruck, but it is one of the uses envisaged with a single cable for power and data, something precious in a car loaded with cameras, speakers and other accessories communicating with the onboard computer.
The revolution brought by PoE in vehicles is incompatible with a 12-volt battery, since the intensity would be far too high to power the various components. In 48 volts, however, there is no longer a problem, and the total length of cable required is thus halved: in short, this translates into savings and weight gain.
Some also highlight the fact that the transition from 12 volts to 48 volts would make a lot of sense in many areas, beyond automobiles. The USB standard in particular provides that with an intensity of 5 amps, we can increase power to 240 W, and the most keen among you will have noticed that to do this, the nominal voltage must be 48 volts (48 x 5 = 240).
There is still a long way to go for what happened with Tesla’s Cybertruck to be democratized and little by little to find its place throughout the industry, and why not in other areas as well, but it is more than likely that the electric pick-up has started a trend.