The power shift: Embracing 48-volt systems in commercial vehicles

Vehicles have traditionally used 12- or 24-volt systems, but the shift to 48 volts is driven by the need for more power due to fuel economy regulations and new power-consuming components. In this episode, discover the future of vehicle electrification with Eaton’s eMobility experts. Joe Szczerba, Product Strategy Manager for embedded power and low-voltage power distribution, and Renan Perceguetti, Product Engineering Manager for 48V power conversion solutions, share insights on how Eaton is driving innovation in power conversion and distribution technologies. From portfolio strategy and system engineering to cybersecurity and functional safety, Joe and Renan discuss the challenges and opportunities shaping light vehicle and commercial applications. Tune in to learn how their expertise is powering the next generation of mobility.

To learn more and access all episodes, visit Eaton.com/10in10podcast

Transcript

JOE SZCZERBA: Welcome to the 10 in 10 podcast. I'm your host, Joe Szczerba, Product Strategy Manager for Low Voltage and Power Conversion at Eaton. Today, we're diving into the new power requirements being added to vehicles that are driving the need for more power and shifting the industry towards 48-volt systems. With me is Renan Perceguetti, Engineering Manager for 48-Volt Systems at Eaton. We'll discuss the benefits of switching to 48-volt systems, the key components involved, and the challenges manufacturers face during this transition. 

 RENAN PERCEGUETTI: Hello, Joe. Good to be here. 

 JOE SZCZERBA: Wonderful to have you. We have 10 questions in 10 minutes, so let's get started. The trend of electric vehicles has brought the discussions into hundreds of volts, and this opened new opportunities for modern technologies to grow. Does 48-volt generate the demand to grow a certain technology?

 RENAN PERCEGUETTI: Well, Joe, the 48-volt system actually came from a 12 and 24 volts type of architecture. So 40 volts comes as an option, to compare to high voltage systems, the development will happen in parallel, and the only thing we need is just protections. Everything needs to be graded to 40 volts. But other than that, if you already have a 12 to 24 volts type of application, it should be easy to ramp to 48 volts.

 JOE SZCZERBA: Can you explain the main advantages of 48-volt electrical systems compared to traditional 12-, 24-volt systems in commercial vehicles?

 RENAN PERCEGUETTI: Yeah. 48 volts in general comes to solve a power availability problem. You can do more with 48 volts. If you have a 12- or 24-volt system, you get more power in the same package. You're optimizing the battery and you're still under 60 volts, what's considered like a low-voltage, safe voltage to operate. And thinking on how everything operates, 48-volt the ratio of improvement, it's a squared ratio. So when you're moving from 24 to 48 volts, you're really making four times the improvement, not just doubling the overall power density, power availability of the system. 

 JOE SZCZERBA: So what are the main components of a 48-volt electrical system, and how do they contribute to overall vehicle efficiency?

 RENAN PERCEGUETTI: Well, as I mentioned, it's very similar to 12- and 24-volt systems. The architecture of the vehicle needs to be validated to 48 and that's when it comes opportunity to optimize the architecture you're bringing. You have to revisit your suppliers for fuses, for cables, for anything in between your 48-volt generator to your load. And you get a chance to update your components doing that. So that's the main benefit.

 JOE SZCZERBA: And what roles do regulatory bodies play in the adoption and implementation of 48-volt systems?

 RENAN PERCEGUETTI: There are no major regulatory bodies asking for a 48-volt solution. But what happens is, for example, emissions regulations are requesting OEMs to take some actions. That requires more power. And if you don't have a large battery, you have to find this power. And one of the options is to raise the voltage. So there's no regulation saying you need to be 48, but with those emissions regulations and asking for more power, more solutions that require power, 48 volts fits very well.

 JOE SZCZERBA: And how do 48-volt systems complement other technologies and solutions for new vehicle architectures, such as high-voltage batteries, electric motors, or hydrogen fuel cells? 

 RENAN PERCEGUETTI: 48 volts is a known technology. Haven't started like today or two years ago. It has been-- people wanted to add 48 volts for a while now. So there are a big range of availability of solutions right now. You can have supercapacitors, DC-DC converters, fuses, power protections, mild-hybrid applications, autonomous vehicles. And even when you're optimizing an internal combustion engine architecture, you can fit a 48-volt system there.

JOE SZCZERBA: Great. What are some of the challenges that manufacturers face when transitioning to 48-volt systems, and how can they be overcome? 

RENAN PERCEGUETTI: Yeah. Well, again, it's a transition, right? It's very similar to 12 and 24. You need a 48-volt power source, some kind of a generator or an alternator that generates 48. You need a storage system, a battery. Some customers are using a capacitor or a supercapacitor. You need a 48-volt fuse, some protection in your line. A DC-DC converter may be needed if you still have 24- or 12-volt loads. If you have a module on your vehicle that still operates on that, you would have to convert 48 to those voltages. But that's it. If you understand and if you have the need, 48 volts makes a lot of sense.

JOE SZCZERBA: OK. So, what are the best practices and lessons learned from implementing and testing 48-volt systems in commercial vehicles? And what are the areas for further improvement and optimization? 

RENAN PERCEGUETTI: Well, if you don't have the knowledge on 48 volts, I think one of the best practices is to find someone that does. A partner, someone that already has some kind of experience. It's similar, but still, you have more power available. How do you operate? How do you validate that? Is there a standard that does the validation that you used to 24 or 12 volts? So having a person that understands can simplify the process. Also, you need to find a supplier for your components that understands 48 volts. They have already worked with that in the past and can demonstrate they understand what you're doing.You have to focus on functionality, right-- what you're trying to solve-- and optimize your system for that. And make sure all the necessary components are there, right? You don't want to skip some protection, some kind of control needed to make it work. 

JOE SZCZERBA: Do you have any success stories for 48-volt systems that you can share? 

RENAN PERCEGUETTI: Yeah. Here at Eaton, we released in 2024, an e-heater controller system that was driven by CARB-24 emissions. This is a controller that gets the power generated from an alternator, 48-volt generator, and controls how much power we are driving to a heat element, basically, that is in the catalyst system of the exhaust system of the vehicle. So that's a good story that we have. Also, there are new opportunities-- 48-volt opportunities on the powertrain overall. But the e-heater controller is one of the good examples we have. 

JOE SZCZERBA: What role do you see 48-volt systems playing in the broader trend towards the mobility industry?

RENAN PERCEGUETTI: Well, if you compare it to an EV solution, 48 volts is still more cost effective. You can have more power density compared to 12/24V. You open your vehicle for new opportunities, right? As soon as you have a 48-volt bus, 48-volt alternator, that means you can power the whole vehicle at 48 volts. Optimizing your cables, making sure you have a single system available. It's an interesting solution, for sure.

 JOE SZCZERBA: And then final question, what future developments or innovations can we expect in the field of 48-volt electrical systems for commercial vehicles? 

 RENAN PERCEGUETTI: I mentioned that 48 volts is not new, but still, the OEMs adapting 48 volts are not many. It's still engaging. So we see the next 10 years, 48 volts showing up more and more. Now, we see OEMs talking seriously of having 48 volts available more in the commercial vehicle side. Now, we know already that some cars, passenger vehicles have it. Trucks are a good example, commercial vehicle, because emissions require some actions that require more power or density. We spoke about it today. But we will see that happening on two-wheelers, motorcycles, passenger vehicles, expanding that, as well. More on the mild hybrid type of application. Military applications, marine applications, we see those growing in the next 10 years, for sure.

JOE SZCZERBA: Wonderful. This has been great. Thank you for sharing your insights today, Renan.

RENAN PERCEGUETTI: Yeah, glad to be here, and thanks.

JOE SZCZERBA: To learn more about how we're helping commercial vehicle manufacturers in the transition to 48-volt systems, visit us at eaton.com/emobility.