The auto industry is in the middle of a revolution, one where new and emerging technologies are steering the market. Such high-tech features are placing a tremendous burden on the typical vehicle’s 12-volt electrical systems and for this reason we’re seeing a new trend: cars equipped with 48-volt electrical systems. Not every new vehicle will feature such systems, but for those that do, there are strong benefits for manufacturers, consumers and the environment alike.
Bentley’s Bentayga SUV utilizes a 48-volt system for its electronically controlled sway bar.
The Current Standard: 12-Volt Electrical Systems
Every vehicle’s electrical system is composed of a battery, starter and an alternator. Modern vehicles have 12-volt electrical systems, with the car battery serving as the center of that system.
Electricity flows out from the battery by means of the positive terminal through wires to power various components, including the starter. The starter stores a small amount of electricity to turn the engine, while the alternator helps keep the battery charged when the vehicle is running, by sending power back to the battery through the negative terminal.
Although 12-volt electrical systems have been the standard for decades, they’ve also been called upon to do more work in recent years, including powering water pumps and turbochargers, and to supply power to the computer, navigation and audio systems. As vehicles become more complex, manufacturers are exploring other options, including the 48-volt electrical systems.
Emerging Technology: 48-Volt Electrical Systems
There are two reasons why car manufacturers are planning for 48-volt electrical systems:
1) Such systems can handle more complex loads, including technologies related to autonomous vehicles.
2) Environmental benefits may be realized, through reduced emissions and improved fuel economy.
Suppliers such as Bosch, Continental, Delphi and Valeo are developing 48-volt electrical systems for manufacturers. These new systems will power such energy-intensive components as turbochargers, hybrid motors and stop-start motors, and supply electric power to the water pump, air conditioning, power steering and power brakes.
Does this spell the end of the 12-volt electrical system? No. In fact, future cars will likely run the two systems concurrently, with 12-volt systems powering the lights, center console, seats and windows, and 48-volt systems tasked with supplying energy for power-consuming components.
On the environmental side, 48-volt electrical systems will also allow manufacturers to transform some models into mild hybrids by replacing the starter with a 48-volt motor generator unit (MGU). Such vehicles would also gain a 48-volt lithium-ion battery pack and a DC-to-DC converter, creating the mild hybrid system.
A mild hybrid system utilizes both the gasoline engine and electric motor to power the car, with fuel savings of 15 to 20 percent possible. Like similar systems, mild hybrids offer another tangible environmental benefit: a reduction in emissions. In all, mild hybrids provide about two-thirds the benefit of traditional hybrids, but at just one-third the cost. Expect manufacturers to turn to such systems in an effort to meet ever-increasing federal fuel economy and emissions mandates.
You’ll currently find 48-volt electrical systems in a few models, including the Bentley Bentayga, which utilizes this system to power its electronic sway bars. While mechanically operated sway bars do a good job of reducing body roll in a turn, the electronic system is simply superior. That’s expected in a $230,000 super luxury SUV, but it’s only achieved with a 48-volt system.
The previously available Audi SQ7 TDI utilized a 48-volt system to power its turbo, and Audi’s Q8 Sport Concept with a supercharger also utilizes the system.
Like most new technologies, we’ll see this filter down to mainstream models as costs are lowered. Indeed, Honda is already using a 48-volt system in its European Civic diesel model. The system powers the Civic’s turbo, reducing lag time while improving acceleration and torque.
Coming to a Car Near You
Most manufacturers haven’t said how and when they’ll implement 48-volt electrical systems, but you’ll be hearing about them, especially if you follow the major auto show and technology circuits.
Indeed, at the 2017 Frankfurt Motor Show this September, manufacturers such as Peugeot, Volvo, Volkswagen and Mercedes-Benz revealed plans to shift away from diesels to mild hybrids. Notably, total manufacturing costs come in $600 to $1,200 lower than diesels and without the emissions challenges of the diesels, according to Automotive News. By 2025, the European forecast has more than half of all new vehicles equipped with such systems.
For North American enthusiasts, upcoming auto shows in Los Angeles, Detroit, and New York may very well reveal where this trend is going regionally. The CES (Consumer Electronics and Technology) Show held in Las Vegas in early January should also provide some details.