But 12-volt systems are becoming inadequate for modern vehicles, says Sam Abuelsamid, a senior analyst at Navigant.
“We’ve got so many things in the vehicle today that are demanding electrical power,” he says, from advanced safety technology to convenience features.
That’s why automakers including Fiat Chrysler Automobiles (FCA), Mercedes-Benz, and Volkswagen have started designing vehicles using 48-volt systems, which CR calls mild hybrids. The technical changes are relatively minor. Cars get an electric generator instead of an alternator, and a larger battery and regenerative brakes.
Why are they making the change? Because a 48-volt system can save fuel, reduce emissions, and increase power, which helps automakers meet stricter worldwide fuel economy and emissions standards without sacrificing performance. Beyond the power boost and fuel savings, 48-volt systems don’t add as much up-front cost as true hybrids, such as the Toyota Camry Hybrid.
“The addition of 48-volt batteries can be good value for consumers because they support the latest tech features and boost fuel efficiency at a reasonable price point,” said Shannon Baker-Branstetter, senior policy counsel for energy and environment at Consumers Union, the advocacy division of Consumer Reports.
For example, a 48-volt system comes standard on the 2019 Ram 1500 outfitted with the smaller 3.6-liter engine. It adds only $800 to a Ram equipped with the larger 5.7-liter V8 engine, and it can boost fuel economy up to 10 percent, FCA says. It also adds up to 130 lb.-ft. of torque, which translates into better initial acceleration and more power for hauling and towing.