What You Need to Know About a Mild Hybrid

Give your commute a battery boost with this simple and efficient technology.

Benjamin Hunting | 

Jun 20, 2023 | 2 min read

Jeep

Mild-hybrid automobiles — which feature a 48-volt architecture — are becoming increasingly common across brands. These low-voltage hybrid systems can efficiently handle and store energy while improving fuel economy and reducing emissions, but without adding large cost increases to gas or turbo-diesel vehicles. 48-volt mild hybrids are a stepping stone between internal combustion and full hybrids.

Here are some important facts to keep in mind before you park one in your driveway.

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Mild Hybrids Cars: Simpler Than Standard Hybrids

Compared with traditional hybrids, a 48-volt mild hybrid can be considered entry-level electrification. In broad strokes, a 48-volt mild hybrid can recover energy generated while braking and store it in a battery. It then feeds that energy to a small electric motor that takes the place of the vehicle's starter. In almost every example, this motor is used to provide a horsepower boost that reduces the load on the internal combustion unit, and results in improved fuel efficiency. At highway speeds, it can also allow the car to coast while the gas engine idles.

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Low or No Maintenance

As you might have guessed, this simplicity helps reduce the need for additional maintenance related to the hybrid system itself, because electrical components have few moving parts that could require repairs over the course of ownership.

The batteries used in 48-volt mild hybrid systems are also considerably smaller than a standard hybrid's. As a result, they cost far less to replace if they fail. Some batteries cost as little as $1,000, and prices may continue to fall as manufacturers develop more efficient ways to produce them. It's also common for 48-volt batteries to be covered under lengthy warranties, such as the 8-year, 80,000-mile coverage provided by Jeep for the Wrangler eTorque.

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Just Like a Regular Vehicle

There's nothing about how a 48-volt mild hybrid works that would keep you from using it just as you would a conventional vehicle. Because while the drivetrain operates at 48-volts, the vehicle's accessories, lighting, and infotainment, operate at 12 volts, as there's also a standard battery on board. This means you can plug 12-volt devices into its power outlets, use your vehicle to jump-start another car or truck, or be jump-started if your battery dies.

Keep in mind that extremely cold weather can affect a 48-volt battery the same way it would a 12-volt or traditional hybrid power pack. That means you may see a reduction in fuel efficiency during winter months.

Benjamin Hunting

Nearly two decades into his career as an automotive journalist, Benjamin has had his hands greasy, his hair blown back, and his heart broken by more than one project car. In addition to his work at Capital One, he has contributed features and reviews to Motor Trend, Car and Driver, Hagerty, Driving Line, Inside Hook, Super Street, European Car, Roadkill Magazine, Motor 1, The Drive, the Toronto Star, the National Post, Business Insider, NAPA, Autoblog, Automotive News Canada, and AutoGuide. He is also cohost of the Unnamed Automotive Podcast and cocreator of the Code 45 and Dead Air graphic novels. In his spare time, he's a friend to vinyl and enjoys keeping the shiny side up during track days.