Chances are good that in a few years you might end up driving a hybrid without even knowing it.
That’s because automakers are increasingly seeing the value of offering so-called mild hybrids – cars packing 48-volt batteries that power just about everything except the engine.
“It’s less of a difference than trying to get the consumer to buy a full hybrid or battery electric vehicle,” says Devin Lindsay, principal analyst in powertrain technologies for IHS Markit, a London-based information provider. “It’s a technology that most people won’t even notice is under the hood.”
IHS Markit expects Europe to lead the way, with mild hybrids representing 35 per cent of vehicles produced by 2025, followed by China and Japan at 33 per cent and 23 per cent, respectively. With its preponderance of larger SUVs and trucks, North America is seen lagging at 12 per cent.
German manufacturers are particularly seen as leaders in the space. This year, Audi announced that the technology would come standard in all cars equipped with its A8 engine, such as the A6. Mercedes also this year said it was adding mild hybridization to its E-class and CLS ranges. BMW confirmed late last year it is working on mild hybrids.
Asian makers are getting into the game, too, with South Korea’s Kia adding the technology to this year’s Sportage. Some U.S. manufacturers are on board, as well – the 2018 Jeep Wrangler and 2019 Dodge Ram are two examples.
Nevertheless, the technology is primarily being pushed by foreign companies in smaller cars, at least for now.
“You can call it a wave because they’ll be coming ashore from other regions,” Lindsay says. “Those manufacturers play much more heavily in the sedan space so that’s probably why we’re going to see more emphasis there.”
Mild hybrids are the veritable middle children of electrified vehicles in that their 48-volt batteries are more powerful than the standard 12.6-volt types found in most regular cars, but not as heavy-duty as the 300-volt-plus kinds in full EVs.
Definitions and exact capabilities differ by manufacturers, but mild hybrid batteries typically power everything in the vehicle short of propulsion, including electronics and climate control. As in full hybrids and electric vehicles, the batteries are recharged by the motor.
The extra power offered by such batteries is a necessary development given that cars’ electricity needs have grown dramatically in recent years, Lindsay says. Besides just the radio, climate system and power windows, current vehicles also typically feature large touch screens and a host of sensors, all of which are hungry for electricity.
Mild hybrids’ main advantage and duty, however, is the ability to quickly start-and-stop their engines while idle, which results in fewer emissions and better fuel economy. Kia, for example, says its 48-volt system improves fuel efficiency by 4 per cent in worldwide harmonized light vehicles test procedures and 7 per cent in the new European driving cycle tests.
Despite that, the start-stop effect can be jarring for drivers since it seems like the car is stalling out. Industry experts, however, believe this wrinkle is slowly being ironed out.
“The first time it does have a weird feeling, but you get used to it,” says Amir Khajepour, a professor of mechanical engineering at the University of Waterloo and the Canada Research Chair in Mechatronic Vehicle Systems. “I have seen progress in making it feel very smooth.”
Sedans will continue to be the focus for mild hybrid technology in the near term, he adds, because of the cost and complexity of batteries needed to power larger vehicles. SUVs and trucks also require bigger cables running throughout.
“That means size, that means volume, that means cost,” he says. “When you look at electric cars, the bottleneck is still the [size of the] battery.”
Ultimately, mild hybrids are seen as a necessary stepping stone on the way to full electrification.
“Car makers are facing new regulations all over the world for their fleet emissions, yet the public – aside from the early adopters – is still cautious … especially given the cost premium,” says Olivier Trescases, director of the University of Toronto Electric Vehicle Research Centre and Canada Research Chair in Power Electronic Converters.
“Mild hybrids allow automakers to achieve significantly lower fuel consumption without sacrificing range and with minimal incremental cost. … They represent a half measure towards the eventually mass electrification of urban transportation.”