Why 800-volt electric cars are 'a really big deal'

Electric cars make up only about 10 percent of the global market, but already automakers and suppliers are preparing for the next generation of components, with solid-state batteries, axial flux motors -- and now, 800-volt electrical systems that promise to cut charging time in half, sharply reduce battery size and cost, and increase drivetrain efficiency.

So far, just a handful of cars use 800-volt systems, as opposed to the current 400-volt standard. Those in series production available in Europe include the Porsche Taycan, Audi e-tron GT, Hyundai Ioniq 5 and Kia EV6. Outside of Europe, the Lucid Air luxury sedan uses a 900-volt architecture (experts say it is technically an 800-volt system).

By the end of the decade, suppliers say, 800-volt architectures will be the dominant technology, especially as more and more dedicated full-electric platforms such as Hyundai's E-GMP and Volkswagen Group's PPE appear.

"In 2025, the majority of applications coming into the market will be 800 volt," said Dirk Kesselgruber, president of the electric drivetrain division at GKN, one of several Tier 1 suppliers that have embraced the technology. GKN is now offering 800-volt-ready components such as e-axles, with an eye to starting series production in 2025.

"We think it's going to be the mainstream, and Hyundai has proved that it can be competitive on price," Kesselgruber told Automotive News Europe.

Other suppliers echo his enthusiasm. 

"800 volt is the logical next step in the development of BEVs," Alexander Reich, head of innovation power electronics at Vitesco, said in an interview with ANE. Vitesco has recently landed big contracts for 800-volt enabled components, including supplying inverters for Hyundai's E-GMP platform, inverters to a major North American automaker and electric motors for a leading electric vehicle maker in China. 

"The 800-volt sector has grown faster than was expected several years ago, and we are seeing a lot of interest from our customers," said Harry Husted, CTO at BorgWarner, in an email to ANE. BorgWarner has won a number of 800-volt orders, including one for an integrated drive module for a Chinese luxury brand.

But what is so great about 800-volt systems compared with existing 400-volt ones? 

The advantages are numerous, experts say, deriving from the simple physics that they can deliver the same amount of power at a lower current. "By doubling the voltage and having the same current, you get two times the energy into a vehicle," Reich said. 

The main benefit is an approximately 50 percent faster charging time given the same battery size. As a result, batteries -- the costliest component in an electric car-- can be made smaller and overall weight is reduced, increasing efficiency. 

"There is no need for 1,000 km of range in an EV" if charging times are fast enough, Reich said.

Because higher voltages supply the same amount of power with less current, cables and wires can be made smaller and lighter, cutting down on consumption of costly and heavy copper. Less energy is lost, too, meaning better range and improved motor performance (also helped by lower weight). And there is less need for elaborate thermal management systems to ensure the battery is working at optimal temperatures.

And when paired with emerging silicon carbide (SiC) microchip technology, 800-volt systems can increase powertrain efficiency by up to 5 percent. Such chips lose less energy to switching, and are particularly effective for regenerative braking.

Because the new SiC chips use less pure silicon, costs are potentially reduced and more chips could be made available to the auto industry, suppliers say. (Other industries tend to use 100 percent silicon chips, competing with automakers for space at wafer fabs.)

"Putting everything together, 800 volt is a really big deal," Kesselgruber of GKN said.

But with most existing charging stations based on 400-volt systems, is there still an advantage for cars with 800-volt architectures? 

Yes, experts say, but they will need an 800-volt-based charging infrastructure to take full advantage. 

"Much of the existing DC fast charging infrastructure is for 400-volt vehicles," Husted of BorgWarner said. "To allow the faster charging that 800 volt enables, the latest generation of high-voltage, high-power DC fast chargers will be needed."  

This is not an issue for home charging, but the highest speed public charging networks are so far limited. "This is most important for public motorway chargers," Reich said. "The refill has to be as quick as fueling up at a gas station." 

"This is the use case" for 800-volt charging, he added. 

In Europe, such networks include Ionity, the multi-automaker (including Audi and Porsche) partnership with a number of 800-volt, 350-kilowatt highway charging points. 

"A 350-kw charger translates into five to seven minutes charging time for 100 km," said Otmar Scharrer, senior vice president electrified powertrain technology at ZF, adding that it was about the same amount of time it takes for a coffee break.

"This is really a game changer; this is something that will drive acceptance of e-mobility," he told ANE.

According to a recent report from Porsche, it takes about 80 minutes to add 400 km (250 miles) of range at a typical 50 kw 400-volt station; that time drops to 40 minutes at 100 kw. If the charging plugs are cooled -- adding cost, weight and complexity -- that time can fall to 30 minutes, Porsche said.

"A shift to a higher voltage is therefore inevitable in the quest to achieve charging times in the desired corridor" -- falling to about 15 minutes with 800-volt charging, the automaker said. Taking into account the time to pay, "the goal of 'charging like filling up' is thus nearly within reach," the report said. 

If fast charging times mean that ever-larger batteries are no longer needed to eliminate "range anxiety," what are the implications? 

Of course, automakers can opt to benefit from faster charging with the same battery pack, but with EVs still not yet at cost parity with internal combustion cars, a smaller battery may be a better choice, on philosophical as well as economic grounds, ZF's Scharrer said.

"It makes no sense" to equip a mainstream compact car such as the Ioniq 5 with a very large battery, he said.

In Scharrer's view, the ideal battery size for such a car would be 55 kilowatt-hours, in line with the smaller 58-kWh option offered by Hyundai/Kia (a 73-kWh pack is also available) -- provided charging times from 5 to 80 percent fall to 10 minutes. "It's quite a challenge but it has happened in the laboratory," he said.

A combination of 800-volt charging -- both in the vehicle and in the infrastructure -- as well as improved chips could make that a reality, he said.

"We have to ask ourselves as a society if it makes sense to use a lot of precious materials that we dig out from the earth like lithium or cobalt, with a lot of weight and a lot of cost just for one or two [long trips] every quarter," he said.

If 800-volt technology is so clearly superior -- and so inevitable -- why are nearly all electric cars still based on 400-volt systems, including those from market leaders Tesla and VW?

"It's a very reasonable question but difficult to answer," Scharrer said. The answer partly lies in convenience and precedent, he and other experts said. 

The typical home uses a 380-volt three-phase current (voltage rates are actually a range rather than a fixed number), so the charging infrastructure already existed when automakers began launching plug-in hybrids and full-electric cars. 

And the first wave of electric cars were built on components developed for plug-in hybrids, which are 400-volt based. "When you start with plug-in hybrids, you take the high-voltage experience into your first battery-electric vehicles," GKN's Kesselgruber said.

"When everybody started at 400 volts, I think the rationale was that this was an existing voltage level in infrastructure everywhere," he said. "It was available and accessible."

He credits Porsche, with its focus on performance rather than practicality, as being a pioneer in 800-volt systems.

"Porsche allowed themselves to rethink what we took over from the past -- Is it really the optimum, or can we design from scratch?" he said. "That's the beauty of being a performance car maker."

It's merely a matter of time before a wave of 800-volt EVs come to market, suppliers say. There are few technical challenges, they say, but components need to be developed and verified. Costs are something of an issue, but parity will come with scale, the prospect of smaller batteries and the use of less copper, they say.

Volvo (and subsidiary Polestar), Stellantis (Maserati, future large EVs) and GM (pickups) have said future models will use the technology. VW Group is planning a range of vehicles on the PPE platform, including the new Macan and a station wagon based on the new A6 Avant e-tron concept.

Many China-based automakers have announced they will move to 800-volt architectures, including XPeng, Nio, Li Auto and BYD, as well as Geely-owned Lotus, which just showed the forthcoming Eletre SUV.

"With the Taycan and e-tron GT, you have vehicles with top-notch performance, and then you have the Ioniq 5, which is completely designed to be a family car," Kesselgruber said. "If those two can manage this, then every vehicle setup can manage it."