Automotive News: EV industry seen shifting to 800 volt technology.

The amount of conductor copper needed varies with the square of the voltage.
For example a 1200W, 12V, 100A line with 10% loss drops 1.2V with 12 milliohm resistance.
Vs a 1200W, 120V, 10A line with 10% loss drops 12V with 1.2 ohm resistance.

So going from 400 to 800V drops the copper needed in the wiring and the motor windings by up to a factor of 4.
That plus up to 2X reduction in resistive losses in the controller transistors.
I don't see how it makes any direct difference in performance of the cells themselves.
 
No, of course it doesn't. We're seeing a journalist trying to be an engineer.
How safe is it for the public to be handling and abusing 800 v charging cords with their bare hands, if that’s what they are talking about? Even with 120/240 v 10 gauge public charging cords, I see them tied in knots, apparently on purpose to try and destroy them. Or the handles damaged by running over them or whatever else any random person can think of to do to them.
The safety present in EV charging systems is already much better than many if not all other electrical systems a person might encounter maliciously or otherwise. The battery potential in an EV is entirely isolated from ground intentionally to complicate the possibility of touching both sides at the same time. The car and charger monitor this isolation and of course can drop their relevant contactors as needed. This is one of the reasons why EVs still have 12V batteries, supporting safety systems while the traction battery is disconnected.

A DC charger does not present a voltage potential at the plug until it's happy an EV is connected.
With AC charging the communications with the EV is far more primitive than with DC but the entire purpose of the EVSE (what's commonly known as a 'destination', 'home' or 'portable' 'charger') is to present a higher level of safety at the EV connector over the little to none already present on the AC supply. Generally that means an RCD/GFI device, often one that can also detect DC imbalance on the AC line.
 
This quote makes no sense to me.

E = I R ; P = I E

Double the voltage indeed halves the current for the same power so that makes sense.

What is two times the energy? I don't understand that at all.
It goes quad if the resistance is the same and you don't care how much current go through it. If your need to limit the current to be identical then you can only double the power.

P = V^2 / R. Same equation just swap some variables around.

I personally don't know if Silicon Carbide chip will actually be cheaper than just Silicon chip for power electronics. The math they use seems to be assuming that since you can charge faster, you can use a smaller battery with a smaller range and just charge more often and faster. Is it going to work? Maybe. We'll see when it hits the market. We have to see in the end how those funny fuzzy math works out in the market.
 
The CCS Combo connector can only support 200 amps and that is the limitation 800 V gets around. At least for now ...
 
The article is disingenuous. While progress is being made, whether the battery pack is 400 or even 1000 volts makes ZERO difference to each cell's charge rate. It's pretty well understood that an overall 1C charge rate (1 hour) limits cell damage. There is a valid reason manufacturers limit charge rates.
+100. Bingo, we have a winer.

Cujet you beat me to it.

Sure if the connector to charge the vehicle can't handle the power then going to a higher voltage would allow more power without having to go to elaborate cooling means. But in all likelihood the connector isn't the real limiting factor. It's how fast the batteries can accept the charge that is the limiting factor. And putting them all in series and supplying the vehicle with a higher voltage to charge with is not going to improve how fast is a cell can accept its charge.
 
+100. Bingo, we have a winer.

Cujet you beat me to it.

Sure if the connector to charge the vehicle can't handle the power then going to a higher voltage would allow more power without having to go to elaborate cooling means. But in all likelihood the connector isn't the real limiting factor. It's how fast the batteries can accept the charge that is the limiting factor. And putting them all in series and supplying the vehicle with a higher voltage to charge with is not going to improve how fast is a cell can accept its charge.
I "think" it depends.

If the pack is designed for it, they can put more cell in it, or trade off capacity for charge rate, if the charging infra supports it. There is no incentive to design for higher charge rate than the infra so they may go for cost reduction, however if the charging supports it, then they may design the pack to have more cells, each charge that 1C max, and reduce the capacity, to get that "we are faster charging so we can use a smaller pack to save money" statement made.

In the end IMO it is the cost that matters, always.
 
imho, battery should be 50-100 range max.
rest shall be h2 and fuel cells.
because huge batteries increasing too much weight and metal prices..
 
I "think" it depends.

If the pack is designed for it, 1) they can put more cells in it, or, 2)trade off capacity for charge rate
2) So far, we have been utterly unable to achieve those promised "epic" rates of charge. The (roughly) 1C charge rate remains, and will remain for the near future.

1) However, you are absolutely correct, a bigger battery pack can accept more power at the 1C rate. Add 20% more 2170 cells to a Tesla Model 3 and we can now pump 20% more power into it while charging.

Note: My example above of 20% more cells seems problematic, as there is no underfloor room for such, and taking up trunk space would not be ideal. Nor would the additional 400 pounds be beneficial.
 
When will some learn that faster rate/higher input isn't always the answer? Usually leads to more volatility and less usable lifespan. Of course the 'naysayers' will go on and on about upcoming battery technology, but it isn't evolving/improving that quickly.
Battery technology keeps changing at amazing rates. I wonder about battery life with such high voltages. Hydrogen power for electricity is also a big thing going on at the moment.
 
Battery technology keeps changing at amazing rates.
I'd like to suggest the opposite. I had a thread here about bogus battery breakthroughs, which started some heated discussions. However, I was able to make the case that electrochemical energy storage has finite and quantifiable limits. The promise of a battery with greatly improved energy density is an alluring one, that's for sure. It's led to hundreds of billions in research. Result? We still use the 18650, the 2170 and various pouch/prismatic cells, albeit with refinement.

What we do know is that batteries move ions, and we can only move so many. That's because there are only so many to move. Want more power? Make the battery physically larger, or make some of the internal components smaller. Both methods (larger like the Tesla 4680, and smaller internals like the Solid State designs) have finite limitations. Remember, Lithium contains the highest number of ions.

Note: Tesla's seemingly ever improving range numbers are largely due to adding more cells.
 
Each cell still only sees a low voltage, typically in the range of 3.15 to 4.15 V.
I was thinking about the initial surge when first plugging in. The BMS would have to be really something special. I noticed a few places to charge in my small town now.
 
I was thinking about the initial surge when first plugging in. The BMS would have to be really something special. I noticed a few places to charge in my small town now.
The BMS controls either the EV's on-board charger or a DC public charger to follow predefined charge current curves based on battery temperature and present state of charge. There's no surge, it's all carefully managed.
 
Automotive News: EV industry seen shifting to 800 volt technology.

It's a subscription site so I'm pasting the article...

Electric vehicles make up only about one-tenth of the global market. But 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 new vehicles use 800-volt systems, as opposed to the standard 400-volt technology. Among the examples reaching the market: the Porsche Taycan, Audi E-tron GT, Hyundai Ioniq 5 and Kia EV6. The Lucid Air luxury sedan uses a 900-volt architecture, but experts say it is technically an 800-volt system.

EV component suppliers say that by the end of the decade, 800-volt vehicle 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 thIMG02e electric drivetrain division at GKN, one of several Tier 1 suppliers that have embraced the technology. GKN is 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," he 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 the publication. Vitesco has landed big contracts for 800-volt-enabled components, including supplying inverters for Hyundai's E-GMP platform, inverters for a major North American automaker and electric motors for a leading EV 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," Harry Husted, chief technical officer at BorgWarner, said via email. The supplier has won a number of 800-volt orders, including one for an integrated drive module for a Chinese luxury brand.

Why the change?
What's so great about 800-volt systems compared with existing 400-volt ones?

The advantages are numerous, experts say, starting with the premise 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 for the same battery size. As a result, batteries — the costliest component in an EV — 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.

At the same time, 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.

When paired with emerging silicon carbide 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 silicon carbide 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 full silicon chips, competing with automakers for space at wafer fabs.

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

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

Experts say yes, though vehicles 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," said BorgWarner's Husted. "To allow the faster charging that 800 volt enables, the latest generation of high-voltage, high-power DC fast chargers will be needed."

That's not an issue for home charging, but the highest-speed public charging networks so far are limited. Reich believes it will be a particular issue for highway charging stations.

"The refill has to be as quick as fueling up at a gas station," he said. "This is the use case" for 800-volt charging.

Europe is seeing the rise of such networks.

Ionity is a multi-automaker 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. That's about the same time as a coffee break, he pointed out.

"This is really a game-changer," he said. "This is something that will drive acceptance of e-mobility."

According to a recent report from Porsche, it takes about 80 minutes to add 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," the report said. It would fall 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."

Audi says the A6 Avant E-tron concept, based on the same PPE architecture as the Taycan, can take in enough energy in just 10 minutes at a fast-charging station to drive about 186 miles.

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

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 vehicles, a smaller battery may be a better choice — on both philosophical as well as commercial 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 vehicle would be 55 kilowatt-hours, in line with the smaller 58-kWh option offered by Hyundai —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.

Cautious transformation
If 800-volt technology is indeed superior and inevitable, it's worth asking why nearly all EVs are still based on 400-volt systems, including those from market leader Tesla and from VW.

Scharrer and other experts believe the answer partly lies in convenience and precedent.

The typical house 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 vehicles. And the first wave of EVs were built on components developed for plug-in hybrids, which are 400-volt-based.

Automakers and suppliers agree that there are advantages to faster-charging 800-volt architectures. The question is when will the technology arrive.
Thanks. Great article/explanation.
 
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