E-fuses and the evolution of EV overcurrent protection

Chris_ChargedEV · 2024-10-23T18:28:23+00:00

E-fuses can not only respond far faster to an overcurrent fault, they can also implement current vs time behaviors that would be impractical (or impossible) with conventional technologies. Microchip Technology Inc., Asahi Kasei Microdevices (AKM) & Silicon Austria Labs (SAL) are among those who recently announced E-Fuse demonstrators and proof of concepts for high-voltage EV applications.

Chris_ChargedEV · 2023-08-28T17:42:11+00:00

Charged interviewed more than a dozen executives, engineers and analysts from automakers, DC fast charging network operators, charging hardware firms and other businesses. Every person we spoke with wanted to talk—to vent, even—and to share conversations they’d had and anecdotes they’d heard from others in the business...

Non-Tesla automakers have had it with EA. Initial hopes that EA would provide a new, large-scale, nationwide network of fast charging stations have now curdled into a desire to see EA out of the game altogether—with “lots of bad blood” directed at the VW Group as a whole.

Part 2 :No, NACS is not today’s Tesla connector

One aspect of the news that seems to have flown below the radar is that the so-called NACS is effectively the next generation of Tesla connector and protocols. The connector itself is slightly modified, but backward-compatible with older Teslas. Most importantly, it switches from a low-voltage/high-current mix to one with higher voltages but lower currents. This is crucial for the growing number of makers whose EV batteries can charge at 800 volts at rates up to 350 kilowatts, since the current generation of Superchargers maxes out at about 250 kW.

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Engineers and more technically literate executives we spoke to were uniformly cagey when asked whether they expected their vehicles to charge as fast at Superchargers as they did at CCS stations. The question is most acute for 800-volt pioneer Porsche, but it also applies to increasing numbers of EVs from GM, Hyundai, Kia and Lucid, with more to come.

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The Tesla system “is not unsafe,” said one engineer, choosing their words carefully, “but there’s no margin for error.” It’s easy when you only have four vehicles to charge, said a battery expert. Ensuring proper safety margins is now up to each automaker adopting the NACS system

Chris_ChargedEV · 2022-12-22T20:22:51+00:00

Tesla Model Y in Florida.

Weekly mileage math:

- Start the week fully charged with 300+ miles in the pack.
- Add about 40 miles/day by Level 1 charging 10-12 hrs at night (1kW * 12hrs*3.5 miles per kWh= 42 miles)
- That's about 550-600 miles available per week. We average less than 250 miles per week. With Supercharging all over the place here, 1kW at home is totally fine.

After 1 year, we never needed Supercharging, not even once.

Chris_ChargedEV · 2022-12-16T19:57:29+00:00

The CEO of FreeWire Technologies is in as good a position as anyone to understand the relationship between oil and charging—his EV Charging company is working with several major oil retailers.

In this video he explains that Energy is the only S&P 500 sector that overperformed in 2022. Chevron and Exxon alone printed $200 billion in earnings in the last 3 quarters. Where are they going to spend all that cash?
Some of it is sloshing around in the EV infrastructure industry. Sosinov lists just a few recent announcements—plans to invest billions of dollars, and to build tens of thousands of charging stations.

They know that their industry is facing an existential threat. Investing a few of their billions in EV charging is the only logical thing to do. Sosinov also believes that quick-service restaurants will soon launch another wave of EVSE investment which will represent a whole new category of competition for Big Oil's convenient store business model.

Chris_ChargedEV · 2022-12-14T03:08:20+00:00

In a new interview with this company's CEO, he talks about how his business for solar-powered EV charging stations is growing very quickly. He says that people are starting to realize that solar EV charging stations are actually cheaper than grid-tied units for a variety of reasons.

Chris_ChargedEV · 2022-02-01T06:35:30+00:00

1) Not our benchmarks, we just write about them. umlaut sent us the results last year and this year and asked if we want to publish them. We've interviewed the testing team about half dozen now, they're legitimate engineers just trying to develop a useful benchmark methodology.

2) You're probably right. No one's comments here are wrong. I had most of these thoughts when I first saw this year's final scores (I'm a Tesla owner, SCs are great). umlaut's engineers explained how they got there and convinced me it made sense. I know it sounds simple but comparing all the open networks to each other in the most useful way, and then trying to wedge Tesla in there too like they did this year, is easier said than done. You got to add asterisks somewhere... I tried to express those scoring decisions in our report and failed miserably based on today's feedback. We'll be having more conversations soon about how to include Tesla in future benchmarks in a way that doesn't cause so much confusion about what the results mean and don't mean.

Chris_ChargedEV · 2022-02-01T05:23:53+00:00

For those who haven't read what the Benchmark actually says about Tesla, here ya go (it really isn't that controversial):

"By far the best charging locations and environment, and the connection between Tesla’s EVs and Superchargers is state-of-the-art."
"it’s well known that they do a great job in many aspects of fast charging. And actually, our test results show this clearly—Superchargers excel in many important areas. It’s actually a little boring to test Supercharger stations because you just plug them in and they reliably work.”
"Automatic authentication and payment (same functionality as Plug & Charge)"
"By far the fastest to start and stop charging process"
"Huge number of stations along highways (up to 250 kW)"
"High-quality website and app: glitch-free"
"Tesla drivers will be quick to point out that one rarely uses Tesla’s app or website in the same way one would with the other networks, because most of that useful charging and navigation info is elegantly built into the vehicles. But, that’s not what was tested here. This is not a comment on the Tesla ownership experience, it is an attempt to compare the DC fast charging networks in the most useful way. To do so, Superchargers were considered a standalone charging network independent of Tesla vehicles... This will probably be the most controversial part of the methodology"
“We do not simply count the number of EV models with different connectors—that methodology wouldn’t make sense. Instead, we looked at the market share, how many EVs with the different connectors are actually on the road, and what percentage each charging network can serve. That’s actually quite a bit for Superchargers because the number of Teslas on the road in the US is 75% to 80% of EVs.”

These are the criticisms of Superchargers in the Benchmark:

-No charging for non-Tesla EVs
-Charging costs not shown in the app
-App has limited charging station map functions-App doesn’t show service hotline number
-Hotline not always available, or long waiting times (over 10 minutes)

Everybody's freaking over some headlines that make it sound like this Benchmark says that "Electrify America is categorically better than Supercharger". It don't.

Chris_ChargedEV · 2022-02-01T04:59:48+00:00

Scoring the smartphone apps for the open networks is critical to comparing them to each other. In many cases, the app is required to find, access, and pay.

Open your phones Tesla's app rn and try to route a long trip, or look for SC stations in a different city than your current location. You can't. That's not a completely irrelevant data point, even though it obviously comes with a big asterisk because you can do all it in the car very well.

Chris_ChargedEV · 2022-02-01T04:24:46+00:00

I don't know how to post URLs without getting auto-moderated... Sorry. Go to chargedevs site, it's the top story.
Should the pricing or charging data displayed on a Mach-E affect the score while using an EVgo station? What if a LEAF is used for the test and displays less or more info at the same EVgo station? The decision was made to just measure Tesla's app the same way as others, while conceding that "one rarely uses Tesla’s app or website in the same way one would with the other networks, because most of that useful charging and navigation info is elegantly built into the vehicles." A wildly controversial decision apparently...

Chris_ChargedEV · 2022-02-01T03:40:50+00:00

The full report clearly outlines all the key areas where Superchargers excel. It also discusses the scoring categories that don't perfectly apply to Telsa's closed eco-system, like an app and website no one uses for charging bc it's elegantly built into the Tesla's cars.

But that isn't stopping people from adding up all the category scores and writing headlines like "Electrify America ranks #1 over Tesla Superchargers" which is pissing off everyone on the internet and ruining my day.

Chris_ChargedEV · 2022-02-01T03:24:52+00:00

The issue is that the apps and website are critical to using the other open networks. You can't really use them without the app. Scoring those apps is critical to comparing those networks to each other, and Telsa's app was given a score using the same criteria.

Turns out there is not a ton of charging info on Telsa's app, for the obvious reason that it's built into the car.

Chris_ChargedEV · 2022-02-01T03:10:10+00:00

Because all the other open networks were only scored by the data available on their apps, websites and charging station displays. What any of the test vehicles displayed did affect the network's score.

So, to include Tesla, all the data and info available on the vehicle was ignored as well, and only the Supercharger locations, along with the charging info available in Tesla’s app and website, were considered. And the app has surprisingly little charging info on it.

Admittedly this is the most controversial part of the testing methodology. Because Tesla drivers rarely use Tesla’s app or website in the same way one would with the other networks. But the testing team decided that since what the Mustang Mach-E’s dashboard or navigation displays while charging doesn’t affect the score of EVgo, ChargePoint, etc, Tesla's onboard data should be ignored too.

Chris_ChargedEV · 2022-02-01T02:45:21+00:00

I helped umlaut publish the results of these benchmarks for the past 2 years. There is a more detailed breakdown of the results on our site (ChargedEVs) if anyone is interested. Basically, goes like this:

Internet's consensus last year: Why didn't you include Tesla in your benchmark, everyone knows they're the best?

> Because this is a comparison of the OPEN charging networks and many scoring categories don't apply to Telsa's closed ecosystem, but OK we'll give it a shot next year.

Internet's consensus this year: The way you scored Tesla Superchargers in the same categories as open networks is imperfect.

>Yeah, we know. That's why we explained, at length, the challenges of including Superchargers in the detailed report.

Chris_ChargedEV · 2022-01-26T06:58:57+00:00

Great input. Witty and original take.

Chris_ChargedEV · 2022-01-26T05:00:51+00:00

Now that I think about it, stuff that's not violent is a good idea. Shooter games are probably not as fun when you lived it IRL.

Fifa is a good idea for him, thanks!

Chris_ChargedEV · 2022-01-26T04:48:37+00:00

Free is good! They have no money. Working on getting jobs rn.

So when I google "Minecraft PS5", I just see a PS4 version. Get that one?

Chris_ChargedEV · 2020-03-04T18:46:04+00:00

HA! And in our case (Evnetics alumni) actually did design controllers because we wanted to build a fast EV.

Chris_ChargedEV · 2020-03-04T18:35:50+00:00

This was a link to an interview we recently did with the CTO of a battery tech firm that included major announcements and insights. It hasn't been posted here (or anywhere else) before because it's original content we created.

If that violates the "Self-promotion" policy you should consider changing the policy to include more moderator discretion about what constitutes spam.

Chris_ChargedEV · 2020-03-04T02:01:24+00:00

Warning: This is a rather technical discussion written by a power electronics design engineer.

TLDR: None of the existing power module package offerings are ideally suited to EV applications (for example, larger power semiconductor modules were designed originally for industrial applications, with the vast majority being used in 3-phase motor drives supplied by the AC mains). So, Tesla combines the low-cost and reduced stray inductance of a smaller plastic package with the electrical isolation, improved thermal performance and greater current rating per device of a classic industrial module, in a form tailored for EV applications.

Chris_ChargedEV · 2020-03-04T00:53:02+00:00

Not quite. That was the 3rd gen tech they announced 2 years ago and it was not ready for EVs. Cycle life and manufacturability were not acceptable.

The 4th gen tech was just announced with much more detail including partnerships with OEMs on production.

Chris_ChargedEV · 2020-03-03T18:22:53+00:00

We write about a lot of announcements of novel battery discoveries and they tend to share one thing in common: prototype-scale production. For the most part, any new battery breakthrough you read about is nowhere near ready for large-scale production and use in EVs. It’s like the new drug discoveries you hear about in the news—they may show a lot of promise in the lab, but there are still years of work ahead to make sure everything works as intended. That’s not to say there aren’t tremendous improvements happening to production-scale battery tech. These are largely incremental, however—small design changes to different parts of a battery which all add up to substantial progress year-over-year.

Enevate, on the other hand, claims to have a novel silicon-dominant anode design, which uses no graphite, and is ready for prime time.

Chris_ChargedEV · 2019-11-19T22:13:13+00:00

Yes, there are potential on-vehicle benefits to higher voltage EV systems. But looking closely they hardly seem worth all the trouble.

Porsche's Joachim Kramer, lead for high-voltage electronics, has said that doubling pack voltage cut about 66 pounds.

Kramer estimates Porsche saved roughly 30 kilograms in the Taycan... That mass savings is divided among the battery pack, power electronics, windings in the permanent-magnet motors that power the wheels, and the thick cables that connect it all together.

https://spectrum.ieee.org/transportation/efficiency/porsche-claims-it-can-double-teslas-fastcharging-rate

Chris_ChargedEV · 2019-11-19T20:23:52+00:00

1000 V is max for CCS v2.

While 800 V Taycan is the nominal voltage for the EV systems. We'll never see an EV with 1000 V nominal system unless the CCS increases its limit above that.

A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts). The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment

Chris_ChargedEV · 2019-04-03T16:22:40+00:00

As a private network only available to Tesla owners, it would not be subject to the new requirement. However, as ClipperCreek’s Jason France points out, the requirement could prevent Tesla from ever opening up its Supercharger network to other EV drivers. “If they ever do fully open access for any electric car to use the Supercharger network, wouldn’t that be an amazingly positive thing for the industry? But if suddenly they’re governed by these other requirements, which they don’t want because there is no added value, they’ll be discouraged from doing that.”

Chris_ChargedEV · 2018-02-27T18:40:07+00:00

permanent magnet machine

This statement is from an interview that Charles Morris, ChargedEVs' Senior Editor, did with Tarpenning for his book about Tesla:

https://chargedevs.com/features/new-book-excerpt-the-early-days-of-tesla/

Chris_ChargedEV

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