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We're Charging Our Cars Wrong

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Re: We're Charging Our Cars Wrong

#181

Post by SkyPuncher »

Elixir6419 wrote: post #10

It would be nice if instead of the fast charging problem the focus would be shifted to standardized battery packs, that can be field replaced. I don't really want to own 50-100kwh battery. I just want to use the charge in it and happy to pay for that.

I absolutely do not want that unless there are guarantees around the condition of the batteries.

I can't imagine much worse than being on a road trip and quick swapping to a new battery that you discover, after driving away, has significantly degraded performance and range.

Re: We're Charging Our Cars Wrong

#182

Post by coryrc »

loeg wrote: post #99
coryrc wrote: post #88

Earlier quoted context omitted.

It's 7 mph of charging. The average car is driving 60 minutes per day, and if there are chargers everywhere that's 161 miles per day of charge if it's plugged in when not driven. That covers everything the existing system doesn't already.

The 7mph claim is inflated. The rare EV gets more than 5 mi/kWh in any situation, especially highway driving, and your L1 charging is getting you roughly 1 kWh/hr. > The average car is driving 60 minutes per day This is a sleight of hand. Non-average situations arise all the time. Your proposal is ridiculously burdensome and not especially helpful.

> Non-average situations arise all the time.

Of course. We already have blanketed the country with level 3 charging. You can reach 99% of the country solely using Tesla Superchargers. The non-average problem is solved.

What we need to solve is the "can renters buy EVs knowing they will always have reasonably-priced place to charge" problem.

Re: We're Charging Our Cars Wrong

#183

Post by Dylan16807 »

LooseMarmoset wrote: post #180
Dylan16807 wrote: post #155

Earlier quoted context omitted.

Has it been spent? Allocation is not spending.

allocated == money handed out in accounting rules, it's spent money. the notes say that 61 ports have been built from that allocated money. like I said, I would love to see the cost breakdown. is all that allocated money spent? are some projects still being constructed? three years seems like a long time to get 61 ports when you allocated $2B.

I'm more concerned with whether the entities that were handed the money have themselves spent it yet.

Re: We're Charging Our Cars Wrong

#184

Post by cyberax »

jmb99 wrote: post #50
nick3443 wrote: post #25

Earlier quoted context omitted.

I would guess it will jump to a grounded conductor inside the charging cabinet or the grounded case of the cabinet itself before it goes to the car that is sitting on rubber tires

Lightning can strike cars directly, and when it does, the couple inches of air and rubber between the car and the ground mean nothing (the tires sometimes explode, which looks neat when caught on video, if nothing else). Remember, the lightning travelled for thousands of metres through the air before reaching the car - another 4” of “insulator” isn’t going to stop it. Now, if lightning were to strike the charging cab…

There was a cases of a Tesla getting struck by lightning while supercharging. It killed the electronics in the car and the charger, but otherwise nothing particular happened.

The lightning discharge won't create a potential difference across the battery terminals, it'll flow around the battery through the car's body into the ground.

Re: We're Charging Our Cars Wrong

#185

Post by cyberax »

brabel wrote: post #112
cyberax wrote: post #64

Earlier quoted context omitted.

Imagine a catastrophic fault: a dude in another car drives into your car, and a conductor in the car breaks off and energizes the car body. The current now goes through the car body into the ground, and also through the grounding wire back to the charger (EVSE). It's a phase-to-ground short. The charger tries to interrupt the flow, but the short circuit fries the power electrics in the buck converter (MOSFET/IGBTs ca…

Imagine a catastrophic fault: a dude in another car drives into your car at the petrol pump. The petrol pump starts dropping huge amounts of petrol on the ground. Part of the car wreck falls back on the ground and ignites a fire, causing the whole station to blow up, killing everyone within 100 meters. Clearly, we cannot allow petrol stations to exist.

Modern petrol stations are designed with this very scenario in mind. The above-ground structure can burn down, but the underground gas tank will still be fine.

And more to the point, right now with galvanic isolation this scenario fails safe. The current won't go through the ground. In fact, you can peel away the insulation from the charger cable and touch one conductor while a fast DC charging session is in progress. You will be fine, as long as you don't touch the second conductor at the same time.

Re: We're Charging Our Cars Wrong

#186

Post by Huppie »

LooseMarmoset wrote: post #180
Dylan16807 wrote: post #155

Earlier quoted context omitted.

Has it been spent? Allocation is not spending.

allocated == money handed out in accounting rules, it's spent money. the notes say that 61 ports have been built from that allocated money. like I said, I would love to see the cost breakdown. is all that allocated money spent? are some projects still being constructed? three years seems like a long time to get 61 ports when you allocated $2B.

I'll be honest and tell you I didn't look into the specifics of this project.

My guess would be that the money is also allocated for an X amount of sites / charging ports still in progress. Or do they only allocate the money after the site is fully operational?

If that's the case, I think saying '2B spent for 61 ports' is disingenuous at best.

Re: We're Charging Our Cars Wrong

#187

Post by Huppie »

LooseMarmoset wrote: post #85
jdminhbg wrote: post #43

Earlier quoted context omitted.

> Over the course of the Biden-Harris Administration, the number of publicly available EV chargers more than doubled. With approximately 1,000 new public chargers being added each week, there are over 200,000 publicly available charging ports. The trick being played here is counting all charging stations in the US and pretending they're part of the IRA's funding.

Yes, that is a neat trick. > As of July 2024, eight states had opened their first NEVI-funded stations, totaling 61 ports, and powered thousands of charging sessions. As of FY 2024, $2.385 billion had been allocated from the funding. For 61 ports across 4 (four) charging locations. $39M PER PORT. This, per NEVI's own numbers: https://driveelectric.gov/files/nevi-annual-report-2023-2024... I would sure like to see a b…

You don't think a (probably significant) portion of that money is allocated to sites that were 'in progress' on July 2024?

From what I can tell from the newsletter I get from a big European charging infrastructure provider the lead time of a new charging location tends to be 1 - 2 years depending on the specific location.

While I do agree these numbers are disingenuous, looking at politics I definitely see the next administration counting the chargers that will come up past January 2025 to their win list. Oh well, I guess that's politics.

Re: We're Charging Our Cars Wrong

#188

Post by theshrike79 »

monero-xmr wrote: post #172
theshrike79 wrote: post #166

Earlier quoted context omitted.

There are no gas stations on my route. I'd need to specifically drive to one. And the one closest to my commute has a massive queue _every_ time. I just rather drive home, plug in and the battery will be at 80-100% next morning, depending on how much I drove that day.

You must be the rare person with no gas stations near your entire commute!

That's what I get for living in a small town :)

The gas stations are on the main road that passes through the town, I don't use it for my commute, I literally have to go out of my way to hit a gas station - which is owned by my uncle (small town, I know)

Re: We're Charging Our Cars Wrong

#189

Post by theshrike79 »

nothercastle wrote: post #173
theshrike79 wrote: post #164

Earlier quoted context omitted.

Electric engines are 90-95 efficient in converting power to motion. Even the very best experimental gasoline engines in Toyota's labs are around 30-35% efficient. Even if all gasoline and diesel was used in massive generator units to produce electricity, EVs would still be better for the environment and the total gasoline/diesel usage would go down.

But the power plant has only slightly higher efficiency off the fossil fuels it burns. So you need to use the ev to store excess grid solar generated during the day to truly get an advantage

Look up "district heating". The power plant can capture the waste heat and use it for something useful.

Your car just radiates it wherever, benefiting no-one (except during winter)

Re: We're Charging Our Cars Wrong

#190

Post by pbronez »

rcxdude wrote: post #163
raldi wrote: post #91

Buried deep in the article, what the clickbait headline alludes to: Car chargers are too complicated and expensive. We can make them simpler and cheaper while keeping them safe, which would let us build many more charging stations.

I must say I'm a little confused by their proposal: yes, the later stages of the power conversion in the charger provide the galvanic isolation, but they also provide a more essential role of voltage conversion and current regulation. Connecting a battery directly to a grid-connected rectifier is likely to get melty and or explodey pretty quick, as huge amounts of current will flow in either direction to try to equal…

They propose to address this with a buck regulator:

> [If] we are to get rid of galvanic isolation [there's still a ] need to prevent mismatches between the utility’s AC line voltage and that of the EV battery.

> The solution to this problem is a device called a buck regulator (or buck converter). A buck regulator is similar, functionally, to a step-down transformer, except that it handles DC current rather than AC. In the event that the utility’s AC voltage exceeds the battery voltage, the buck regulator operates like a transformer and steps it down. In comparison with an isolation link of the same power rating, a buck regulator would cost less than 10 percent and the power loss would be less than 20 percent.

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