Electric car game changer
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Haven’t checked your arithmetic but sure, it takes a lot of energy to move a car a couple hundred miles and the delivery of that kind of energy in a short time is an immense amount of power. Presumably this would be delivered at a station built for purpose.
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1500 A is going to create some real challenges. Stuff is liable to get very, very hot at that current which is both dangerous and inefficient.
I have a vague suspicion that the battery charging system may have been designed by a marketing person rather than an engineer.
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That’s really naive. There are dozens of startups with top talent chasing battery technology. The successful ones will rival the oil majors in market cap. We are decades past the ‘two guys and a dog’ approach.
"You never know what worse luck your bad luck has saved you from."
-Cormac McCarthy -
That’s really naive. There are dozens of startups with top talent chasing battery technology. The successful ones will rival the oil majors in market cap. We are decades past the ‘two guys and a dog’ approach.
@jon-nyc said in Electric car game changer:
That’s really naive. There are dozens of startups with top talent chasing battery technology. The successful ones will rival the oil majors in market cap. We are decades past the ‘two guys and a dog’ approach.
1500A is 1500A. There's a reason over-head power cables are at 700 kV, and it's not for the purposes of safety.
Like I said, I could easily be missing something, but 1500A just doesn't sound right.
And I've worked with a lot of companies where marketing people design stuff, then hand it over to the engineers to "sort out the final details".
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That’s really naive. There are dozens of startups with top talent chasing battery technology. The successful ones will rival the oil majors in market cap. We are decades past the ‘two guys and a dog’ approach.
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It seems to me like a lot is going to need to change for this to be achievable.
Google indicates a car battery capacity is roughly 50kWh, so to charge one in 5 minutes is going to need a charger capable of delivering 50 x 12 = 600 kW. For a battery voltage of 400V (again from Google), this correlates to 1500 Amps, which is a stupidly high current.
Or am I missing something obvious?
@doctor-phibes said in Electric car game changer:
It seems to me like a lot is going to need to change for this to be achievable.
Google indicates a car battery capacity is roughly 50kWh, so to charge one in 5 minutes is going to need a charger capable of delivering 50 x 12 = 600 kW. For a battery voltage of 400V (again from Google), this correlates to 1500 Amps, which is a stupidly high current.
Or am I missing something obvious?
From the article...
"StoreDot is aiming to deliver 100 miles of charge to a car battery in five minutes in 2025. "
100 miles in 5 minutes sounds like 1/3 of the total capacity of the batteries.
So maybe 500 amps. Not that much of a stretch.
7 years ago I was charging 4 x 5,000 mAH Lithium Polymer batteries to full capacity in 5 minutes.
3D RC helicopters routinely pull 200 amps while flying.
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Hey @Doctor-Phibes, how fat a piece of copper cable would be needed to transfer 1500 Amps, for, say 1 meter of distance between the charging station and the car?
I tried to use an online wire gauge calculator to figure out how the wire gauge needed to transfer 1500 Amps and the calculator says that number is "out of range."
I try to imagine a bundle of 10x the sort of power grid cable that feeds 200 Amps to a typical residence and it does not seem that bad, maybe a cable bundle that's 10cm across? :man-shrugging:
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Not sure about specifics - all the tables I found didn't go as high as 1500A. Typically, in the work I do the maximum prospective short circuit current of a mains installation is considered to be about 1500A - i.e. that's the most you'll get out of it under some horrendous fault, in a transient condition. And we're going to be doing that in normal operation, under steady state conditions?
Hey, at least the safety folks will have job security.
It's always felt to me that a hundred years from now they'll be laughing at our ridiculous intention to swap out gasoline for batteries in the hope of reducing pollution.
Hydrogen's the way to go.
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.... says the guy who regularly broke the laws of physics.
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Enables <15 minute fast charge (0 to 80%) by eliminating lithium diffusion bottleneck in anode host material.
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Enables <15 minute fast charge (0 to 80%) by eliminating lithium diffusion bottleneck in anode host material.
@copper said in Electric car game changer:
Enables <15 minute fast charge (0 to 80%) by eliminating lithium diffusion bottleneck in anode host material.
Since that's 3 times the charge time of the other one, this is already completely obsolete, and it hasn't even been released!
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It seems to me like a lot is going to need to change for this to be achievable.
Google indicates a car battery capacity is roughly 50kWh, so to charge one in 5 minutes is going to need a charger capable of delivering 50 x 12 = 600 kW. For a battery voltage of 400V (again from Google), this correlates to 1500 Amps, which is a stupidly high current.
Or am I missing something obvious?
@doctor-phibes said in Electric car game changer:
It seems to me like a lot is going to need to change for this to be achievable.
Google indicates a car battery capacity is roughly 50kWh, so to charge one in 5 minutes is going to need a charger capable of delivering 50 x 12 = 600 kW. For a battery voltage of 400V (again from Google), this correlates to 1500 Amps, which is a stupidly high current.
Or am I missing something obvious?
That's what I thought as well.
The most powerful charging stations over here charge with 200KW. They are extremely expensive and require enormous cooled cables.
Also, the influence on the stability of the overall power grid, bot locally and nationally, would presumably be quite significant if thousands of cars would suddenly begin charging at 600KW.
Finally, I wonder what a realistic cost for a kwh of energy would be from one of those super duper charging stations. From what I read, a fair non-subsidized price for a kwh at a high power charging station would be >1$ per kwh, so we can all guess how much that would be with a 600KW charging station. It is in any case orders of magnitude more expensive than gasoline.
I also wonder what the influence of the super-fast charging on the life time of the battery is. Usually, batteries are not happy about such things.
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Dead end technology. You think oil isn’t renewable? Compare that to Lithium! We’re digging a hole faster and faster.
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A related story:
https://techxplore.com/news/2021-01-inexpensive-battery-rapidly-electric-vehicles.html
Range anxiety, the fear of running out of power before being able to recharge an electric vehicle, may be a thing of the past, according to a team of Penn State engineers who are looking at lithium iron phosphate batteries that have a range of 250 miles with the ability to charge in 10 minutes.
"We developed a pretty clever battery for mass-market electric vehicles with cost parity with combustion engine vehicles," said Chao-Yang Wang, William E. Diefenderfer Chair of mechanical engineering, professor of chemical engineering and professor of materials science and engineering, and director of the Electrochemical Engine Center at Penn State. "There is no more range anxiety and this battery is affordable."
The researchers also say that the battery should be good for 2 million miles in its lifetime.
They report today in Nature Energy that the key to long-life and rapid recharging is the battery's ability to quickly heat up to 140 degrees Fahrenheit, for charge and discharge, and then cool down when the battery is not working.
"The very fast charge allows us to downsize the battery without incurring range anxiety," said Wang.
The battery uses a self-heating approach previously developed in Wang's center. The self-heating battery uses a thin nickel foil with one end attached to the negative terminal and the other extending outside the cell to create a third terminal. Once electrons flow it rapidly heats up the nickel foil through resistance heating and warm the inside of the battery. Once the battery's internal temperature is 140 degrees F, the switch opens and the battery is ready for rapid charge or discharge.
Wang's team modeled this battery using existing technologies and innovative approaches. They suggest that using this self-heating method, they can use low-cost materials for the battery's cathode and anode and a safe, low-voltage electrolyte. The cathode is thermally stable, lithium iron phosphate, which does not contain any of the expensive and critical materials like cobalt. The anode is made of very large particle graphite, a safe, light and inexpensive material.
Because of the self-heating, the researchers said they do not have to worry about uneven deposition of lithium on the anode, which can cause lithium spikes that are dangerous.
"This battery has reduced weight, volume and cost," said Wang. "I am very happy that we finally found a battery that will benefit the mainstream consumer mass market."
According to Wang, these smaller batteries can produce a large amount of power upon heating—40 kilowatt hours and 300 kilowatts of power. An electric vehicle with this battery could go from zero to 60 miles per hour in 3 seconds and would drive like a Porsche, he said.
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"Now look here, you Baltic gas passer... " - Mik, 6/14/08
The saying, "Lite is just one damn thing after another," is a gross understatement. The damn things overlap.
