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Fully Charged in Just 6 Minutes – Groundbreaking Technique Could Revolutionize EV Charging
(scitechdaily.com)
this post was submitted on 15 Sep 2023
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Alright, so let's assume a 100kWh battery like some tesla models. Now, someone made such a battery that can be charged in 6 minutes... how much power does it need?
100 kW•h / 6minutes = 100kW•h / 0.1h = 1000kW = 1MW
So, we need 1 MEGAWATT car chargers ... that's some power required there.
Possibly even more significant, those are some large cables and even larger contacts required. There's no way a 1MW disconnect is just a little plug you stick into your car.
In fact as an electrician I can't think of anything even near megawatt class that would be connected with a portable cord, or at a voltage that would be safe for consumers to handle.
Maybe someone in the mining industry or similar can chime in, but I currently run a pumping station that includes 3000HP motors (2.2MW). These are 4kV 3 phase units where each phase cable is as thick as your arm. All connections are bolted and taped to avoid corona discharge. Just dragging the cable to the car would be more than the average driver could handle.
I don't see a way to get these power levels into a car short of a standardized and semi-automated docking system. Or maybe go back to the idea of standard swappable batteries where the battery then is charged rapidly for the next customer.
The power lines in the cable are disconnected inside the charger by a contactor until communication with the car is confirmed established with a handshake, and then it connects power to the cable. If the communication with the car drops at any point, the contactor disconnects the power to the cable. It requires both effort and knowledge to bypass this design, it basically can't happen accidentally.
Also, the cables you mention are that large, because they're passively cooled, DC car chargers have watercooled cables so they can be much thinner without overheating. And at 4kV you're looking at significantly different insulation thickness as well, compared to the 400-800V that electric cars use.
Electric busses already have automated docking systems, the only problem I see is cost
https://assets.foleon.com/eu-central-1/de-uploads-7e3kk3/39195/17_syb21_content1.79205c469709.jpg
That's 4,350 amps @230vac. The service fuse for my entire home is 80 or 100amp (single phase domestic dwelling Australia). The main breaker is 63amp.
Fast charging uses up to 1000 V DC, and the current limits of conductors are typically set by the temperature it reaches when conduction losses heat them up. This can be (and is) offset by liquid cooling, allowing current installations to deliver up to 650 A (Tesla supercharger v3).
With improvements, it's not far off 1 MW.
DC fast charging typically runs at 400 volts, with some cars doing 800. They also do it with highly specialized equipment and service lines you'd never see in a residential setting.
When charging at home, you have all night. A 50A circuit will go 0-100 on most cars in that time, and if you look at what most people actually drive you can generally get by on much less.
how much amperage does utilities allow for residential use ? imagine charging ur car at 50 amp and decide to turn the heater on, only to trigger the breaker and cause the house to go dark lol. also home charging is costly as heck. 80kwh each night, wth ? u probably need 75m² of solar to generate electricity for 5 hours, generating 75kwh, enough to fully charge ur car for free, but also u need 7*11kwh powerpacks to accomodate all this energy. seems costly as hell. unless also ur job offers supercharger parking, which would be more suitable
A fair question. Depends on the house. 100-200 is common, depending on the age of the house. 100 or less if your house predates central air conditioning, and 150-200 is far more common in the last few decades. Most people charge overnight, and they're not using much else. If you truly have a smaller connection, even 20A @240V is surprisingly useful. Or hell, a normal outlet.
That may be your battery's capacity, but that's not necessarily your draw. How big is your gas tank? Do you give it ~15 gallons each day? My car gets about 3.5 miles per kWh. If I drive it 70 miles, that's 20 kWH and then the car stops charging. And I pay about $2.50 for it. What would gas cost?
Solar direct to car is actually a terrible idea. Just hook something up to the grid if you want solar, but it's pretty cheap without. You're overthinking it, probably because your 80 kWH per day number is so out of whack.
Again, no. Well, it's cool if you can get it but it's really not needed because home electricity is generally way cheaper than gasoline.
yea, fast charging is usually achieved using DC.
u wouldnt plug in and plug out the thing live in a charger, no ? the charging station should detect when the car is plugged then activates some form of disconnect or something, to allow a 1Mw power to flow lol ? also 1Mw is far fetched, and the 6 min charging time is absurd. 12 min at 500 Kw speed would be more plausible
thats assuming 100% efficiency. which is impossible
I'm happy with 69 efficiency. 🙃
True, so I guess 1MW won't even be enough
Typically you’re getting about 97-99% efficiency at a supercharger in ideal conditions (not running heat, around 70F outside, etc).
most EV cars are more like 60kwh though.
The person above you said Tesla. Most newer Tesla models are 75 kWh-120kWh.
incorrect. most are 56kwh
Oh damn, I didn’t realize Tesla started making the standard range again. When I got my LR RWD in 2018, they were not selling the SR anymore. However, their Model Y starts at 75kWh, and their Model S and X are only 100kWh now.
yea, 100kwh is too few. 170kwh would be ideal (for a model 3). The models S and X should have had a 250kwh pack, to support that needlessly fast acceleration.
I think 100kWh is ideal for a Model 3. I drove my LR RWD across the US (MS to CA to WA) and didn’t really have an issue. It was only bad when it got really cold outside, so having an extra 30% would cover that. It would have about 400 miles of range on a full charge, and 20 mins at a super charger would get you from 10% to 80%, so 300 miles, or another 4 hours of driving.
600Km in a single charge ? 450 km mileage in 20 minutes ? i am surprised. although i would feel more safe if a 20min stop adds another 150km (yea, 30% increase in battery size would be cool) (but how about running ac, towing stuff ? that could really decrease the efficiency) nonetheless, home charging is costly if u plan on adding 70kwh ever night to ur utility bill. so as a commuter, i should predict a 20 min stop to supercharge cheaply before getting home. then tomorrow, another stop mid day.. Superchargers will be congested if this isn't adressed, u hav a factor of 20x to tackle: people would fuel up with gasoline in a 1 minute or so instead, if everyone where to have EVs
At home, most people are only charging about 10-20% every night. For 100kWh, let’s say 20kWh, which is 60 miles. Most people at home will be using a 240v 50A outlet, which outputs 12kW. You’d be done charging in about 2 hours at 95% efficiency for 21kWh from the outlet (heat loss and whatnot does take a significant portion of charging). At my place with $0.13/kWh, that would just be a measly $2.75 at 95% efficiency. Wayyyy cheaper than gas. That’s around the same as a car with 85mpg at $4/gal gas. Most cars are around 30mpg on a good day.
a Mk6 diesel would do 60mpg..but again, prices would also influence this. Yea well, as long as electricity stays cheap, and cost of the supercharger stays also low, then that would be a viable choice (i wonder how much 1kwh costs at a supercharger?). Also, when a company judges a product is too good, it would pull a premium from its ass just to drain money from its customers, especially, in the case of OTA connected cars like Teslas, anything could happen. Lithium mining becoming too expensive: u only get to use 75kwh only of ur battery (idk, similar non sense.. remains to be seen, depends on a company goodwill..like when they retracted free supercharging from Legacy S and X owners, straight rug pull) . Also again, cheap electricity would imply congested superchargers in the future :/
Supercharger costs are very different across the board, but never as cheap as charging at home. Looking at my charging at superchargers for the whole year in the Pacific Northwest (all in WA, OR, and Canada), it was $0.35/kWh on average. It can get up to $0.50/kWh when using it during peak hours, which is typically 10am-7pm.
supercharging needs to become cheap to boost EV sales. say if an average tesla driver needs to recharge about 100 kwh per day, 1kwh could be produced by 5 m² of solar in 1 hour (average solar day lasts about 6 hours), then each car requires about 80 m² of solar panel area, to cover the daily needs of a single car. imagine each year 500k tesla cars join the fleet, so each year 40 km² of solar is required to feed Teslas with pure renewable energy: alot of estate is required to accomodate the electrical needs of such cars: nuclear and fossil are out of the question, so might as well start looking into fusion to achieve net 0 emission energy. Elon said before Tesla was a battery company, i think he should reconsider this and try to tackle the energy problem instead, might as well become an electrical utility company. if the price 0.13$/kwh could be democrarized among superchargers that already would be no small feat (90mpg can already be addictive haha, but people also made due with 30mpg @4$/gal using 15k$ cars) in ur case u could fully charge at home since it is cheaper, unlike how i thought about it at first)
95% of driving is within 60 miles of the house. Supercharging isn’t needed to sell EVs. Cheaper EVSs are needed to sell EVs.
diesel is literally destroying the planet with both particulate and CO2. I'd factor that into the costs. I'd rather pay 200% more for electricity if it means we can sleep at night knowing I'm not poisoning the environment to drive around everyday. You can literally use solar panels to charge your car and batteries can be 99% efficiently recycled. yes tyre dust is still a huge problem we need to fix. but petrol and diesel need to die asap and not be considered as viable options.
a car releases alot of fine particles, i agree, even brake pads release particles. fossil is not only polluting but it is also finite as a ressource, and also is uranium. air travel is addicted to fossil and that needs to stop: electric powered trains could make for a good alternative, but u would need long stretches of land to produce enough energy to satisfy these needs through solar, while waiting for fusion tech to be unlocked
why not have a car with 2*300kw charging plugs, and with 200kwh battery (u would get 160kwh in 36min, which achieves a solid mileage, at an efficiency of 150wh/km). Tesla Semis already charge their 800kwh pack in 3 hours (i assume its done using a 300 kw plug ? ), still not sure
Tesla semi is meant to be able to charge at 1mw, which makes sense considering the size of the battery, bigger battery means more cells and more space for cooling. The truck is also meant to support 1mw with the new v4 chargers. So if you believe Tesla (which is hard because of Musk), it is coming.
Charging that rapidly is only possible for some but not all 100% of the battery as you have to slow down as you approach 100%. 350kw chargers slow down around 80% (I've gone as high as 85% before I've seen the slow down). This happens at all charging speeds to protect the battery, even 7kw chargers slow down for the last couple of percent.
However charging to 100% of the time on ultra rapid chargers is monumentally dumb as it's considerably more expensive per kWh than slow chargers, slower for that last 20%, blocks chargers for longer, and isn't good for the long term health of the battery. It is as quick to charge twice to 80% than it is once to 100% on the same charger for 60 to 70% more range from charging twice. This is true because you avoid slowing down at the end of the charge.
You're speaking with current lithium battery technology in mind. Supposedly, scientists in the article figured out a new technology that can be charged in 6 minutes. No word on whether it's still necessary to slow down at the end, or charging efficiency. Time will tell I guess
It's highly unlikely that they solve what is essentially a heat distribution problem with new battery materials. If you stick a huge number of cells in a giant cooling system then you can charge even lithium considerably faster than we do now for all of the 100%.
We are limited by the space, how good the battery pre condition charging is,maintenance schedule of the car and charging point.
My car has a separate fluid cooling system for ultra rapid charging that has its own maintenance schedule, if this system was bigger and didn't have to go a minimum of 12 months between changes then it could be charged for longer at higher speeds.
If my car had a bigger battery with more cells in a suitable arrangement then again I could charge faster for longer as the charge is spread out across the battery. However eventually you'll hit the point that you are only charging a few of the cells as the rest are full and you have to slow down or the battery will get too hot.
I just don't see them completely solving the heat problem, just improving the current percentages.