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When will we see an affordable electric car ?


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9 minutes ago, OftenWrong said:

The major heat would not be in the cable which has a fairly low voltage drop, but in the battery itself. That and a mongo sized transformer. A megawatt is approaching the power of a small nuclear reactor.

A better way imo would be to have pre-charged batteries ready to go. You pull into the battery station and swap out the battery. They they put it on a trickle charger for like two years...

Nuclear reactors are typically in the 200 MW - 2 GW range. And again, rectification off existing 480 V infrastructure means no need for big transformers. I agree that charging the battery at this rate causes major problems (heat among others) so that's why for now the problem remains with battery chemistry, rather than charging infrastructure. Once someone comes up with a commercially viable car battery that can be charged with 1-2 kA of current, someone will build the infrastructure to do so. 

Battery swaps are an interesting idea but I believe Tesla abandoned it for good reason. It's not like the battery is a single big cylindrical cell where you can just pop open a hatch, pop it out, and put in a new one. Rather, the battery is built into the structure and shape of the car so that it can optimize its weight distribution and handling. This is unavoidable since the battery comprises such a large portion of the overall mass of the car. Because every car will have different shaped batteries, you won't have a standard battery to swap. So swapping stations would need to stock hundreds of different models, which obviously isn't gonna happen. 

Edited by Bonam
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Just now, Bonam said:

Nuclear reactors are typically in the 200 MW - 1 GW range. And again, rectification off existing 480 V infrastructure means no need for big transformers.

Yes, as stated "small" nuclear reactor. But if you get more than a few of these charging stations going at one time, you'll need a power reactor for sure.

A megawatt is a megawatt, regardless of the voltage/current ratio.You brought the voltage down and the current up, so that you don't need to use high voltage insulation. But the power is still there. You still need to get rid of the heat, and the size of conductors in the transformer winding goes up accordingly. No matter how you slice it a 1 MW transformer cannot be made small. Power efficiency is such that if you deliver 1 MW to the load, and require 1 MW on the primary, the transformer dissipates 2 MW thermal.

Actual battery swap could be done by a machine. Standardization could solve problems you mentioned about different shapes. They don't need hundreds of different models, maybe just a few. Type AA battery? No, more like type ZZZZZZ.

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On 5/19/2017 at 6:14 PM, Bonam said:

A 1 MW charger (to charge a 100 kWh Tesla battery in 6 minutes) at 500 V means 2 kA of current. 2 kA of current can safely be carried by 8 parallel 0000 AWG conductors. That's a 1.5 inch diameter (+insulation) charging cable, which is certainly on the big side but not totally unreasonable (a 2 m long cable with this much copper would weigh ~20 kg which is a bit unwieldy, so you might up the diameter a bit and use aluminum conductors instead of copper, which would drop the weight to probably 10kg for a 2m long cable). Upping the voltage a bit would drop the current and make the charging cable more reasonable, and car batteries could be stacked with more cells in series to work at higher voltage, probably up to 1 kV or so.

Regardless, a solution can be developed where no megawatt-scale DC-DC converter is needed onboard the car. 

Realistically, I would predict that these charging systems will work off of rectified 480 VAC 3-phase power, so car batteries will have to work at that voltage (rectifying 3 phase 480V gives ~600 V I believe?). Using rectified 480 VAC power saves you having to have a big honking transformer at every gas/charging station and instead just a diode rectifier, which is much smaller and cheaper. 

Uh....you're kidding, right?  2000 amps @ 600V would require 2 runs of 1000 MCM - and you won't bend that.  You can't just bundle a bunch of single 0 gauge wire into one big cable and get the same rated amperage, as the cooling issue reduce the amperage considerably (thus why there is larger cable).

What you are missing is that this is for ONE charging station.  Go price out a 1MVA transformer, a 2000 amp rectifier, the switch gear, protection, etc. and you are looking at more than a hundred grand for ONE charging station!   Also, where are you going to GET the power that the SINGLE charging station needs, never mind the dozens in a typical service island and the thousands required for even a modest sized city?  Typical commercial buildings use no more than a couple hundred amps at 600VAC, you are now talking about industrial level stuff that is staggering expensive.  If you were to take ALL of the excess capacity of the service entrance to a large gas station, you would have maybe 0.1MW available - or one at a time, 60 minute charges.

I won't open the incredibly complex subject of rectifiers, peak voltage (that is useless in DC considerations) and effective voltage, but you are not going to carry that on board of a little car without it becoming a much larger and heavier car.

an earlier comment about no longer waiting for the lethargic gas pump to fill the car is laughable compared with reality for an electric charge in the real world.  Also, the comment about the rain:  you are going to have consumers handling 600V equipment IN THE RAIN!!!   AND, minimum wage pump jockies working around 25KV drops and transformers???    Geez, liability ambulance chasers will start order new Maybachs if that were to happen.

Let me put this into perspective:  I have been involved in converting natural gas pipeline pumps from combustion (old little jet engines) to electric.  This is about the same load a lineup of 1MW charging Teslas would use during busy times at a charging station.  20 years ago, that was over a $30MILLION bill for the transformer and rectifiers - and that assumes you already have a 230,000 volt substation, switch gear, protection, etc. already in place.   And you think we can just add THOUSANDS of such facilities to the grid and do what?  get "sunny days" to smile on a bunch of unicorn farts to power it?

Edited by cannuck
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12 minutes ago, cannuck said:

Uh....you're kidding, right?  2000 amps @ 600V would require 2 runs of 1000 MCM - and you won't bend that.  You can't just bundle a bunch of single 0 gauge wire into one big cable and get the same rated amperage, as the cooling issue reduce the amperage considerably (thus why there is larger cable).  BTW: the hardware exists - large draglines use pin and sleeve connectors up around that capacity.  I can assure you that Nice Nurse Nancy is not going to be able to heft one of those.  You are right inasmuch as cranking amperages on large diesel engines get into the several hundred range, and they do that with 0 guage wire, but very limited time before it melts

What you are missing is that this is for ONE charging station.  Go price out a 1MVA transformer, a 2000 amp rectifier, the switch gear, protection, etc. and you are looking at more than a couple hundred grand for ONE charging station!   Also, where are you going to GET the power that the SINGLE charging station needs, never mind the dozens in a typical service island and the thousands required for even a modest sized city?  Typical commercial buildings use no more than a couple hundred amps at 600VAC, you are now talking about industrial level stuff that is staggering expensive.  If you were to take ALL of the excess capacity of the service entrance to a large gas station, you would have maybe 0.1MW available - or one at a time, 60 minute charges.

I won't open the incredibly complex subject of rectifiers, peak voltage (that is useless in DC considerations) and effective voltage, but you are not going to carry that on board of a little car without it becoming a much larger and heavier car.

an earlier comment about no longer waiting for the lethargic gas pump to fill the car is laughable compared with reality for an electric charge in the real world.  Also, the comment about the rain:  you are going to have consumers handling 600V equipment IN THE RAIN!!!   AND, minimum wage pump jockies working around 25KV drops and transformers???    Geez, liability ambulance chasers will start order new Maybachs if that were to happen.

Let me put this into perspective:  I have been involved in converting natural gas pipeline pumps from combustion (old little jet engines) to electric.  This is about the same load a lineup of 1MW charging Teslas would use during busy times at a charging station.  20 years ago, that was over a $30MILLION bill for the transformer and rectifiers - and that assumes you already have a 230,000 volt substation, switch gear, protection, etc. already in place.   And you think we can just add THOUSANDS of such facilities to the grid and do what?  get "sunny days" to smile on a bunch of unicorn farts to power it?

 

Edited by cannuck
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  • 5 years later...

Still making the price is too high argument after seeing the prices of ANY new car these days? After the shortage and used cars listed at ridiculous prices?

Looking through the local private sales ads, it appears too many people believe people will pay those fake prices for rusted old hulks they see on TV and then drop $100K rebuilding them. Lots of ads for 30 yr old pickups that have been sitting on blocks in backyards and are listed over $10,000 these days.

You're going to shell out $40K+ for any new car. Lots of EV choices in that range now.

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  • 4 weeks later...

Maybe the question should be, when will we see an affordable electric car with comparable range to an ICE car and also can be recharged in the same amount of time it takes to fill up a gas tank?

Pickup trucks are extremely popular but some of the comparisons I've seen so far on Youtube show that range is a massive issue, especially when towing.

In this first video, there's a heartbreaking segment showing a child enduring abuse while mining for your electric car battery.

There are still a lot of hurdles to overcome with EV's and most politicians don't want to talk about them.

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  • 2 months later...
On 12/15/2022 at 10:30 AM, ironstone said:

Maybe the question should be, when will we see an affordable electric car with comparable range to an ICE car and also can be recharged in the same amount of time it takes to fill up a gas tank?

If available in my lifetime, would probably buy two.

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