The Tesla Model D is unveiled

@starman1 - I agree, batteries are heavy and expensive. I make that exact point when I’ve stated that standard hybrid/gasoline cars are a better solution for most people (and the country) than EVs. But that’s not the comparison here. FCVs are expensive, unproven, and require huge expenditures for infrastructure. So I’d rather the country spend its limited $$ on solutions that result in equal or better CO2 reductions at far lower cost.

Do you have a solution to propose?

Because if we agree that gasoline is eventually going away, and that battery power can’t be made practical… what are we left with?

@starman1

There likely won’t be any major breakthrough in battery physics that suddenly allows for smaller batteries with high energy density to be produced.

Welll…

Doesn’t change the size of the batteries much, but if you could charge a Model S to 70% in 5 minutes you’d get another 200 miles out of it. Charge it while stopping for lunch and you’d have a full charge before you finished your pie.

That would easily put it on solid footing with gas cars for road trips, especially if the increased battery lifespan is taken into account - with the already reduced routine maintenance of electric cars (no oil changes, no tranny fluid changes, no spark plugs/wires/cap/rotor/coilpacks/whatever) if you got 20 years out of the battery it would be a very clear winner over gasoline powered cars from an economic standpoint, especially once the more normally-priced Model 3 (and hopefully its competitors, assuming the big guys decide to get serious about electric for a change) comes out.

I don’t agree with either gasoline supplies will be a problem in the next 20 years, given the increases in fuel economy and drop in gasoline consumption, or batteries ‘can’t be made practical’, the advances will be slow, but give the amount of gasoline we have, and the reduction in consumption, there is time. And if a compressed gas vehicle is worth pursuing, it’d be CNG, with a ready infrastructure, cheap price, and better emissions than gasoline.

Hydrogen is being considered because it can be refueled in a few minutes while batteries cannot. Nor will they likely ever be rechargeable in 5 minutes.

For example, take a 60,000 Watt-hour battery discharged to 20% over 250 miles. The car used 48,000 watts over 5 hours at 50 mph. To charge it in 5 minutes takes over 2.88 Million watts applied to the battery if we assuem 100% charging efficiency. With industrial size 440 volt 3-phase power applied, this is over 6500 amps. THAT is a power surge!

Hydrogen can be created cleanly from electricity and water and it can be done with solar cells during the day. All that equipment is expensive. That is why hydrogen is made primarily from natural gas. Range is similar to the better electrics. Because of refueling it is a more practical solution for cars than batteries.

Just because we are 20 or more years away from gasoline supplies being a problem, doesn’t mean we can take a “We’ll cross that bridge when we come to it” mentality. I, for one, am hoping to be alive and well enough to drive more than 20 years from now.

And I expect 20 years of EV advances to fit right in to the timeline, in addition to CNG.

I’d be willing to place a bet with you on whether battery power can be made practical, but we’d have to wait 20 years for the payoff!

I get 48 kWh over 5 min or 0.0833 hr is 48/0.0833 = 576 kW.

At 440 V, 3-phase, that’s 576,000 W / [(440 V)(1.732)] = 756 amps. (Assumes power factor = 1)

These quick-charge stations would probably bring in power at 4000 V.

I remember a 3000 hp (2.2 MW), 4000 V, 3-phase electric motor driving a vapor-recompression evaporator at a pulp mill. It shook the whole building when they lit that sucker off.

Thanks, @insightful, late night brain fade math error! 576 kW sounds more reasonable The quick charge stations can’t bring in power at 4000 volts, unless the car itself has an AC/DC convertor that can accept 4000 volts AC at the plug and step it down to the 400 volts DC or so the battery requires. Then the battery still needs to be able to accept the 800 + charging amps all at once.

Yeah, I’ll be dead before there’s a battery that can charge at that rate and last more than a year.

"Do you have a solution to propose?

Because if we agree that gasoline is eventually going away, and that battery power can’t be made practical… what are we left with?"

Well…third rail epitomizes “proven technology.” We KNOW that it works for trains…why not autos? Seems cheaper and better than spending on unproven tech that may or may not prove feasible.


Electrify the cities and interstates first, and size batteries for travel between grids.

It will be a while before petro power cars give way to totally electric. In my post earlier referral, there is even testing of gasoline fuel cells as a way to extend the range of electric cars. Together with a smaller battery to power the car, the fuel cell would not have to be cycled on and off as much, which is a drawback for them. It’s a match made in heaven and one that could be and is; ( George Bush advocated for it) supported by the petroleum industry. Just getting an electric drive motor in there would be a step forward…

In the real world. The electric motor replaces the transmission and the fuel cell/battery, what ever combination you decide, replaces the ICE/ fuel tank. If that can be done, electric cars are off and running and gasoline only power cars, not trucks, start dwindling in number.

Electrifying roadways doesn’t seem practical to me. Power rails on the roadway are too dangerous. Overhead lines might work if the cars sit high, but even then, the boom would have to be quite long to connect to both cars and trucks. How would you pass? I just can’t see a Miata with a huge boom connecting to the overhead power line.

@jtsanders‌
As you can see, there is research to show that electricity can be transmitted short distances . This maybe sufficient to imbed “electricity” in the road bed and allow cars with appropriate “coils” to receive the electricity. So, it isn’t a matter of having a boom and wires. There are electric devices that can be recharged now without a direct connection…like my electric tooth brush. And, if I touch it (the base) with my finger, I don’t get electrocuted because my finger doesn’t contain the compatible elements to create a circuit.

that would take a lot of road work dag…

Keep thinking Dag,we need people that can think outside the box-Kevin

@‌kmccune
That’s something my wife would say…but then she adds, “let me lock you in your room first”. Your “bright ideas” have broken too many things.

Inductive charging is something the forklift industry has been investigating for quite a while to eliminate or minimize battery changes. There is lots of losses with distance so the coil needs to drop down to meet the floor. There is a New Zealand company that has some interesting technology to inprove the energy transfer. So far, it is too big a tear-up for their small scale (500,000 sf) facilities with too little benefit. I can’t see this working on a car-scale installation. City buses look promising, though.

I agree with @wesw. The cost of infrastructure is quite high. Thanks for the link, @dagosa. It may have some future. But not any time soon, I think.