Author Topic: [Rant] Electric cars, in particular Nissan Leaf  (Read 59959 times)

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Offline free_electron

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #75 on: September 29, 2013, 07:34:35 pm »
They have the luxury to outsource the battery factory. Nissan doesn't.
Also, 1/3-1/2 of the cost of the car is the battery. If they make it twice the size, it will be ridiculously expensive.

And leasing a battery is like having an insurance on the most expensive part in your car. Battery cells do brake, and I dont want to drive my car around praying for

1) Tesla builds the battery right here in Fremont, just like 90% of the car. Even the motor is built in house. No importing cheap crap from china. 90% of the car component is made in silicon valley. They stamp their own body panels from rolls of aluminum. They assemble their own circuit boards as well ( yes they have their own pick and place machines !) Find me a car maker that can say that ... the only parts they buy is the glass, the leather for the seats, the steering wheel and levers and the speakers and rims and tires. Everything else is done in the plant in Fremont. They even make their own plastic parts. They got injection molders, stamping presses (They own the largest stamping press in the US ).

Making a car in one of the most expensive area's of the world (in terms of labor cost, factory cost, production cost)... and still making a hefty profit.

The individual cells are made by Panasonic with Samsung and LG now have gotten a licence to make the cells (the cell technology,read chemistry and internal cell construction)  is Tesla owned technology. It is a modified li-ion chemistry with a different electrode construction but does fit the standard laptop cell form factor 18650 or whatever it is called.) They added an intumescent to make the cell self-extinguishing and a small circuit board that can eliminate the cell from the loop should it fail or degrade.

2) yes the batter is 1/3 the cost of the leaf. Which costs 38000$. Double that battery pack. It'll add 10000 but it will make the range acceptable !

3) Tesla gives you 8 years no questions asked warranty on the battery AND the drive train (motor+reduction gearbox). The Tesla battery pack can be repaired as it is constructed if individual cell clusters. The nissan ? probably a whole swap is needed...
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Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #76 on: September 29, 2013, 07:35:59 pm »
Perhaps the impressive electric car, can't remember what it is called, is a sportscar simply because it is the only body style with lots of room to hide lots of batteries. Remember seeing the engine in an E type once, that sort of thing.

If you would ignore safety/crashworthiness regulations, your assumption would make sense. You don't really want to have a huge lithium battery running amok in case of a crash...

The reason why sports cars: Guaranteed attention (nobody really dreams about a VW Golf) and because sports cars will never be discussed/examined as serious everyday general-purpose vehicles.
 

Offline free_electron

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #77 on: September 29, 2013, 07:52:34 pm »
Perhaps the secret is in the words 'don't fit a bigger battery' in where does it go?

go take a look at how Tesla did it. You are sitting on it... it is a pancake , 3 inches thick the entire width of the car and fits between the front and rear axle. there is so  much room leftover you can use the place under the bonnet as an additional trunk.
Not in the leaf. They crammed that compartment full of batteries because they did not want to re-engineer the structure of the car from the ground up.
Like i said 'incremental change' is all what they seem to know. The traditional car makers seem to be unwilling or incapable of re-engineering from zero..
Take out petrol engine, drop in battery pack and electric motor.  That is all they did. This has been tried over and over and it doesn't quite work right.

Use the available room under the car ! you don't have an exhaust system , no drive shaft , no fuel lines, no brake lines and none of the other crap you have in a regular car. If you slap the engine in the rear between the wheels, and if you make the battery part of the cars frame it hides itself ! This is not what they did on the leaf. That entire space is left unused... not smart...

&elgonzo . crash and safety ? The Tesla is the safest car ever tested. It outperforms any car in any test. It even outperforms all cars in different categories in all tests. They couldn't make it roll for the roll test , they had to artificially flip it and when they tried the test to see what would make the roof cave in the Tesla destroyed the testing machine... Most cars collapse the roof at 2 to 3 times the weight of the car. They hit 4 times the weight of the Tesla (which is , at 2 tonnes, more than your average car) at which point the test machine broke... the roof doesn't move. Turns out it is not welded on , but bolted on using the same kind of bolts used to put wings on an aircraft ... the struts holding the roof are part of the main car structure and give it its rigidity.

The Tesla only looks like a car. It is in every aspect , when it comes how it is constructed, totally different from what anyone else does.
Why can't other car makers do that ? are they so set in their way of work they can't innovate anymore ?
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Offline reagle

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #78 on: September 29, 2013, 08:08:26 pm »
I've visited a local plug in day as well, and I drive hybrid so here are my two cents
First impression- look at all these cars that did not exist a few years ago! We had Leafs, Volta, Teslas, Rav 4EV, Honda Fit EV,  Zero bikes and tiny things like MiEV. And they were represented by their owners, not sales droids. Huge difference. You get to see real people who are happy with their cars and can tell you their real life experience. I am not at all surprised that a given sales droid from a stealership was clueless. This is why Tesla does not want their cars sold by dealers.

As far as the best car for your usage- with such a commute Leaf is not a good idea. A Tesla (If you can afford one),or a plain hybrid or even plugin hybrid will do just fine and give you reasonably high mileage without range anxiety since once a smallish battery is empty it behaves like a regular hybrid. In our family, I'd probably have one of the cars an EV and the other- a hybrid. Covers all usage patterns for us and we could swap as needed.

On taking the power plant from Tesla to another car- good luck there. Model S was designed from ground up as an electric car. That's why when you see  a bunch of EVs at a car show, all but Teslas have engine-like things under their hoods. That's the space they had to jam electronics. Tesla has a "frunk" instead ';)
« Last Edit: September 29, 2013, 08:11:05 pm by reagle »
 

Offline reagle

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #79 on: September 29, 2013, 08:13:33 pm »
Forgot to mention- a model S owner was nice enough to give us some fun rides. The thing accelerates like a jet liner, minus the shaking and vibration. You just keep waiting for it to take off. Pretty insane!

Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #80 on: September 29, 2013, 08:24:57 pm »
&elgonzo . crash and safety ? The Tesla is the safest car ever tested. It outperforms any car in any test. It even outperforms all cars in different categories in all tests.

You certainly misunderstood. Flipping the car or even doing artistic barrel rolls with it would not impress the battery much (i hope so).

It is impact crash scenarios (you crashing into something, or somebody else crashing into you)  where battery safety
is a concern.  :o
 

Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #81 on: September 29, 2013, 08:31:01 pm »
Forgot to mention- a model S owner was nice enough to give us some fun rides. The thing accelerates like a jet liner, minus the shaking and vibration. You just keep waiting for it to take off. Pretty insane!

If you ever took a ride in an electric high-speed train, or took one of these many crazy rides in amusement/theme parks, you know what is possible. Asynch AC motors are not only powerful while being compact, they also forgive a lot of abuse :)


 

Online IanB

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #82 on: September 29, 2013, 08:37:40 pm »
Forgot to mention- a model S owner was nice enough to give us some fun rides. The thing accelerates like a jet liner, minus the shaking and vibration. You just keep waiting for it to take off. Pretty insane!

Even a tiny Spark EV can leave gasoline vehicles for dust at the lights. I was in one once, car plus three large adults. Driver in the other lane thought, "Hmm, toy car, I'll just nip ahead of it and cut across into their lane". Well, before their gasoline engine had finished revving up they were a receding image in our mirrors.

Unlike gasoline engines (which have zero torque at zero revs), electric motors have high torque at zero revs. Furthermore, electric drive trains don't have power sapping devices like clutches or torque converters in the power train. You get instant acceleration on demand.

One thing I've often been puzzled about is why cars have never been designed with electric transmissions like diesel railway locomotives. You could have a Prius sized battery, electric drive train, and small, lightweight gas turbine/generator set to charge the battery. You would get a light, fuel efficient, high performance vehicle.
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Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #83 on: September 29, 2013, 08:51:06 pm »
One thing I've often been puzzled about is why cars have never been designed with electric transmissions like diesel railway locomotives. You could have a Prius sized battery, electric drive train, and small, lightweight gas turbine/generator set to charge the battery. You would get a light, fuel efficient, high performance vehicle.

Simply costs. The advantage of diesel electric locos compared to diesel hydraulics is fuel savings (since the diesel can almost always run in its optimal operation range), but which only becomes significant in a high power scenario and the high fuel requirement that comes with it.

Diesel electrics are substantially more expensive than diesel hydraulics, and they do not pay off in any other than high power scenarios. Not surprisingly, even today new low/mid power diesel hydraulics are built, such as the Vossloh G18.

Gas turbine is a dead end for such applications (unless someone has a smart idea about it).
Also look at locos for an example. Many railway companies used / experimented with gas turbine locos (mechanical transmission as well as electric transmission), and they were not a success. Guzzling gas instead of saving it :)

I think you can apply this similarly to a hypothetical diesel/gas-electric car...
« Last Edit: September 29, 2013, 09:08:52 pm by elgonzo »
 

Offline nctnico

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #84 on: September 29, 2013, 09:52:33 pm »
Buzzz. The reason to use a diesel-electric (or diesel hydraulic) drive in a locomotive has everything to do with fine traction control. You'll have a hard time to get a diesel loc to pull up without spinning the wheels or wearing the clutch really fast. With an electric drive the power control is much more fine grained. In a car you'd just add more conversion losses. A combustion engine with a turbo can be made very efficient in a wide RPM range. That is exactly what the car manufacturers (with BMW in the lead) are doing nowadays. They use the turbocharger to adjust the (virtual) volume of the cylinder to make the engine run efficiently.
« Last Edit: September 29, 2013, 09:56:51 pm by nctnico »
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Online IanB

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #85 on: September 29, 2013, 10:10:18 pm »
Right, but we don't have to suppose that the reason for diesel electric traction in a locomotive is the same reason for using it in a car.

Consider that electric cars already have all the drive and traction components anyway. If we apply diesel electric traction arguments to cars we would conclude that electric cars don't make sense (isn't that what this thread is all about?).

However, people think electric cars can make sense. So far the biggest problem to be overcome is the size of the battery required and limitations on the range. So suppose we replace most of the battery with a small and light generator set. Doesn't that address the energy storage concerns, while leaving other benefits of electric motive power intact?

Now, it is true that we no longer get the cost saving of mains electricity over gasoline. On the other hand gas turbines can burn other lower cost fuels than highly refined gasoline, so they can still have a cost and ecological advantage. It has already been proven that jet aircraft can run on 100% biofuel.

Gas turbines historically do not work in cars because they have the wrong speed and torque characteristics to couple to an automotive transmission. But they have the perfect speed and torque characteristics for connecting to a generator. Add to this that a gas turbine can be made the size of a coke can (maybe a little bigger for automotive power requirements), and you have a viable alternative to a big, heavy gas or diesel engine.

This hybrid electric transmission is of course exactly how hydrogen powered vehicles would be expected to work (replace the generator with a fuel cell). So it is not a completely crazy idea.
« Last Edit: September 29, 2013, 10:11:56 pm by IanB »
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Offline nctnico

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #86 on: September 29, 2013, 10:23:43 pm »
Right, but we don't have to suppose that the reason for diesel electric traction in a locomotive is the same reason for using it in a car.

Consider that electric cars already have all the drive and traction components anyway. If we apply diesel electric traction arguments to cars we would conclude that electric cars don't make sense (isn't that what this thread is all about?).
Now you are twisting my words  ;D Again: diesel-electric drive trains in locomotives aren't about saving fuel but about fine grained traction control. In a car you don't need fine grained traction control so a combustion engine can drive the wheels directly.
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Offline NiHaoMike

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #87 on: September 29, 2013, 10:47:20 pm »
They are an obvious place we are heading to, but aren't there lots of intermediate steps first? Like regenerative braking, a DC generator dumping the power into some fast charge batteries or supercapacitors. The electronic engine management takes an astonishing current draw, I measured over 10A on just a simple ECU, so this generated power can be used quickly, within minutes. If you are in a jam then the regenerative brake can also do duty as a motor to trickle you along. Seems pretty basic, and simple, to me but no car has it. Why?
Actually, hybrids do have that, and even a few non hybrids have that as well.
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Online IanB

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #88 on: September 29, 2013, 11:01:15 pm »
Now you are twisting my words  ;D Again: diesel-electric drive trains in locomotives aren't about saving fuel but about fine grained traction control. In a car you don't need fine grained traction control so a combustion engine can drive the wheels directly.

I'm not twisting your words. I'm just saying that different reasons may apply for hybrid electric transmission in cars than in diesel locomotives. We don't have to say that the only reason for diesel electric transmission is fine-grained traction control, just because that is the reason in one application. (Actually, I don't necessarily agree with that reasoning either. The primary reason for diesel electric traction on railways is that mechanical or hydraulic transmissions are not able to handle the power requirements of the largest locomotives.)

In cars, you need motive power that has usable torque over a wide range of speeds. An internal combustion engine sucks at this, which is why cars need complex devices like clutches and gearboxes with many interchangeable gear ratios. What's more internal combustion engines need to be made larger to cater for the maximum demand, which means they run inefficiently at lower speeds.

Electric motors solve all these problems. They have strong torque at low speeds, so they don't need lots of gears. They don't waste power when stationary or running slowly. They don't need a clutch to prevent them stalling. Their speed and torque can be adjusted over a huge range using only electronics.

In engineering terms, electric motors are a far more suitable motive power source for cars than internal combustion engines are. The only reason combustion engines power cars as well as they do today is years and years of refinement to overcome the problems.
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Offline ampdoctor

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #89 on: September 29, 2013, 11:06:41 pm »
Every time I see discussions about electric cars, all I can think about is the massive screw ups our govt made in promoting green energy.  Think about it for a minute.  If when uncle sam bailed out GM they inserted the provision that you won't get dollar 1 unless every car you make is either fully electric or at a minimum 1/2 to 2/3 the physical production, the mfg's would be busting their asses coming up with solutions to all the major and most of the minor problems.  And with that quantity of electrics hitting the roads from one end of the country to the other, there would be no shortage of charging stations either.

The way it stands currently, no pun intended, unless you're a white collar worker making 100k/yr and living in a major metro area electric cars are a non starter.  Once you get into "fly over country" the vast majority of people can put every bit of 100 miles a day on a car without batting an eye. With average incomes substantially less than 50k/yr they better be damn cheap, have a lot of range, and be able to charge up right now! And that demographic covers one hell of a lot of people.

So the trick in my view is that for electrics to be viable in this country the major hurdles that need to be addressed are 1. they need to be available sub-20k for a utilitarian vehicle, 2. the usable range needs to be doubled at a minimum, 3. they need to be fully chargeable in around 15 minutes, 4. stations need to be made available in every one horse town from coast to coast.

I know most people here would say that those are unrealistic standards. But, if you want to get rid of fossil fuel vehicles that's the standard that needs to be achieved. Until that happens, electrics will be viewed as not much more than a toy for a bunch of urban yuppies with more money than brains whether it's a true statement or not. That's the hard reality of it even if it's a bitter pill to swallow for a lot of people.
 

Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #90 on: September 29, 2013, 11:19:59 pm »
Buzzz. The reason to use a diesel-electric (or diesel hydraulic) drive in a locomotive has everything to do with fine traction control. You'll have a hard time to get a diesel loc to pull up without spinning the wheels or wearing the clutch really fast. With an electric drive the power control is much more fine grained.

Nope, sorry, but wrong. That was not the reason why diesel electrics became the standard for heavy freight and passenger trains (on unelectrified lines) during the 1960s.

Old diesel electrics don't provide superior traction contol. Spinning wheels were avoided in the past by the generous use of sand.

Older electric locos by the way were lacking fine control too. They controlled motor power by using big power resistors. The traction control/limitation of old electrics was actually so bad, that powerful freight locos could push the railbed/sleepers.

On the contrary, diesel-hydraulic transmission was and is is preferred in switchers/shunters because it offers a rather smooth change of power which is important due to frequently occurring accelerating/decelerating with freight. And no, they don't need a clutch.  :o

Clutches you will find only in low-power light-weight passenger units, as mechanical transmission is not a good choice for any train with a bit of weight...

Fine traction control for electric drive train started to become a reality in production locos during the 1980s with the emergence of reliable high-power IGBTs which allowed the use asynchronous AC traction motors as well as efficient, fine traction control.
However, diesel electric traction predates this development several decades, and your argument would only make sense if you have a time machine.  ;D
« Last Edit: September 29, 2013, 11:34:22 pm by elgonzo »
 

Offline nctnico

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #91 on: September 29, 2013, 11:57:30 pm »
Now you are twisting my words  ;D Again: diesel-electric drive trains in locomotives aren't about saving fuel but about fine grained traction control. In a car you don't need fine grained traction control so a combustion engine can drive the wheels directly.

I'm not twisting your words. I'm just saying that different reasons may apply for hybrid electric transmission in cars than in diesel locomotives. We don't have to say that the only reason for diesel electric transmission is fine-grained traction control, just because that is the reason in one application. (Actually, I don't necessarily agree with that reasoning either. The primary reason for diesel electric traction on railways is that mechanical or hydraulic transmissions are not able to handle the power requirements of the largest locomotives.)

In cars, you need motive power that has usable torque over a wide range of speeds. An internal combustion engine sucks at this, which is why cars need complex devices like clutches and gearboxes with many interchangeable gear ratios. What's more internal combustion engines need to be made larger to cater for the maximum demand, which means they run inefficiently at lower speeds.
The latter is not quite true. A combustion engine doesn't have a single point where its most efficient. It runs most efficient when it needs to provide near full power at a given RPM. This means that for a given speed the gear ratio must be choosen in a way the RPM of the engine is as low as possible. I tested this with my own car by tuning it to have more power at low RPM so I can drive in a higher gear. This resulted in a fuel saving of about 5%. The use of a turbo charger can increase the range in which the engine runs most efficient.

And please don't use torque. Torque is a function of RPM and power (power= torque * rotation speed in rad/s). What you want to accellerate a car is power (energy over time). If you get a constant amount of power from an engine the torque actually gets lower with increasing speed. Since power (energy!) cannot be lost the car will still accellerate. If you have an engine with a constant torque you start with very little power which increases as the RPM rises. In other words: torque works counter intuitive. Lots of torque doesn't mean fast accelleration and torque getting less doesn't mean the car is slowing down.
« Last Edit: September 30, 2013, 12:03:22 am by nctnico »
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Offline free_electron

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #92 on: September 30, 2013, 12:03:51 am »
I've visited a local plug in day as well, and I drive hybrid so here are my two cents
-snip-
 And they were represented by their owners, not sales droids. Huge difference. You get to see real people who are happy with their cars and can tell you their real life experience. I am not at all surprised that a given sales droid from a stealership was clueless.
-snip-
 Model S was designed from ground up as an electric car. That's why when you see  a bunch of EVs at a car show, all but Teslas have engine-like things under their hoods. That's the space they had to jam electronics. Tesla has a "frunk" instead ';)

Here is a bit of information deliberately left out of the conversation so far, to see where this would go. (It is a RANT after all. i wanted to see what other people, informed and uninformed think about it. i use this information to get a better view of how people look at these cars.)

I also talked to OWNERS of Nissan Leaf ( 3 of them and this was AFTER my interaction with the official dealer ) and the FIRST thing all three told me is that it is ONLY a COMMUTER car. Don't expect it to be able to become your only car. One even admitted that he drives from San Francisco to the lower bay area every day and HAS to charge it where he works. Frequently he has to send emails to his colleagues or chase em down if they will please move their electrics when done charging so he can charge to get home.... sometimes he works late because the car is still charging...The actual owners were honest.

I also talked to Volt owners and Tesla owners. Those guys seem to be the happy crowd without the range anxiety. So are the plug-in hybrid owners. The Rav4 EV .. there was only one and he had mixed feelings about it.

And yes, you are right. ALL electrics that were on show had all the stuff crammed in the area where the normal combustion engine would be. Only the Tesla is engineered to be electric from the ground up.

So this leads me back to another question i keep on asking :

 Why can't the other car makers do that (engineer it from the ground up)?

- Are they so set in their ways they can't change ? They have become dinosaurs that have lost the ability to evolve ?
- They can't innovate ?
- They are simply not interested in it ?
- They are scared of it ?
- They want it to go away ?
- They are technologically retarded ?
- they are afraid the higher price will turn people away ? ( the Tesla outsells basically all other cars in its price category like BMW M5 and 7 series , Audi A8 and many others ... so that can't be it)
- it is a deliberate attempt at sabotaging it ?
- it is a conspiracy because the manufacturer-dealer-petrolpump business model is threatened ?

What is it ? one , multiple, or all of the above ?

It CAN be done. the Tesla is living proof of it. I drove one yesterday at the plug-in event and i drove one at the factory this morning (yesterday was rush rush and they didn't go over all the things the car has, so i went to the Tesla store at the factory to get the full details).

Technologically this car is completely different and the end result is something unlike our perception of an electric car. It does take off like the enterprise going into warp. The charging technology is unlike anything out there. It's got the range and it is a very comfortable luxury car on top of that.

 It really leaves all the old stuff behind. Both in the technology and engineering of the machine and at the stoplight...
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Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #93 on: September 30, 2013, 12:04:58 am »
Consider that electric cars already have all the drive and traction components anyway. If we apply diesel electric traction arguments to cars we would conclude that electric cars don't make sense (isn't that what this thread is all about?).

However, people think electric cars can make sense. So far the biggest problem to be overcome is the size of the battery required and limitations on the range. So suppose we replace most of the battery with a small and light generator set. Doesn't that address the energy storage concerns, while leaving other benefits of electric motive power intact?

If you take costs out of your consideration, everything that is possible within the confines of physical laws and doesn't harm humans should be possible :)

What you suggest we have already in a somewhat different way, which is called hybrids. The idea behind these is (i just noticed that, loosing interest in hybrids long ago, i actually don't what their current selling point is. So please forgive me if i now start to utter total BS :-//) that the e-drive takes over from the gas engine when the gas engine would need to operate in an unfavourable range. Uhm, is that what hybrids do??? ;)

Consider a hybrid to be converted into a petrol-electric. Without considering any engineering details, you would need to swap the gearbox and the hybrids weak e-motor with a generator plus e-traction motors. Again, if you don't mind cost, it should be possible. If you mind cost... but let's rather stop here... it's like beating a dead horse :)

Gas turbine. Honestly, i don't know. There was not much visibly going on with gas turbine-related transportation in the last 30...40 years, except the odd concept, prototype, testbed or gas-turbine bus here and there. Russia dabbles a bit more seriously in gas-turbine-electric locos, but they are the largest exporter of LNG and have 2nd largest natural gas reserves in the world, so that would count as a special case.
 

Online IanB

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #94 on: September 30, 2013, 12:17:30 am »
And please don't use torque. Torque is a function of RPM and power (power= torque * rotation speed in rad/s). What you want to accellerate a car is power (energy over time).

I'm an engineer. I have to use torque  ;)  Torque is what is required to convert power into speed.

There's a rather unfortunate consequence of your equation above. If a machine is stationary, the rotation speed of the wheels is zero. This means that the applied power is torque * zero = zero. According to this formula, no stationary vehicle will ever start moving...
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Online IanB

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #95 on: September 30, 2013, 12:23:00 am »
Gas turbine. Honestly, i don't know.

I don't know either. Small gas turbines are used quite effectively in any number of executive jets out there. They run for hundreds or thousands of hours with only a moderate amount of servicing. Large gas turbines run in power plants 24 hours a day with no problems at all.

I'm not at all sure why gas turbines have such a hard time getting outside their current application areas. It's probably due to a lack of familiarity and availability of service personnel. If your car had a gas turbine in it hardly anyone would know how to service it.
I'm not an EE--what am I doing here?
 

Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #96 on: September 30, 2013, 12:37:30 am »
It really leaves all the old stuff behind. Both in the technology and engineering of the machine and at the stoplight...

While i never had the chance to drive a Tesla myself, i can totally imagine how you feel.

Just look at the power requirements of these amazing amusement park thrill rides (here an older version of the Mondial web site, the current web site doesn't seem to show tech. specs.). Seldomly they need more than 200kW, often less or just a bit more than 100kW. If you have once looked at those power requirements, you can't help but smirk at the driving performance of petrol cars. And never ever again you can look at a Bugatti Veyron without maximum ROFL...
 

Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #97 on: September 30, 2013, 01:13:18 am »
Gas turbine. Honestly, i don't know.
I'm not at all sure why gas turbines have such a hard time getting outside their current application areas. It's probably due to a lack of familiarity and availability of service personnel. If your car had a gas turbine in it hardly anyone would know how to service it.

Perhaps it is one of those forgotten technologies.
Like NASA, who lost expertise in heavy lifter rockets (Saturn 5), and has to study the decades-old F-1 rocket engines, to re-learn what their grandfatherly engineers were doing in a time long before our time.
« Last Edit: September 30, 2013, 01:16:53 am by elgonzo »
 

Offline Psi

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #98 on: September 30, 2013, 01:44:15 am »
Again, with the utmost respect, it sounds to me that you just wanted to put the poor car guy in his place and show him how big your intellectual dick is. 
No it doesn't. If he'd told me. Well our car is targeted as a short commuter car or for people that want to use it as a second car, i would have thanked him and walked away. With those premises set : short commuter, or ise as second car it would have been acceptable.

Him going off telling me to buy a second gasoline powered car or suggesting me to rent one

They would never say upfront that the cars only suitable for X and you need a 2nd car for the long trips.
It goes against everything taught in sales/marketing school. eg
- Never voluntarily mention the negatives of the product
- Always provide solutions if the customer asks about the negatives

Don't get me wrong I find this annoying too.
Stupid marketing people leaving out the important facts, but you can't verbally attack them for it.
It's the entire marketing system/culture that has the problem. They're just doing their job and trying to get you to buy the product.

Attacking them for doing their job is like killing the messenger, and calling them out in front of other potential buyers (who may be perfectly suited for the product) is just sad.

« Last Edit: September 30, 2013, 01:47:29 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline elgonzo

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Re: [Rant] Electric cars, in particular Nissan Leaf
« Reply #99 on: September 30, 2013, 01:58:02 am »
And please don't use torque. Torque is a function of RPM and power (power= torque * rotation speed in rad/s).

No, not RPM. Diameter...

Big diameter = High speed, low torque:


Small diameter = Low speed, high torque:


Now, don't come and tell me that trucks usually have bigger tires than sports cars. I wouldn't know what to say  :-//

But thank you for giving me the opportunity to post pictures of steam engines in a thread about electric cars  O0

(EDIT: I know, that this is not the correct defintion of torque, but i simply couldn't resist... )
« Last Edit: September 30, 2013, 02:17:52 am by elgonzo »
 


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