The Electric Supercar

[Trip]

According to the rumor, the short life of the hybrid is due to the newness of the technology. Perhaps newer hybrids are better I dunno. This is just what a friend told me when I mentioned I thought it'd be fun to own a hybrid or electric car.

[nici]

No offence to your friend, but i dont think he's correct. After all a hybrid is just a normal internal combustion engine coupled with an electric motor, with some electronics to control it all and batteries to power it. That's simplified of course, but that's basically what it is. And if anything breaks, you can repair or replace it.

Hybrid technology is also used in stuff like submarines, buses, and mining equipment. Obvously it's diesel or nuclear then, not petrol.

[AZBrandon]

There's been a lot of > 100k milers over on greenhybrid.com without any issues. I've seen claims of 200-250k from the 2nd generation hybrids (meaning 03+ Prius and 06+ Civic) due to improved battery cycle management. Many of the 1st gen hybrids went too deep on discharge and charged too high. Now they try to keep the SOC (state of charge) between 30 & 70% according to most of the docs where the early ones would do 20-80%, which apparently results in about half the battery life as keeping it within 30-70% of maximum charge.

[NeilBlanchard]

Hello,

The NiMH (nickel metal hydride) batteries in the current Prius are warrantied to last 100, 000 miles, and each cell can be replaced separately, so you can replace only the worn out cells.

Here's a site that answers some of the basic functions of a Prius:

http://www.howstuffworks.com/hybrid-car5.htm

Other hybrids work very differently.

[andyb]

dont know how I missed this one - it actually looks (slighty) sensible, cheap, very economical, you can even fit 4 humans into it, or 2 humans and some shopping. They need to work on the doors a bit though - this is when the designers were smocking Crack when they should have been drinking coffee.
http://www.dailytech.com/Article.aspx?newsid=1000
http://www.loremo.com/design_en.php?p=1&s=3


This is just ridiculous to look at but it is somehow very cool and can do 230mpg at 55mph and only costs $20,000.
http://www.dailytech.com/article.aspx?newsid=6470


Andy

[NeilBlanchard]

Hello,

Well, the entry doors are a bit unusual, but they are are integral to the overall design -- low weight while maintaining enough strength to remain safe in a crash.

[jaganath]

From the second DailyTech article:

The Aptera looks nowhere close to being road legal in its current form and its "distinctive" shape is sure to puzzle many onlookers.

The Aptera looks the way it does because that is the ultimate aerodynamic shape, a tapered teardrop. Also note the wheels are covered, they can also be a large soure of drag.

[NeilBlanchard]

Hello,

An interesting development for lithium ion batteries:

http://arstechnica.com/news.ars/post/20 ... acity.html

This will help electric cars -- and electric devices, too!

[klankymen]

dont know how I missed this one - it actually looks (slighty) sensible, cheap, very economical, you can even fit 4 humans into it, or 2 humans and some shopping. They need to work on the doors a bit though - this is when the designers were smocking Crack when they should have been drinking coffee.
http://www.dailytech.com/Article.aspx?newsid=1000
http://www.loremo.com/design_en.php?p=1&s=3
Andy

I don't get it. Where's the hitch??
This is like a 2Watt Core 2 Duo T7600 for $59.95, with perhaps the one condition that you are restricted to using a thermaltake case.

[Beyonder]

You're free to believe whatever you want to, here is the study.

http://cnwmr.com/nss-folder/automotiveenergy/

It was conducted by CNW Research. It states that it's 450 pages, so it might take you a while to go through it all. I believe that it became press-worthy (which is different than "people caring" as you called it) after hybrids came out because hybrids claim to be good for the environment. If you have to use way more natural resources in production just to save a little in operation, that isn't good for the environment. Hybrids make a claim that may not be true, that's why it's press worthy.

That study is absolutely questionable. For starters, it estimates the life of a Prius at 109,000 miles, which makes almost no sense whatsoever. CNW Research offers this rather breezy explanation:

The 100,000 mile life expectancy for Prius is time as well as distance sensitive. The historical data shows early Prius models were driven an average of only 6,700 miles per year (rounded). At that rate, the vehicle would require 15 years to reach 100,000 miles. It was our determination that is highly unlikely the '05 or '06 Prius models would still be in active service let alone serviceable 15 years from today.

...so, the authors arrived at this figured based on the fact that the average yearly mileage driven by Prius owners was 6,700 miles (how they arrived at this figure, and on the basis of what evidence, I have no idea). The study itself alludes to similar ambiguity surrounding the life-of-vehicle estimate:

It should also be pointed out that on a Dust to Dust basis, the Estimated Miles doesn't mean the vehicle is used up”and has no life remaining, only that this is the approximate mileage at the time it is removed from the streets as a daily-use vehicle and sent for disposal as either a source of parts or eventually scrapped.

...the study does not say if it computes the lifespan of a car based on the same criteria used to compute the Prius' figure of 109,000. And looking at their list, I find it very suspect. This report isn't calculating the cost of a given car anymore, so much as it's attempting to quantify the use of the car.

To compare an H3 or an H1 to a Prius, then, the authors would have to adjust the mileage appropriately, and the "final numbers" shouldn't be a "final number"--they should be a "final graph," where the cost per mile varies based on the number of miles someone actually drives the car. Producing a single number as the final output, and then ranking them, is absolutely misleading. I'm sure there are other constants they arrived at that are actually estimated ranges, but for simplicity at the expense of accuracy, they fudge it.

In my opinion, this study is a bunch of rather uninteresting numbers, thrown together by someone who statistically doesn't have a leg to stand on. You could poke holes in CNW's methodology all day long.

[Beyonder]

Someone told me the other day that the downside to hybrids is that they don't last past 100K miles.

Is this true as well for electric cars despite their having (I guess) no moving parts?

This is false. The batteries in Prius (and most hybrids, I believe) are warrantied to 100,000 miles. It doesn't mean they fail at 100,000 miles. Same thing as automotive transmissions--most are warrantied to 100k miles, but they almost never fail that quickly. My family has had three civics, and two of them died with the original transmission around 230k miles. A third still has the original transmission, and it's at about 205k miles, I believe.

[jaganath]

The historical data shows early Prius models were driven an average of only 6,700 miles per year

That's a low mileage; in the UK the average driver drives 12,000 miles per year and I would imagine in the US it's more. I suppose early Prius adopters would have been very "eco-aware" so didn't drive much.

Is this true as well for electric cars despite their having (I guess) no moving parts?

electric cars have moving parts (generator/motor,transmission,regen brakes if fitted).

[NeilBlanchard]

Greetings,

Here's a news item that may have a big affect on hybrid/electric cars, as well as many other things:

Ars Technica news item on super capacitors

[cansan]

Just curious, does anyone know how much the battery + electric motor in the Prius weighs?

I really wish someone would buy two identical Priusses, strip one of them down to a basic car (toss out everything related to the "Hybrid Synergy Drive" or whatever its called), and test them to see which one uses more fuel.

I just cannot see the hybrid one using less fuel with all that extra weight. Is it just me?

[NeilBlanchard]

Hello,

It may improve the mileage for highway, but the city mileage (which is far higher than the highway) would probably suffer. Having the batteries allows it to "reclaim" power by using regenerative braking, and having it shut off completely while in stop and go traffic is nice, too.

I'm sure that the weight of the batteries is the main thing -- the electric motor works in tandem with the small-ish gasoline motor, so if you didn't have the electric motor, the gas motor would have to be larger -- or the performance would be lowered a fair bit.

The rumor about the next generation Prius, is that it uses lithium ion batteries in place of the nickel metal hydride -- they weigh a lot less, and they are more powerful, so it's mileage may be 94mpg.

[cansan]

Yes, I agree that having it shut off completely while in stop and go traffic is brilliant. However, I think capturing braking energy is more hype than substance. To capture a useful amount of braking energy you would ideally brake softly and stop over a long distance. But in city driving your braking is often dictated by other factors. This maybe why people in the real world rarely get the fuel consumption numbers in the Prius brochure.

Of course without an electric motor, it may need a bigger engine, but is that such a bad thing? The Prius has a 1.5 4-pot. You could have a 1.8 or a 2.0 with a very small penalty in weight. Now, combine this with 10-15% longer gearing, and the highway consumption would be a lot lower. You would need less revs thus less pumping losses.

As for the 94 mpg claim, I wouldn't be surprised to see it on the brochure, but I would bet a lot of money that it cannot be achieved in the real world.

Funny enough, I live in Germany, where fuel is expensive and the people who are concerned with fuel consumption all drive diesels, not hybrids...

I think the future is a series hybrid; small 2-cylinder diesel engine of 30-50hp, fast charging, de-charging small battery, 60-100hp electric motors. Engine runs all the time at its peak efficiency, battery makes up the difference between the constant power from the engine versus the power needs of the vehicle. You still have the weight penalty but in exchange you have high efficiency all the time. Plus having the engine decoupled mechanically from the wheels could allow more aerodynamic tricks, lower nose etc...

[jaganath]

I think the future is a series hybrid; small 2-cylinder diesel engine of 30-50hp, fast charging, de-charging small battery, 60-100hp electric motors.

future? more like present:

http://www.greencarcongress.com/2007/06 ... advan.html

GM will unveil a third E-Flex application at the Frankfurt show in September: an Opel concept model that uses a diesel engine in combination with the electric drive system of the E-Flex architecture.

if we only had to forecast the present weathermen would have a lot easier job.

[cansan]

Well, displaying a prototype is not quite the same as going into a showroom and buying it. Volvo is also going to be displaying a prototype:

http://www.autobloggreen.com/2007/09/06 ... es-hybrid/

Even then, these are not cars built from the ground up to be series hybrids. They are just conventional cars modified into series hybrids. Series hybrids could potentially have much smaller engines like 600-800ccs. This may completely change the way normal cars are designed. Though I have to say, the specs on the Volvo look nice, but I have to wonder how heavy the electric motors in the wheels are?

But as of today, all you can buy are parallel hybrids.

[flyingsherpa]

However, I think capturing braking energy is more hype than substance. To capture a useful amount of braking energy you would ideally brake softly and stop over a long distance. But in city driving your braking is often dictated by other factors. This maybe why people in the real world rarely get the fuel consumption numbers in the Prius brochure.

Regen braking is not hype, it is the primary reason hybrids like the Prius are more efficient. Think about it... all the energy in a Prius still comes from the gas engine. All the energy in the battery came from the engine charging it or from regen, but even regen is just capturing back energy that the gas engine put out. Regen is the only thing that makes it different than a normal car.

Yes, the Prius uses a very efficient gas engine, but it's also on a different cycle (Atkinson vs normal Carnot) which is not very responsive on its own... no one would buy an Atkinson-cycle purely gas car, they tried that in the 70s I believe. The electric motor assist makes using that engine more acceptable performance-wise.

People who don't drive their Prius like idiots do get the numbers in the brochure.

I've heard rumors that the next generation Prius with the lithium battery might also be a partial plug-in. This is really where you can get much better efficiency... adding energy directly to the car that doesn't come from gas (and then running the car on electric only whenever possible/practial). Off-peak electrical rates are MUCH cheaper than gas in terms of cost per mile.

I believe serial hybrids will be big once the battery tech gets cheap and reliable enough, but they must be plug-in to make it worthwhile.

[NeilBlanchard]

Hello,

Regenerative braking is real -- the conservation of energy applies. Instead of dumping all the forward momentum into heat (via the brakes), it uses the same electric motor that (helps) move the car, as a generator, to (partially) recharge the batteries, so it can then be "reused". Of course, you lose energy to friction, as always, but AFAIK, the Prius only uses it's mechanical brakes in emergencies -- most of the time it only uses regenerative braking.

The other point of (better) efficiency with a hybrid, is in the use of the electric motor for starting and at low speeds. An electic motor has peak torque at 0 RPM, and this is why the Prius gets it's peak "mileage" at speeds up to 40-45mph. Above that, it only uses it's gas motor, which is better than electric at these speeds, but it still cannot match the efficiency of the electric motor.

[Eagle156]

Oh yeah, and the cars are silent

What's the point of that? Cars are meant to sound nice and loud, especially sports car. You know hell has been frozen over when a car is silent.

[djkest]

I saw a video of an electric car that beat a viper and corvette on the drag strip. Only downside was they used like $200,000 worth of laptop batteries to power it.

I think the Prius is a little over hyped. Most prius owners I've seen are driving their cars incredibly slowly, afraid to accelerate. Even finding a big truck to tailgate to try and draft. All that silliness to try and max out their fuel economy. It's been proven it takes 10-12 years to make back the extra cost in initial price by gas savings... and the environmental impact of all those batteries is something you don't' hear the greenies talk about much if at all.

[NeilBlanchard]

Hello,

I heard about a "super capacitor" that may beat out batteries.

[NeilBlanchard]

Greetings,

I just heard a very interesting story on the radio, about a woman, Christina Lampe-Onnerud, who redesigned the "guts" of a typical lithium ion battery -- and it lasts much longer, charges faster, and greatly reduces the likelihood of overheating/bursting into flames! Her company's name is "Boston-Power", and their battery called the "Sonata" is in production, right now.

It charges in ~1/2 the time of regular batteries (80% in just 30 minutes!), and it lasts much longer, too.

http://www.here-now.org/shows/2008/09/20080908_9.asp

http://www.engadget.com/2007/01/30/bost ... p-battery/

http://news.cnet.com/Start-up-to-launch ... 54414.html

http://laptoping.com/boston-power-sonata-batteries.html

http://news.thomasnet.com/companystory/538004

http://www.boston-power.com/

Cool stuff!