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Discussion Starter #1
Ok, GM, here's what ya' do. The serial hybrid thing is a bonafide winner. I'm convinced from a week of reading. My gosh, you can make it do anything a ICE only car can do, only much more efficiently. You have only one problem here with trying to produce an electric-as-possible car. The battery is lagging, by some combination of technology and economy of scale. If I'm understanding correctly you can't quite produce a nearly-all-electric car and price it competitively.

Okay, so you're waffle-iron's cord ain't quite installed, yet. Make pancakes! Produce some serial hybrid models where you don't care how many miles it goes on a battery charge. You can still make it get 50, 60, 70 miles/gallon of gas can't you? Could you not:

1) design an econo-box, typical, low power little thing that quite a few people in cities would be willing to commute in, and by just focusing on it as an efficient-as-possible serial hybrid, like a diesel locomotive, have it get ridiculous mileage. Isn't that feasible? With a just-big-enough-to-act-as-a-voltage-buffer battery (you do need that, don't you?) could you not price this ridiculous-mileage econobox competitively?

2) Design an Aptera-like Jetson air-cutting thingy that gets just INSANE mileage? Also price it competitively.

3) Install serial hybrids, again, not worrying about how far you can go till the genset (Is that correct jargon?) has to kick in, in Camaros, Silverados and Malibu/Impalas. Could you provide all the power anyone could want while REALLY extending the mileage a similarly accelerating current model gets, AND price it competitively?

Dude! Don't force the technology. Keep bringing the LI and other batteries along, they're going to be great. But no one's (not enough people) are going to buy the mostly-electric if they can't afford it. For the near future, use whatever sized battery you can make competitive and PUSH THE MILEAGE!

Am I right or not?
 

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So what are you trying to say exactly? Sorry, I'm not following...
WopOnTour
 

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Discussion Starter #3
I'm saying forget about any particular miles per charge. It's too expensive for the present. Focus on putting series hybrids out there that get fantastic mileage at a wonderful price and are reliable. You'll sell millions. You can put them in a lot of different models. Extend the miles per charge on the batteries as technology and economies of scale make that option cost effective.
 

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Discussion Starter #4
I still don't know if I'm clear. Use only as big a battery as you need for a series hybrid where you're not trying to get any particular miles/charge. The gasoline mileage is what you're after, because THAT'S affordable right now.
 

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Well, basically I believe that's exactly what GM is doing with the Volt. I don't think they are totally satisfied with the power density and size/weight of the current technology. If you've seen photos of the Lithium Ion pack for the Volt, it's quite large and weighs 400lbs. It had to be configured in a T-shape just to be able to fit it into the vehicle and still leave room for passengers and payload. But they are moving forward anyways- while continuing to drive battery research forward.

But to just hybridize their entire fleet, certainly cannot happen overnight.Creating series hybrids with motors large enough to propel a pickup truck to highway speeds though, that's another issue...

WopOnTour
 

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Discussion Starter #7
WopOnTour: No, what they're doing that endangers the feasibility of the series hybrid is holding everything hostage to the 40 miles/charge gimmick. That's great for the Volt, but ensures that the series-hybrid drive model only occupies a tiny niche. It's too expensive for nearly the whole driving population. By abandoning the idea of getting any particular mileage from the battery, could GM not make series-hybrids competitive throughout their (GM's) entire model range? Again, if I'm understanding the series-hybrid concept correctly, that wouldn't accomplish anything in particular except to increase each of those model's mileage ratings BY A LOT. Oh, yeah. They'd also be, in theory, more dependable. Is this a good idea, or not, or do I have something wrong here?
 

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I've been thinking about this a lot. If the volt had a smaller battery it would be quite a bit cheaper but still get great mileage. What ever happened to the supposed 20 mile AER model GM used to talk about? That would sell like hotcakes.
 

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I greatly anticipate and have been lobbying for GM to proliferate the EREV to as many models as possible, but only in time. It would be corporate suicide to try to design, engineer, and tool up to produce all of these at once. They have to start somewhere and with a reasonable amount. Remember the first iteration of the EREV will be the worst iteration. There will be tremendous opportunities for them to advance and improve the EREV but they have to produce some first. They need experience producing them and with customers driving them. The 40 mile, family sedan with decent performance and some style is a pretty good place to start.

They only avenue that I think would have been better would have been a more upscale uproach. I have always thought it should have been a Cadillac first. The price premium is much more palatable when the price is only 25% higher. If they took a $15K econobox and made it a $25K EREV, it would be a 67% increase in price. Even though the battery is the most expensive component, there are also a lot of other EV related costs that are fixed to the power demand and not the battery size. You can't shrink the battery too much, because then you run into power issues. I do think they can take 4KWh out the battery, but don't think the A123 or LG Chem chemistries will allow them to reduce beyond this.

I'm sure GM is still planning on a less costly, shorter range EREV but that will be best served by Gen 2 EREVs.
 

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Discussion Starter #10
Even though the battery is the most expensive component, there are also a lot of other EV related costs that are fixed to the power demand and not the battery size. You can't shrink the battery too much, because then you run into power issues. I do think they can take 4KWh out the battery, but don't think the A123 or LG Chem chemistries will allow them to reduce beyond this.

I'm sure GM is still planning on a less costly, shorter range EREV but that will be best served by Gen 2 EREVs.
That's all good information. I wonder how small a battery would serve an EREV. My hypothesis, if you can call it that, is predicated on the idea that carbon fueled vehicles will, by technological necessity, be with us for quite some time to come. Why not make them as efficient as possible by switching our current ICE-only drive trains to series hybrids? -But I don't mean overnight or anything, just to do it. I wonder if GM has THAT much imagination. The Volt can be cynically pictured as a PR gimmick if it can't be priced to truly compete.
 

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jonbo
No offense, but it sounds like you just don't understand the "implications" of a series type hybrid drive. This requires much more powerful motors (and therefore more powerful power sources) The 2 go hand-in-hand.

The Volt is about as big of vehicle that could be pushed by a 100kW continuous motor in a series configuration. Series-parallel hybrids, (like most all others out there) do NOT require anywhere near this level of electrical power. For example the 2-mode GM-Allison transit bus transmissions have about the same motor capacity (~100kW) but in a 1000lb transaxle needing 1000lbs of 600V battery!

AFAIK a 200kW motor capable of pushing a series hybrid truck with twice the mass and ten times the drag of the Volt doesn't even exist in a package that would fit in the box!
I'm sure GM is still planning on a less costly, shorter range EREV but that will be best served by Gen 2 EREVs.
That's a good one!

Everyone has some idea of what range/charge they would consider ideal for their own purposes.
But I've never heard anyone put up a such a "good" argument for SHORTER RANGE.
Maybe get some T-shirts. "The World Demands Short Range Hybrids!"
WopOnTour
 

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What do you have against small AER serial hybrids? They would be cheaper but still very efficient. Would you complain if they made a 20 mile AER volt?
 

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meh

I don't think the point is the shorter range but the 6-7k it would cut off of the battery/car cost. Release a 20 mile version and a 40 mile version. People will want the 40 mile version, but if they can't afford it or the extra 20 miles would do them no practical good on their average commute to work they could buy the lesser range model at a much reduced price. The only real problem I see with it is if the power density wouldn't be high enough with only 8kw/h worth of batteries. You definitely don't want to cook the batteries by overworking them.
 

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What do you have against small AER serial hybrids? They would be cheaper but still very efficient. Would you complain if they made a 20 mile AER volt?
Again, the battery itself is just a small portion of the complexity and cost. It's the rest of the series hybrid drive that's the challenge and expense. Making the massive amounts of torque you require, as compact and integrated as possible, and then creating an electronic motor drive system to power it as effectively as possible. You don't just connect the battery to the motor and it runs. There's banks of HUGE heat laden high-speed IGBTs to deal with, not to mention the processing power and the cooling systems.

You create the drive and THEN try to fit the maximum battery power density you can carry depending on available space and payload capacity. Whatever you end up with determines your range. The 40 mile range of the Volt is what they ended up with, even though this might have been hundreds of miles below the initial design goals. It isn't engineered the other way around.

So scaling back the power source to save $2000-$3000 (given the huge expense of the rest of the supporting cast) just to cut the range in half makes absolutely no sense at all. Do you really think this will determine ultimate "make or break" affordability?

JMO
WOT
 

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Discussion Starter #15
jonbo
No offense, but it sounds like you just don't understand the "implications" of a series type hybrid drive....

...The 40 mile range of the Volt is what they ended up with, even though this might have been hundreds of miles below the initial design goals. It isn't engineered the other way around.
WopOnTour
No, I certainly don't. I had the bright idea that one could get away with a much smaller battery if one abandoned the 40 mile/charge mantra, actually any emphasis on "electric" car and have an ultimately ICE driven vehicle but much more efficient than what we have now, and, critically, at a competitive price.

Can anyone tell me, definitively, that that's not feasible? I know you have to use batteries of some minimum capacity. I wonder what that is? What is the battery capacity on a diesel locomotive relative to the mass being driven. I guess a locomotive doesn't require a lot of acceleration relative to an automobile. My idea implies a much smaller battery to make it worth doing.

How big a deal is a larger, more powerful motor for a heavier auto? Can you still get away with not having a transmission? If you can, that's got to be a significant savings in energy loss, mass, mechanical complexity (although most of that's been long worked out).

As to your second statement from a later post: Are you sure that's the case? I had gotten the idea that they had constrained their design to a pretty fair extent by marrying the idea of a primarily electric vehicle, and that now, creating a battery with enough capacity at a reasonable cost/price was a significant issue.

Cheers.
 
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