GM, the Volt, and catching up

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 26 2007, 09:18 PM) [snapback]485848[/snapback]</div>

The widely discussed 2-pack plug-in Prius outputs 60 hp from the battery and has an 8 mile range. Up that to 20 mile range (scaling up the battery accordingly) and you have 150 hp. That's using the same battery as in the Prius since '04.

If you switch to Altair or A123 batteries, which can both put out 3 kW per kg, the pack would be much lighter and smaller. Your requested 160 hp (118 kW) could be producd from a 40 kg battery pack. As both A123 and Altair batteries store about 100 Wh/kg, the 40 kg pack would contain 4 kWh, enough for 20 miles range.

As for costs, mature (cobalt based) lithium-ion in 18650 format is around $400 per kWh, so one day when the Altair/A123 chemistries come down to this level through similar mass-production, they should reach about $1,600 for the 20 mile battery.

 

GM can not produce a good ICE car and they have been building those for 100 years. There is no way they are going to be able to produce an electric car that is good the first time around. They are stuffing it into a cobalt instead of producing a new frame, they are not even seriuos about this, it is all PR hype just like flex fuel and all that other BS green hype.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 26 2007, 08:18 PM) [snapback]485848[/snapback]</div>

First, I don't see 160 hp as necessary. You do not need to be able to accelerate and pass someone while driving 80mph up a 20% grade. I drive a 90 hp TDI and it will accelerate just fine and tops out at 137mph. (That top speed is verified by driving a rental on the autobahn in Germany)

HP is not the the measurement to look at when evaluating EV's and acceleration, torque is. Electric motors give almost 100% of their torque at 0 rpm which gives a huge advantage in acceleration over a gasoline engine. If you go to the EV photo album (http://www.austinev.org/evalbum/1223) you will find lots of people with EV's full of 2000 pounds or more of lead acid batteries for a total vehicle weight of 4500 lbs. The electric motor of choice is the Advanced DC 9.1" which has a continuous HP rating of 19 HP and a peak of 85 HP.

HP in a EV is not just determined by the battery. The motor and controller are also key to HP and Torque generated. It is you classic trade-off of go fast for a short time or go slow for a long time.

A factory series hybrid with a much lighter and higher capacity NiMH battery pack would need even less power. I am quite convinced that Toyota could give us a 50 mile series hybrid for about $30K. (It would have about a $8K battery pack that weighed 600 pounds. There is not need to wait for L ion except for patent issues.

The 1.5L 4 cylinder engine in the Prius is HUGE. With a series hybrid that I am talking about you would only need a 0.5L to 0.7L single cylinder engine that was optimized to run at a single speed. No complicated variable valve timing. It would weight no more than 120 to 150 pounds total. Even if the Volt isn't designed for it, it would be beneficial for the ICE to kick in and provide more power for acceleration if required. If you aren't going to design that capability you may as well leave the ICE out.

The transaxle in the Prius is quite inventive but still uses more than 2 gears. The power splitter uses 6 and the reduction to the axle shafts used 2. That is according the the diagram on Toyota's website and I'm sure it is a bit simplified for the public. I would love to see a cutaway.

 

<div class='quotetop'>QUOTE(clett @ Jul 27 2007, 09:44 AM) [snapback]486060[/snapback]</div>

When I say "we do not have the technology", I put in the size, cost and durability/reliability in the equation. In order for Prius HV pack to last long, Toyota officially discharge about 28 hp (according to spec). They have 10 years / 150k miles warranty. You'll need about 6 of these packs to get 168hp.

The weight will be 600 lbs. The cost will be $13k ($2,150 each). The range may not be 20 miles. You calculated the PHEV Prius is discharging more than 60% than the normal 40%. If Toyota can keep the same 10yr/150k miles warranty with the 60% discharge, it will be great. If not, we need to calculate with 40% and then we'll need to add a couple more packs.

600-800 lbs battery will not have much room nor spare weight for the passenger. $13k cost for the battery may not be realistic for 20 miles PHEV. It is just not realistic and the technology is not here yet.

I too think lithium battery is a more realistic solution here. Again 40 miles with $20k pack is much better than NiMH but still with that $20k price tag, it won't make it to mass market. PHEV-8 Li-ion Prius is much more realistic.

 

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 11:26 AM) [snapback]486119[/snapback]</div>

I too agree. Rav4-EV is doing fine with less than half of that. You need to ask GM because they spec the Volt that way. I think they did that because the A123 pack for 40 miles range do output that much power.

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 11:26 AM) [snapback]486119[/snapback]</div>

There are high power NiMH (Prius) and high energy density NiMH (Rav4-EV) and you can not have both. PHEV-50 for $30k? Not possible. See the calculation in my last post.


<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 11:26 AM) [snapback]486119[/snapback]</div>

Atkinson cycle is more efficient and cleaner than Otto cycle. They both require variable valve timing. Motor cycle engine size is too small to accelerate 3,000 lbs car in a series hybrid when the battery juice runs low. It sounds good but this compromise needs to be addressed. Higher emission from diesel or single cycle engine need to be addressed too.

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 11:26 AM) [snapback]486119[/snapback]</div>

You can not leave out the ICE because you are left with an electric car that can go only 40 miles.

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 11:26 AM) [snapback]486119[/snapback]</div>

I thought a planetary gearset (PSD) has only 5 gears but they never shift. Did you know that an automatic transmission has many (3-4) planetary gearsets? I thought every car has reduction gears. Planetary gearset is also in the differential.

It is true that a series hybrid will be mechanically much simpler but demands too much from the battery. I am saying series/parallel (HSD) also simplified by removing many gears, belts, motors (starter/alternator), etc.. You see HSD today because the battery tech allows it. A series hybrids are not here because it requires a very powerful battery pack that I don't think is ready for mass market yet.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 12:05 PM) [snapback]486137[/snapback]</div>

Where do you get the $20k for 40 miles estimate? A company making hand-made, one-of a kind, bespoke batteries for prototypes may charge that much but in reality lithium-ion is nowher near that expensive at all.

A single mass-produced 18650 lithium-ion battery, the type used to make up laptop and Tesla EV batteries, today contains about 8 Wh in its 44 gramme mass, and costs about $3 wholesale. That's about $375 per kWh, which for your 40 mile range would equal around $3,000.

The Altair and A123 batteries are set to be cheaper than this still, since they use much cheaper electrode materials (eg iron phosphate instead of expensive and flammable cobalt). Moreover, the safety and discharge profiles of Altair/A123/Valence batteries means you can make LARGE FORMAT batteries, which are inherently cheaper than making a pack from many small 18650 batteries. Also, you can discharge an Altair battery from 100% to 0% and back again as many times as you want, which you can't do with cobalt based batteries (negating wasted un-used storage). Watch the price of the A123 M1 cell drop as more people start buying the DeWalt drills.

 

<div class='quotetop'>QUOTE(efusco @ Jul 25 2007, 09:37 AM) [snapback]484620[/snapback]</div>

Yeah, sounds like same old Detroit marketing hype (of which GM is the absolute worst). They have some major technological hurdles to overcome and they plan on doing it in a very short period of time. Even if they get the Volt to market as planned (which isn't likely), I don't think I trust GM's current quality level enough to buy one. Toyota has a much better track record in implementing brand-new technological advances.

Still, it's nice they're talking about using a different approach than Toyota's HSD to get significantly better fuel mileage. The theory of using the electric motor as the sole propulsion device, with an initial, full, plug-in charge of six hours, than an additional, small ICE to maintain a certain level of charge in the batteries to allow an acceptable operating range, is intriguing (even if it is just hype from GM).

One of GM's greatest engineering achievement in drivetrains (if not the greatest) was the 1955 Chevrolet small-block V8 (a version of which is still used today). That's a tough act to follow. The Volt's drivetrain, if successful, would be a comparable achievement and I'm just not sure GM is up to the task.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 26 2007, 07:18 PM) [snapback]485848[/snapback]</div>

Sorry.

The IMA Gen 4 (HCH-II) does have EV mode. The only difference is that it only engages at speeds above 12km/h or 7MPH. Not as good and useful as the Prius' since you may only do a few miles at most in it.

MSantos

 

<div class='quotetop'>QUOTE(MSantos @ Jul 27 2007, 12:38 PM) [snapback]486198[/snapback]</div>

To be "EV", there cannot be any interaction with the engine... which is impossible for a hybrid without a PSD or a clutch. IMA doesn't have either.

Of course, with only a 15kW motor that doesn't have active cooling, you can't expect much anyway.

 

<div class='quotetop'>QUOTE(john1701a @ Jul 27 2007, 12:03 PM) [snapback]486220[/snapback]</div>

I'm sorry. I guess I got the "formal" definition of EV mode wrong. Many pardons.

I was under the precocious impression that it meant operating the vehicle solely and exclusively on electric with the energy acquired through the regenerative process... all the while not consuming any gas.

<I showed your post to my class this afternoon, and one of my students asked:> If it is not EV-Mode then what is it ? What do you think? Just for giggles, what is the widely accepted "manufacturer independent" definition of a full-hybrid?

Active Cooling: Good point.
What would be the minimum criteria/design attribute that would define "active" cooling in this type of an application?

Would you mind suggesting an authoritative reference source so that we can all brush up on these things?


Cheers;

MSantos

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 26 2007, 06:18 PM) [snapback]485848[/snapback]</div>

The official range for the NiMH EV1 was over 150 miles, I believe. The range for the lead-acid version was around 100 miles. Regardless, I could go over 100 miles in the lead car, and over 175 miles in the NiMH car. And I'm still not sure I understand the batter-to-hp connection. Yes, there is obviously SOME connection - but both of these cars were limited in output power by the chosen motor, not the battery. The NiMH version was capable of MORE battery output than the lead version, yet the NiMH version was a bit slower due to some controller changes.

a. That would still make for an awesome, inexpensive car.
b. With the money and weight saved from removing the ICE fuel storage, exhaust sytem, catalytic converter, etc... we can add more batteries and increase the range with only a slightly higher price tag.

If they can sell this thing for about $25k as promised, I'm definitely willing to go $35k to have a 150-mile pure EV.

Oooo. I'm gonna have to go with the EV1 for GM's greatest drivetrain achievement. And if the Volt is comparable to the Chevy small-block, then the EV1 is still king.

 

<div class='quotetop'>QUOTE(clett @ Jul 27 2007, 01:08 PM) [snapback]486179[/snapback]</div>

$20k is from an analyst estime. I'll have to find a link but it was all over the news when the Volt was announced.

A123 M1 cells used in DeWalt tools have 3 years warranty. Car cells need to last more than 3 times longer than that. A123 has M1HD cells for plug-ins. M1s are going for $100 (ebay) to $165 (retail) for the pack. Each cell comes out to $10 to $16.5. They have usable (80% discharge accroding to GM) 6 wh per cell. Therefore, you will need 2,667 cells to get 16 kWh. You are looking at $26k to $44k for the pack. The $20k that the analyst said made sense if GM were to buy bulk. My assumptions are that M1HD will cost about the same as M1 cells and life cycle is 10 years.

Edit: DC9360 pack retail pice is $290 not $165. WOW.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 11:26 AM) [snapback]486151[/snapback]</div>

The battery chemistry is the same. The difference is in the application. This is a combination of motor, controller, and battery.

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 11:26 AM) [snapback]486151[/snapback]</div>

I saw your last post. You are using a figure of about $2100 per 1.3KwH Prius battery pack. How did you come up with that number?

I came up with $550. That is from the $3800 charged to a Priuschat member for his replacement battery pack divided by 7, the normal automotive mark-up for service parts compared to OEM cost. That is $423 per KwH and I suspect still too high. According to Toyota's specs on the plug in Prius it will go 13k or 8.125 miles on it's 2.6 kwh pack so that is 3.125 miles / KwH. So for 50 miles you need 16 Kwh which would cost $6768 and weight 550 pounds. That makes a $30K PHEV 50 easily achievable if you start with a $15K car like a Civic or Corolla.

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 11:26 AM) [snapback]486151[/snapback]</div>

The Atkinson cycle is more efficient and cleaner that the Otto cycle but both still suffer from the compromise of trying to make an engine run efficiently and cleanly over a wide range of RPM's. Even with variable valve timing you only get 2 cam lobe profiles and it is still a compromise. In order gain maximum efficiency you need pneumatic or electronic valves that can be independently controlled in an infinite combination. A Otto cycle engine fixed to a single RPM can be optimized for this RPM and be both more efficient and cleaner than the Atkinson cycle engine that is used over a wide RPM band.

A single cylinder engine does not have higher emissions than a multi-cylinder engine. In fact, a single cylinder engine with it's larger combustion chamber is easier to tune for performance and emissions that the smaller chamber of a multi-cylinder engine. The single cylinder engine is also the least expensive type of engine to build. The problems with single cylinders engines is vibration and low maximum RPM's which means low peak horsepower.

A motorcycle-sized engine is not too small to accelerate a 3,000 pound car if the gearing is correct. In this case the gearing is taken care of by the high torque of the electric motor. For example, this small airplane tug with two 10 hp 48V motors is rated to pull 100,000 pound airplanes.



<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 11:26 AM) [snapback]486151[/snapback]</div>

I would be happy to buy such a car since it would satisfy 80% of my driving

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 11:26 AM) [snapback]486151[/snapback]</div>

You are correct, planetary gearsets do not shift and automatic transmissions have a set of planetary gears for each speed so they have from as few as 2 sets to as many as 7. I agree the Prius transmission is pretty slick but I think it would be even for efficent if they allowed for more traditional gearing or a true mechanical CVT combined with their system.

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 11:26 AM) [snapback]486151[/snapback]</div>

I don't believe that it is the battery that holds back the series hybrid but the automotive world's inability to break with tradition. Again, the Prius and all the other hybrids are conventional cars plus electronic components. The layout of the Prius is VERY conventional; front engine, front drive. The series hybrid allows the engineers to completely break out of the mold if they want too like GM has done with their skateboard concept or Honda has done with their most recent fuel cell car. Of course with the Volt, GM decided to keep to the same old tired layout.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 12:35 PM) [snapback]486292[/snapback]</div>

It has been reported that the cost of the *completely engineered* pack of the Tesla is $20k. Not just the raw batteries, mind you, but the whole unique unit that can be stuffed in any car. And this pack is good for over 200 miles... not 50+

 

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 05:09 PM) [snapback]486342[/snapback]</div>

That's like saying A123 cells has the same chemistry as the laptop Li-ion cells. The NiMH prismatic cells in Prius have much higher specific power than normal cells due to the "new electrode materials and newly developed cell connection structure, internal resistance were reduced, and reliabilities, such as battery life". That is just an improvement over Gen1 Prius. I do not have details of the improvements made since Rav4-EV.

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 05:09 PM) [snapback]486342[/snapback]</div>

Oh I see the reason our numbers are different. Your numbers are how much it will cost Toyota but not us. I got $2,150 from the price we can purchase. After all, we are consumer of these cars but not manufacturers.

<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 05:09 PM) [snapback]486342[/snapback]</div>

I want to see HCCI (or a hybrid of HCCI and Spark Ignition) engine in HSD. I was hoping for next gen but it seems unlikely.


<div class='quotetop'>QUOTE(jhinton @ Jul 27 2007, 05:09 PM) [snapback]486342[/snapback]</div>

Very good. It will not be realistic or even dangerous for a car. There can be unlimited torque but without power, the acceleration will be limited.

 

<div class='quotetop'>QUOTE(darelldd @ Jul 27 2007, 05:36 PM) [snapback]486358[/snapback]</div>

I guess I mixed them up. I just googled up and found the pack to cost $10k.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Jul 27 2007, 03:35 PM) [snapback]486292[/snapback]</div>

M1s are brand new technology, and haven't had the time to get down to the prices of standard lithium-ion. When they do (and there is no reason why they shouldn't once production is ramped up), they should meet the same (or lower) costs than today's typical 18650s.

See this independent review of the lithium-ion battery production costs:

http://www.transportation.anl.gov/pdfs/TA/149.pdf

The most useful information is summarised on page 34. It puts the cost of a single 18650 cell at $1.70. Assuming 8 Wh/cell, that's equivalent to $212 per kWh. Easily within PHEV / EV viability territory.

All we need is for manufacturing to ramp up. Supply and demand will sort this one out....

 

As for the Volt, I have less doubt than many on this board that they will somehow find a way to pull this off. I worry far less about GM's engineering capability than I do about what their accountants will do when they get hold of the car. Those people alone have ruined a lot of good ideas.

I would hope that they've learned their lesson over at GM. This is no time at all for them to deceive themselves.

As for the person who commented that the Volt exists to get the heat off of GM for their SUVs, do remember that the Prius hides a lot of Sequoias, Tundras, and other such things.

 

<div class='quotetop'>QUOTE(MaxLegroom @ Jul 31 2007, 12:40 AM) [snapback]487837[/snapback]</div>

Just like I said, the Prius is a marketing tool and Toyota has cashed in big time. I think the Volt will do just the opposite in the end at best. I'd put money on GM crossing their fingers that oil drops to $10 barrel and this will all go away. I think we're going into the low $90's before year end.