What a Joke!

[chesspirate]

http://autoshow.autos.msn.com/autoshow/detroit2007/Article.aspx?cp-documentid=1692328
Do they really expect us to believe this is hard to do?

[TomO]

Quoted from Video about the Volt= "I am shocked, truly shocked" <chuckle> being shocked by an electric vehicle....I wonder how that feels. and I hope that those gawd awful 20some inch wheels are light as H-E-double hockey sticks because that is a big waste of the cars electricity.

But seriously, they could've used a small diesel motor instead and probably saved even more on resources. Plus that range of 40 miles on pure li-ion pack sounds bogus, unless that is a small pack by EV standards.

[JanGeo]

Cars usually need about 1KWH per 5 miles so a 20KWH battery pack would be needed to go 40 miles. I just noticed that there is almost no travel room for the tires into the fenders and if the front wheels are turned . . . even less. 2777 Lithium cells weighting 444 lbs would be about a 20kwh battery pack and cost about $7000 with current pricing.

[cfg83]

Hello -

At first I was about to bash this car too, but I read some more and I think it is ok. I don't like the design, but I don't hate it either. Here are some more details :

http://www.edmunds.com/insideline/do/Features/articleId=119088

I always try to figure out what they were thinking. Chop top look that is justified by smaller frontal surface area. Loss of top leads to "sunken" side windows. Small commuter, maybe trying to take advantage of Pontiac Solstice aesthetic?

Keep in mind one thing about the 40 mile range. That is true if it is 100% electric mode. The small "powerplant" engine is used to extend the range. As electric batteries improve (or when Chevron gives up the patent), this car could be retooled as a 100% electric.

That said, GM will always be public enemy #1 for foisting the Hummer on us.

CarloSW2

[TomO]

It states that the vehicle has a total range of 640 miles. It also states that it can go 40 miles on pure electricity mode. That leaves 600 miles on 12 gallons of gas (stated gasoline capacity), 600/12 = 50 mpg. That is if you drive the thing non-stop. It'd probably work out to more MPG given the fact that most people only commute a total of 40 miles daily and would recharge the battery via 110V house electricity.

This kind of brings up a question in my mind; If you can drive this thing without ever firing the ICE, how long would the gas stay good? I've heard stories of gasoline being exposed to air for 30 days becoming lower in octane.

[JanGeo]

Todays gas is good for maybe 3 months before it separates into unburnable junk. I always wondered about that though because it seems that my MPG drops as the gas gets lower in the tank if I don't burn it up fast enough - like typically I go about 3 weeks. I start off in the mid 40's and then struggle to get 40 towards the end of the tank.

[MetroMPG]

When I test drove the Blackfly, it had half a tank of seven year old gas in it. Started right up. Drove fine.

Though I'd probably put fuel stabilizer in it if I knew I was going to park it for a long time.

[thisisntjared]

its funny that that cars system pretty much makes the electricity cost the same as gas....

very close cent per mile to the currently economy vehicles.

[chesspirate]

... That leaves 600 miles on 12 gallons of gas (stated gasoline capacity), 600/12 = 50 mpg. That is if you drive the thing non-stop. It'd probably work out to more MPG given the fact that most people only commute a total of 40 miles daily and would recharge the battery via 110V house electricity.
This almost makes me hate this car a little less... BUT, why should i be excited about 50mpg from an electric car? I thought the point of electric was to not have to burn gas? (at least pump gas) I think this is just another way of packaging something to look better than it really is. Not to mention we've got guys on here beating 50mpg with home-made, old-school, modified, gear head tech. Shouldn't the big guys be able to produce somethign a little bit better?

[MetroMPG]

I think the point of the Volt concept is that if you drive less than 40 miles a day (like, apparently, the vast majority of Americans), you'll hardly ever have to buy gas. You'll only need to fuel up for longer trips.

[cfg83]

Hello -

Here I am defending GM again, go figure. I don't think of the Volt as a pure electric. It is a hybrid with a flexible drivetrain model. If the batteries get better, the all electric range goes up. If clean diesels make a splash in the US, it could have really great MPG. Notice this :

... General Motors has unveiled the Chevrolet Volt concept, the company's first plug-in hybrid vehicle, at the 2007 North American International Auto Show in Detroit ...

This is the "plug-in Prius" engineering model that the Prius "Electro-gearheads" have already proven can net 100 MPG.

However, from what I have read, Toyota will beat them to it and make a plug-in Prius before the Volt sees the lightbulbs of American car showrooms.

It definitely ain't the next EV1.

CarloSW2

[JanGeo]

I think the point is that it IS an all electric vehicle with an on board generator and NOT a series or parallel hybrid. Thus it is flexible in that any power source could provide the long range electric energy. Imagine an option of purchasing it without the ice.

[omgwtfbyobbq]

Your the owner's choice of battery capacity/ICE size? How could would doubling the EV range, and quartering the generator output for the same price be?

[JanGeo]

Well it would mean half the constant speed of 70mph if 1/4 the power ICE after 2 x 80 miles if traveling at 70mph since the 70mph speed was at 50% ice run time. If you were traveling at a lower speed then you could travel even further before you would have to slow down.

[omgwtfbyobbq]

It may be easier. Just allow the genset to rev higher and make more power, even if BSFC drops. I mean, I'd rather have a genset tuned for minimal BSFC at 55-60mph, the ability to make enough power to go 70-80mph, and more batteries, compared to something masquerading as a "performance" automobile.

[JanGeo]

You may not have that option - usually you ARE running at Peak Power if you are using a 1/4 HP rated generator - then again how often do you travel that far without slowing down. You can't have it both ways! Pushing the generator harder shortens its life, puts more demand on the fuel usage and creates more heat. That is the point of having one big enough to do the job - don't start falling into the American Car rut Need more power to Move more iron to burn more gas vicious circle.

On the other hand in the Winter time running an ICE to create some heat would be a good idea. My xB, now that it is that much more efficient, barely keeps me warm and if I crank up the heater fan the engine temp drops even while driving.

[The Toecutter]

Cars usually need about 1KWH per 5 miles so a 20KWH battery pack would be needed to go 40 miles. I just noticed that there is almost no travel room for the tires into the fenders and if the front wheels are turned . . . even less. 2777 Lithium cells weighting 444 lbs would be about a 20kwh battery pack and cost about $7000 with current pricing.

At 1 kWh every 5 miles, that would be an 8 kWh pack for 40 miles range, not a 20 kWh one. A 20 kWh pack would send it 100 miles at .2 kWh/mile. This 8 kWh pack would weigh ~180 lbs.

[omgwtfbyobbq]

You may not have that option - usually you ARE running at Peak Power if you are using a 1/4 HP rated generator - then again how often do you travel that far without slowing down. You can't have it both ways!

I can if I'm not going to cruise down the freeway at 70mph. ;) I don't mind putting around at 55mph, so if I can save money on the genset and add more batteries, while having the same or better efficiency at 55mph, even if I don't get the same efficiency at 70mph because the smaller genset needs to spin at 3,000+rpm, I wouldn't mind. I'd have farther all electric range, and a bigger battery buffer for the need to climb hills/accelerate quickly, and get the same or better mileage at the speeds I normally travel.

[JanGeo]

At 1 kWh every 5 miles, that would be an 8 kWh pack for 40 miles range, not a 20 kWh one. A 20 kWh pack would send it 100 miles at .2 kWh/mile. This 8 kWh pack would weigh ~180 lbs.

RIGHT - back to school for me - but factor in some DOD so they last more than 300 cycles and enough cells to output the peak watts.

I keep thinking about EEStor and their 15kwh cap pack and how that would take me 450-500 miles on my scooter with the same weight that I have now with the lead batteries . . .

[The Toecutter]

Current 18650 size Li Ions just aren't suitable for PHEVs. Even if you get 2,000 cycles out at 50% DoD for a pack that goes 40 miles at that percentage discharge, that's only 80,000 miles like. For 40 miles range at 50% discharge, now there's the 16 kWh pack, at $700/kWh, that's $11,200. For only 80,000 miles life, that's a huge operating cost.

Altairnanobatteries could really change this dramatically.

However, for a pure BEV with 250 miles range, a 500 cycle to 100% DoD, 50 kWh Li Ion pack is much more viable. Worst case scenario is 125,000 miles pack life, but in theory, assuming 2,000 cycles at 50% discharge, that's 250,000 miles pack life(not factoring in shelf life). Most people don;t drive 125 miles a day, so it would last a bit longer(in theory, but shelf life isn't factored).



In automotive volume, Li Ion would be $250/kWh, which would make both concepts cost effective. However, the pure BEV would be much more viable to consumers due to its pack life. You don't want to be replacing a pack during the vehicle's lifetime unless it is at most a few thousand dollars.

GM is pursuing one of the worst routes for a vehicle with this PHEV. If it wants to do a PHEV, it should be using Ovonic NiMH, which has much longer cycle life at deep discharge than 18650 size Li Ion. For 18650 size Li Ion, a pure EV is a much better fit, and is viable.

Or better yet, use Altairnano batteries if the technology really meets the hype.

[JanGeo]

You can't get the power and weight density with NiMh and they are going to cost you about 25kwh more to charge than the 50kwh you get out of them from charging losses and that ends up costing a lot in the long run. Conventional LiIon cells do have a calender life that will kill their use - I am currently evaluating a few hundred dollars worth right now because I can't seem to get enough time to build them into a EV to actually use them. Building a 50kwh pack would require about 7000 cells and I have enough trouble dealing with 70 cells. Even AltairNano has no large cell design - same problem for all Lithium cell construction - except for MIT Sadoway. Looks like the gold solution is going to be the new EEStor ultra caps with a cost about the same as Lead batteries and high power output. If they are as good as I think they are going to be, you could even add more packs for longer range and then take them out for less weight shorter trips without a power penalty because they put out so much power.

[The Toecutter]

You can't get the power and weight density with NiMh

This can be compensated for with the right chassis design. The EV1 was able to fit about 1,147 pounds of NiMH which allowed about 150 kW of peak power from the battery side. Fitting a 500 lb pack into a PHEV is not out of the realm of possibility.

and they are going to cost you about 25kwh more to charge than the 50kwh you get out of them from charging losses and that ends up costing a lot in the long run.

Yeah. Their charge efficiency isn't the greatest, but the cost per mile of Li Ions is usually going to outweigh the cost of the additional energy use from charging the NiMH.

Conventional LiIon cells do have a calender life that will kill their use - I am currently evaluating a few hundred dollars worth right now because I can't seem to get enough time to build them into a EV to actually use them.

Unless you have a way to keep them cool while they are operating, I doubt they will last more than 5 years to 80% capacity. Otherwise, I'd expect them to lose about 2% per year. Please share your data when you are done experimenting! :)

Building a 50kwh pack would require about 7000 cells and I have enough trouble dealing with 70 cells.

About what the TZero and Tesla are using!

Looks like the gold solution is going to be the new EEStor ultra caps with a cost about the same as Lead batteries and high power output. If they are as good as I think they are going to be, you could even add more packs for longer range and then take them out for less weight shorter trips without a power penalty because they put out so much power.

A controller to drive a motor off of those things is going to be a nightmare to build. Recently, their claims have seemed to be more credible than I originally found them, but I'm not going to hold my breath waiting for them either.

[JanGeo]

Ideally the EEStor caps at 300 volts charge would work well in the typical EV including the Prius as they are operating in that voltage range (285-290 volts Peak). Higher voltages will require down converters using some higher voltage semiconductors and probably are not going to be practical because of the charging issues - since 220 AC volts peaks at 360 volts when used to charge caps. Recent article seems in indicate that EEStor is capable of producing everything they claim and more as they tend to only announce proven products - they are engineers not sales/marketing people so they tell the truth. Apparently the ultracap construction process can produce very high voltage caps in the 1,200 to 3,500 volts range and possibly much higher by adjusting the insulating properties of the barium-titanate powders forming the insulation between the plates.
Entire article:
http://tech.groups.yahoo.com/group/ETList/message/6810

[The Toecutter]

Wouldn't the cap voltage vary wildly with state of charge? I do believe that near 50% discharge, that 300V set of caps would be somewhere around 140-160V...

If the claims are indeed true, the next hurdle for these caps is to develop in mass production the proper control system to allow them to drive a motor over their entire charge range. You don't want the caps to be restricted to operating at only 80-100% SOC in an electric car. Developing such a controller, compared with overcoming earlier battery restraints that plagued us up until NiMH were used, is probably a very simple matter.

The Zilla controllers seem to be a good candidate, able to operate anywhere from 48V absolute minimum to over 400V absolute maximum(but are suitable for battery packs of 72V-348V nominal). Just don't let the caps get discharged too much, and when they're near empty, you won't be able to make use of their full power because of the controller's voltage constraints and current limit.

[JanGeo]

Yeah but by then you have used 3/4 of the energy that it contained and if you design the system to operate on a lower voltage and charge to a much higher voltage and switch it down it works. My 4 battery system charged to 60 volts and when drained was a little over 40 volts - it still ran fine just had lower top end speed.