Technocrat

Another Electric Sportscar Entry

zogger
Sat Jul 26 18:22:00 -0700 2008
Mechanics
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Shown at the British Motor Show recently, the Lightning is a high performance electric sportscar with features like motors in the wheels and the new Altairnano battery system, which they claim outperforms other lithium battery systems, many more charge cycles possible, wider normal heat range in useful service, etc. That's their plan anyway, they are reserving orders based on theoretical specs. Price appears to be in the if you have to ask, you can't afford it range.

ed.z.: At least it is getting to the point a variety of builders are taking electric cars seriously, and I can't really blame them shooting for the high end market first seeing as how all the first runs will be more or less custom built units. With that said, I like Andy Groves idea of a huge number of new garage "electric car whitebox shops" to do truck and suv and regular car conversions. None of them will be high performance, obviously the regular heavy steel frame vehicles will just be...well, heavy.. but perhaps a bit more affordable for the regular working guy. Who knows right now, I imagine though, like I said before, the Chinese and Indian manufacturers will have the most models at the opposite low end for sale in any quantities. And probably pretty soon, I don't think it takes them ten years to come out with new models, I think more like 10 weeks to months, tops, especoally for electric if they really want to. I did a JE last week or so commenting on a potential DIY NEV hybrid you could build right now at Home Depot, well, at least my local one you could. They have a little electric two seater pickup for five thousand bucks, you go down the aisle to the generators and they have a 13.5 KW model for $1100. And there ya go, 6100 dollars for a do it yourself hybrid in the small category, so I will guesstimate doubling those costs would get you pretty close to a "normal" sized small regular electric vehicle with good enough range and performance to serve as a 30-40 miles range electric commuter car, using off the shelf non exotic stuff you can get right now, then have the option of making it a hybrid trip machine by throwing the generator in the back, clamping it down and plugging it in, or putting it in a small trailer, like those small ones the landscape boys use. *Guesstimate* but you see that electric buggy and it sure looks closer to a real vehicle than not. I know if it was legal I'd drive the thing into town and go shopping with it, it's bigger than the Fiat I used to own, and it sure would carry more weight in the back.

Another Electric Sportscar Entry
Bhima
Sun Jul 27 00:39:07 -0700 2008
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I don't think it is all that helpful to look at the current offerings at a home improvement shop to get an idea of what is possible with the current state of the art of electric passenger vehicles.  What makes the electric commuter vehicle or even the electric sports car doable are battery technologies which have dramatically higher energy densities than the old lead acid battery, electric motor technologies which are more efficient than the common DC motor, DC/AC traction motor inverter / control technologies which exceed 90% efficiency ratings (and provide features like regenerative breaking and reverse gear).

Using state of the art components will make for a more expensive vehicle but surely a more useful one.

As a side note, I have been watching Tesla transmission development with interest.  My understanding is that transmissions are currently the least optimal design most often retained in electric vehicle conversion.  So the availability of a purpose designed 2 or 3 speed sequential manual transmission specifically for electric commuter vehicles is one of my triggers that it is time to buy or convert one.

Another Electric Sportscar Entry
Michael Smith
Sun Jul 27 01:19:56 -0700 2008
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As a side note, I have been watching Tesla transmission development with interest.  My understanding is that transmissions are currently the least optimal design most often retained in electric vehicle conversion.  So the availability of a purpose designed 2 or 3 speed sequential manual transmission specifically for electric commuter vehicles is one of my triggers that it is time to buy or convert one.

I could be wrong but the impression I had was that the two speed transmission in the Tesla is there to ensure that takeoff speed and maximum speed are both reasonably close to the very broad torque peak of the traction motor. If you don't want to get to 200km/h then I don't think you need a transmission at all.

It should be possible though to build motors which peak at different speeds. For a car like this one with motors in the wheels I wonder if you could (say) design the motors in the back wheels to peak at 60 km/h and the motors in the front wheels peak at 100 km/h. Shifting the load between front and back would give you the ability to follow the torque peak and four wheel drive is still available.

Another Electric Sportscar Entry
Bhima
Sun Jul 27 08:35:47 -0700 2008
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Good point... perusing the various build blogs I had come to the conclusion that most users had a "city gear" and a "freeway gear".  I am not so interested in another car which can cruise at 200 kp/h, as I am a car which handles the small city I live in well.

I haven't seen much on the in wheel hub motors but I don't see anything wrong with your idea.

Price ranges

zogger
Sun Jul 27 07:59:32 -0700 2008
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No doubt whatsoever there are much better ways to go about building an electric car, the in-wheel motors seem a reasonably good bet (no transmission at all needed then) along with a variety of battery technologies and extreme lightweight materials, etc, but all of that costs *serious* money. Any advanced lithium battery pack is running..well, it is a lot, multiple multiple thousands, and that's just for the batteries. The world market for new cars consists of tato nano prices to egadzooks! prices.

I was just looking at what is possible right now on the very cheap, the opposite end of Tesla level or above that. Nice to look at, I'll keep dreaming right now being a solid *dozenaire*. The little buggy I was looking at (really, a little truck, with a dump body!) used bog standard and cheap flooded lead acid batteries and claimed an over 30 mile range, albeit at much slower speeds, it isn't road worthy at highway speeds at all and could only even theoretically be legal as a neighborhood electric vehicle where you are limited to roads with posted 35 MPH limits or lower. Call it between a standard golf cart and what could be a "real" vehicle. I was just musing at around double that cost it would be "good enough" probably to do most roads below the highway speeds and actually turn the corner to be an entry level practical little vehicle then.

The car market is big, however, and not everyone can afford a 40 to 100 thousand dollar electric car right now, in fact, the car companies in the US are having a tough time moving those sorts of expensive beasts, whereas at roughly around half that entry level price, in the 20 grand level, they are selling briskly, so any electric commuter car will need to hit around there at least as a starting point. I think a 40 grand electric car could sell now, but it would have to be pretty slick. Make it an extreme plug in hybrid with only a minimal single cylinder ICE just for accessories and heat and A/C and I think you could do it. Perhaps. The Prius is at 25 with a waiting list right now, for our closest mainstream mass numbers example, and it isn't even plug in hybrid yet. You can make it a plugin by losing the trunk and adding around ten grand or so of extra batteries. That is pretty close to 40 grand, but you lose the trunk then. Take the bigger ICE out though, you lose weight and gain space. Tradeoffs. Do you want a commuter car, or a car you can drive anyplace, anytime, any distance?? The price and complexity differential there is huge, unless you go to the trailer generator model, then it isn't so bad theoretically because you could rent those things for the occasional long distance trip.

And there is another costing point, a cheaper pure electric using non exotic anything doesn't need the expense of the ICE part (outside of the accessories like I offered), if it is sold upfront as a slower speed, limited range runabout/close in commuter. Tell the people upfront exactly what they are getting. Baby steps and mass quantities to get prices down better with economies of scale. Along with simple. In other words, we need the electric version of the VW beetle for something beyond what the richer guys could afford, with the simplest option for the same basic car being how much you want to pay for a battery pack, cheap lead acid comes standard, more for NiMH, then on to exotic lithium-whatevers. I could see people buying the initial car with the cheapest battery pack, then once it is paid off, upgrading a step or two with the now freed up cash they would have, offer the same sort of financing. One of the big points with electrics is they should last, we should start seeing cars that just don't break as much and not be near as complex. Along with upgradable battery pack systems, with in-wheel motors, the engine could be upgraded pretty fast as well. Want more beef, swap the wheels, trade in the old ones, get new higher performance ones, etc.

Price ranges
Bhima
Sun Jul 27 09:13:08 -0700 2008
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Battery prices are falling pretty quickly... I think just idly rolling around a plan which won't be put into action for many months or even years and you can think about technologies you can't afford today.  Just googling around for electrified Chevy S-10s shows successful conversion costing from $6-9K USD and claimed ranges from 40-100.  However they all pretty much consume the truck's payload capacity... which is a bummer but having having a short range virtually maintenance free vehicle does have some merit.  To me having something that is say $3-5k more and is more drivable & usable makes more sense.  Add another few K and it probably makes my electric Z4 as a commuter idea possible.

Also some of the higher tech items can be thought of as paying for themselves... a state of the art battery charger extends the life of the battery pack, saving you more than a few multiples of the cost of the charger.

Others make the vehicle more useful.  A newer tech battery pack would be smaller & lighter than lead acid pack of the same capacity.  Using the S-10 as an example you get back most of your cargo space and some capacity.  Modern DC-AC inverters are more efficient and provide regenerative breaking so to attain the same range you need less weight in batteries.

I am not a big fan of hybrids.  I think that they are twice as complicated for less than twice the efficiency gains.  So I really don't get the idea of having a single cylinder to drive the accessories.  At this point there are electric alternatives or electric pumps to everything found on cars:  Electric assisted steering, electric vacuum pumps for the old vacuum boosters for break assist, electric AC compressors, electric water heaters (for nearly instant defrost and heating).  I expect by 2010 you'll be able to get aftermarket electric everything

Oh... and don't forget if you change the traction battery pack chemistry, you also need to change the charger, possibly the controller and other circuitry in the vehicle.  That would get pretty expensive.

 

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