Can Aircraft Be Far Behind?

http://www.teslamotors.com/

Larry Dighera wrote:
http://www.teslamotors.com/

Well they say the motor weighs 70 pounds and produces 248 HP but I can't
find anything about the weight of the batteries.

On Tue, 9 Jan 2007 09:31:49 -0600, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in
:

Larry Dighera wrote:
http://www.teslamotors.com/

Well they say the motor weighs 70 pounds and produces 248 HP but I can't
find anything about the weight of the batteries.


Total weight is indicated as ~2,400 lbs (including air conditioning).
Given its 1:10 power to weight ratio, I'd say, if it had wings instead
of the beefy structure it requires to meet road safety standards, it
would fly. It wouldn't require any fuel. Recharges fully in 3.5
hours. I wonder if noise attenuating headsets would be necessary.

Larry Dighera wrote:

"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote:

Larry Dighera wrote:

http://www.teslamotors.com/

Well they say the motor weighs 70 pounds and produces 248 HP but I can't
find anything about the weight of the batteries.

Total weight is indicated as ~2,400 lbs (including air conditioning).
Given its 1:10 power to weight ratio, I'd say, if it had wings instead
of the beefy structure it requires to meet road safety standards, it
would fly. It wouldn't require any fuel. Recharges fully in 3.5
hours.

The batteries weigh 900 lb., and put out 75 HP for an hour. You wouldn't
get too far on that in a C150.

On Tue, 09 Jan 2007 10:19:00 -0600, James Robinson
wrote in :

Larry Dighera wrote:

"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote:

Larry Dighera wrote:

http://www.teslamotors.com/

Well they say the motor weighs 70 pounds and produces 248 HP but I can't
find anything about the weight of the batteries.

Total weight is indicated as ~2,400 lbs (including air conditioning).
Given its 1:10 power to weight ratio, I'd say, if it had wings instead
of the beefy structure it requires to meet road safety standards, it
would fly. It wouldn't require any fuel. Recharges fully in 3.5
hours.

The batteries weigh 900 lb., and put out 75 HP for an hour.

I didn't see those numbers on the Tesla Motors web site. Have you got
a source for that information? There is a chart here, but it is more
about marketing than engineering:
http://www.teslamotors.com/performance/performance.php

Your numbers seem to conflict to some degree with these:

http://en.wikipedia.org/wiki/Tesla_Roadster#Battery
Battery:
6,831 Lithium ion battery cells
About 450 kg
Full-charge time of three and a half hours
~56 kWh capacity

If an aircraft were covered in Spectrolab* triple-junction solar
cells, fuel would be free during the daylight, quiet, and pollution
free.

You wouldn't get too far on that in a C150.

With a C-150 gross weight of ~1,600 lbs, it's considerably lighter
than the Tesla Roadster. But an aircraft wouldn't require many of the
car's systems such a transmission, electric windows, heavy running
gear (springs, 17" wheels and tires, disk brakes, power assist
steering, etc), and the Tesla motor weighs less than 70 lbs. What is
the weight of the Continental O-200 complete with its manifolding,
muffler, oil, and fuel?

Intuitively, an electrically powered aircraft employing Li battery
technology still seems feasible to me.


And, this fellow seems to have his finger in the pulse of the electric
propulsion issue:

http://www.wired.com/news/wiredmag/0...l?tw=rss.index
Tesla has managed to produce an impractical and exorbitantly
expensive vehicle just as a revolutionary new battery has appeared
on the scene. The question is whether Tesla Company will screw its
initial owners by delivering the car with its obsolete lithium ion
laptop batteries (all 6831 of them), a more clumsy way of powering
an electric vehicle than I've ever seen. I really don't think big
oil is shaking in its boots at the appearance of a $90K two seater
that has a range of 250 miles and takes 4 hours to recharge.

The Tesla as it stands is obsolete if it doesn't use the new type
batteries from Altair[**]. It will be the laughingstock of the
business world if it delivers its current overly-complicated
battery system, with its computers and sensors and HVAC system.
Tesla has discovered that the best laid plans can be shattered
when the unexpected happens. Yet the new batteries have been known
about for months. Now they've been demoed in Sacramento in an SUV
and can be recharged in 8 minutes, flow 4 times the power of those
Tesla is using, operate in temperatures where Tesla's cannot and
can be recharged 15 times as many times as Tesla's. They are
intrisically safe and don't require all the computerized
paraphernalia the Tesla contains.

Now we'll find out whether the Tesla company is on the ball. As it
now is, the Tesla car isn't worth a damn with those obsolete
lithium ion batteries, which cost $20,000+ and last a paltry 4-5
years.


* http://www.spectrolab.com/prd/terres/tasc-main.htm

** http://www.marketwire.com/mw/release...lease_id=83895

http://www.b2i.us/profiles/investor/...Cat egory=856

Recently, Larry Dighera posted:

On Tue, 09 Jan 2007 10:19:00 -0600, James Robinson
wrote in :

Larry Dighera wrote:

"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote:

Larry Dighera wrote:

http://www.teslamotors.com/

Well they say the motor weighs 70 pounds and produces 248 HP but I
can't find anything about the weight of the batteries.

Total weight is indicated as ~2,400 lbs (including air
conditioning). Given its 1:10 power to weight ratio, I'd say, if it
had wings instead of the beefy structure it requires to meet road
safety standards, it would fly. It wouldn't require any fuel.
Recharges fully in 3.5 hours.

The batteries weigh 900 lb., and put out 75 HP for an hour.

I didn't see those numbers on the Tesla Motors web site. Have you got
a source for that information? There is a chart here, but it is more
about marketing than engineering:
http://www.teslamotors.com/performance/performance.php

Your numbers seem to conflict to some degree with these:

http://en.wikipedia.org/wiki/Tesla_Roadster#Battery
Battery:
6,831 Lithium ion battery cells
About 450 kg
Full-charge time of three and a half hours
~56 kWh capacity

I don't have my hp W tables handy... if you do, how does Robinson's info
conflict, given that the weight is about right as "about 450 kg" ~= 990
lbs.

Intuitively, an electrically powered aircraft employing Li battery
technology still seems feasible to me.

The possibility isn't the question; what would it take?

And, this fellow seems to have his finger in the pulse of the electric
propulsion issue:

The reference is very interesting, yet I think this writer is off-target
in his critical focus on the Tesla. Would he pay $90k if it had the Altair
battery instead?

While the Altair battery offers some theoretical advantages over the Tesla
power pack, neither is a complete solution. The Altair battery's basic
configuration is 13v. @ 88 Ah.
http://www.altairnano.com/markets_amps.html

That isn't a very long drive in an electric-only vehicle. However, in a
hybrid there are potential advantages because it can be charged rapidly.
Unfortunately, it can also be discharged rapidly which can be a
significant hazard. In short, I'm intrigued, and I think that there may be
a future for PLI batteries. Additionally, the original Marketwire article
makes it seem that there is reason to be cautious about optimistic
predictions for this company, so perhaps the "bird in the hand" is the
best approach for Tesla, whether or not they can deliver on the
performance.

Neil

Larry Dighera wrote:
If an aircraft were covered in Spectrolab* triple-junction solar
cells, fuel would be free during the daylight, quiet, and pollution
free.

You get something like 1 kW/m^2 of energy from the sun under good
conditions, like being on the equator on a clear day in the summer. I
think current PV cells are somewhere around 10% to 15% efficient, so
that's 100-150 watts per square meter. Google says a Cessna 182 has
about 16.2 m^2 of wing area, so you might get around 1.6-2.4 kW from
solar cells covering the wings. You'd get a little more from the rest
of the skin, but IMHO probably not more than 50% additional, or 2.4
to 3.6 kW. That's 3.2 to 4.8 hp that the cells are contributing.

Also, does the solar cell factory run on solar cells?

What is the weight of the Continental O-200 complete with its
manifolding, muffler, oil, and fuel?

http://en.wikipedia.org/wiki/Continental_O-200 says about 170 lbs (77
kg) dry for just the engine.

For an electric drive, in addition to the weight of the motor and
batteries, you'll also need to figure in the weight of the inverter
that changes DC into three-phase AC. Some of these inverters are
air-cooled and some are liquid-cooled.

http://www.wired.com/news/wiredmag/0...l?tw=rss.index
Tesla has managed to produce an impractical and exorbitantly
expensive vehicle just as a revolutionary new battery has appeared
on the scene.

I've only been involved in hybrid cars for about six years, but I've
already seen a few "revolutionary new batteries" come and go. Many of
these batteries turn out to be quite good at ensuring a steady flow of
press releases out and money in, but never quite manage to push any
actual electrons.

Matt Roberds

Larry Dighera wrote:

On Tue, 09 Jan 2007 10:19:00 -0600, James Robinson
wrote in :

Larry Dighera wrote:

"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote:

Larry Dighera wrote:

http://www.teslamotors.com/

Well they say the motor weighs 70 pounds and produces 248 HP but I
can't find anything about the weight of the batteries.

Total weight is indicated as ~2,400 lbs (including air
conditioning). Given its 1:10 power to weight ratio, I'd say, if it
had wings instead of the beefy structure it requires to meet road
safety standards, it would fly. It wouldn't require any fuel.
Recharges fully in 3.5 hours.

The batteries weigh 900 lb., and put out 75 HP for an hour.

I didn't see those numbers on the Tesla Motors web site. Have you got
a source for that information? There is a chart here, but it is more
about marketing than engineering:
http://www.teslamotors.com/performance/performance.php

Your numbers seem to conflict to some degree with these:

http://en.wikipedia.org/wiki/Tesla_Roadster#Battery
Battery:
6,831 Lithium ion battery cells
About 450 kg
Full-charge time of three and a half hours
~56 kWh capacity

The conversion factor for kg to lb is 2.205, so 450 kg is 992.25 lb.
Therefore, it's actually closer to 1,000 lb. of batteries, according to
those specs.

The conversion factor for kWh to HP-hr is 1.34, so 56 kWh is the
equivalent of 75.04 HP-hr

Here is the page on the Tesla Motors web site that I found the comment
that the batteries weighed 900 lb.

http://www.teslamotors.com/blog1/ind...9&js_enabled=1

I found the 56 kWh number on another page, and simply converted it to
horsepower, since those are the units that most GA pilots would be
familiar with.

You wouldn't get too far on that in a C150.

With a C-150 gross weight of ~1,600 lbs, it's considerably lighter
than the Tesla Roadster. But an aircraft wouldn't require many of the
car's systems such a transmission, electric windows, heavy running
gear (springs, 17" wheels and tires, disk brakes, power assist
steering, etc), and the Tesla motor weighs less than 70 lbs. What is
the weight of the Continental O-200 complete with its manifolding,
muffler, oil, and fuel?

Well, let's look at some numbers. A gasoline aero engine of that size is
typically about 2 lb. per HP, so a 100 HP engine would weigh about 200
lb. I believe the O-235 is listed at 215 lb., with supplies, so it's in
the ballpark.

In comparison, three phase motors typically weigh about 1 lb. per
horsepower. That would mean a 100 hp motor would weigh about 100 lb. I
suspect that the Tesla's motor weighs less, because it is rated for less
continuous duty than would be necessary on an aircraft. An automobile
engine practically loafs along when on the highway at constant speed, and
only needs to have power for short bursts of speed. An aircraft engine,
on the other hand, operates at high power for hours on end.

The fuel and tanks would also be unnecessary with an electrically-powered
aircraft. A typical C-150 has something like a 26 gallon capacity. At 6
lb. per gallon, that would be 136 lb. Add roughly 20 percent to that to
account for the weight of the tanks, or 27 lb, for a total of about 165
lb. for the fuel plus the tanks. The grand total being 215 + 165 = 380
lb. Some additional amount could be added for fuel lines, filters and
pumps, but they would be relatively small. As a round number, lets say
everything weighs 400 lb.

So, if we take out the IC engine, and replace it with the batteries used
in the Tesla, and an appropriate electric motor, we would take out 400
lb., and add 900 plus 100 lb. for the batteries and motor, assuming the
ligher weight, plus some additional for the electrical control system an
wiring. Even without the control system, we would have a net gain in
weight of about 600 lb. Considering that a C150 has a usable capacity of
only 370 lb. or so with full fuel, The electically-powered aircraft would
already be more than 200 lb. overloaded, and we haven't even considered
the pilot, passenger, or baggage. Doesn't sound too practical, does it?

Larry Dighera wrote (rather quoted a comment from wired.com):
http://www.wired.com/news/wiredmag/0...l?tw=rss.index
The Tesla as it stands is obsolete if it doesn't use the new type
batteries from Altair[**]. It will be the laughingstock of the
business world if it delivers its current overly-complicated
battery system, with its computers and sensors and HVAC system.

Larry, just BTW, the Altair Nano batteries this guy is going on
don't pass the sniff test very well...

Tesla isn't using them because Tesla wants to ship cars
sometime this decade.

Altair claims that WRT conventional graphite electrode lithium-ion
batteries, their TiO nano-granule electrode lithium-ion batteries
have 3X the energy density, 60X the max charge rate, and 10X
the charge-cycle lifetime.

If these batteries actually existed in a form that would allow
Tesla to ship 200 cars this year, you would think that every
single cell phone and laptop in the universe would be running
on them, wouldn't you? I mean, *I* want my cell phone charge
to last 2 weeks instead of 5 days, *I* want to be able to charge
my laptop in 1 minute, and then have it last through an entire
8-hour flight, *I* want my cell phone battery to
last longer than the phone instead of having to replace the
battery after 18 months.

But yet I can't go to batteries.com and buy one of these
wonderful batteries that Tesla is so stupid for not using.
I think there *might* be a reason for that. :-)

BTW, this press release:
http://www.autobloggreen.com/2006/12...-phoenix-moto/

seems to indicate that Altair's entire production volume of batteries
to date is 10 35kWh battery packs for $750,000. It apparently
took 30 days (well, that includes Christmas) to deliver all 10 battery
packs.

I hope Altair and Phoenix are fabulously successful, but there is
good reason for skepticism.

-Jay-

James Robinson wrote:
The batteries weigh 900 lb., and put out 75 HP for an hour. You wouldn't
get too far on that in a C150.

you would save a noticeable amount of weight from not needing to carry
fuel (avgas is something like 6lbs per galon, so that would be approx
300lbs "offset" (not saved, but shifted to battery cell weight)
also, no oil (so thats a few more pounds)
and electric motors are fairly light compared to internal combustion
blocks


it would seem that powered gliders would benefit the most from this
tech because of their larger wingspan, mostly daylight operations (so
solar power), and they could probably recharge a little by spinning a
turbine when using airbrakes or something
(not a glider student and not an electircal engineer, so not really
sure about how useful this would actually be)