EV Digest 6780
Topics covered in this issue include:
1) Re: Torque?
by Jeff Major <[EMAIL PROTECTED]>
2) Re: belly pan plastic
by "Kip C. Anderson" <[EMAIL PROTECTED]>
3) Re: Vehicle efficiency, wh/mile
by [EMAIL PROTECTED]
4) Re: Using Audio Capacitors for Dragsters
by Lee Hart <[EMAIL PROTECTED]>
5) Re: Vehicle efficiency, wh/mile
by [EMAIL PROTECTED]
6) Re: Vehicle efficiency, wh/mile
by Lee Hart <[EMAIL PROTECTED]>
7) Re: Vehicle efficiency, wh/mile
by Lee Hart <[EMAIL PROTECTED]>
8) Re: "Honey, I Shrunk the Tires"
by [EMAIL PROTECTED]
9) Re: Reality check, Re: Permanent magnet motor question
by Lee Hart <[EMAIL PROTECTED]>
10) Re: Using Audio Capacitors for Dragsters
by Jeff Major <[EMAIL PROTECTED]>
11) RE: "Honey, I Shrunk the Tires"
by "midiguy732" <[EMAIL PROTECTED]>
12) RE: belly pan plastic
by Mark Ward <[EMAIL PROTECTED]>
13) Re: Torque?
by "Marty Hewes" <[EMAIL PROTECTED]>
14) RE: belly pan plastic
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
15) Re: Vehicle efficiency, wh/mile
by GWMobile <[EMAIL PROTECTED]>
16) Does anyone know of a good steam car group?
by GWMobile <[EMAIL PROTECTED]>
17) Re: Using Audio Capacitors for Dragsters
by "Marty Hewes" <[EMAIL PROTECTED]>
18) Re: Vehicle efficiency, wh/mile
by "Timothy Balcer" <[EMAIL PROTECTED]>
19) RE: Does anyone know of a good steam car group?
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
20) RE: Vehicle efficiency, wh/mile
by Tim Humphrey <[EMAIL PROTECTED]>
21) Re: Orbitals vs. Optimas
by Steve <[EMAIL PROTECTED]>
22) Re: Using Audio Capacitors for Dragsters
by Jeff Major <[EMAIL PROTECTED]>
23) RE: Using Audio Capacitors for Dragsters
by Tim Humphrey <[EMAIL PROTECTED]>
24) Re: belly pan plastic
by Lee Hart <[EMAIL PROTECTED]>
25) Re: Does anyone know of a good steam car group?
by GWMobile <[EMAIL PROTECTED]>
26) Re: belly pan plastic
by "Al" <[EMAIL PROTECTED]>
27) Here are the calculations. (was: Using Audio Capacitors for
Dragsters)
by Bill Dube <[EMAIL PROTECTED]>
--- Begin Message ---
Hey Patrick,
You could put it on a dynamometer. Or do a draw bar
pull test. Strap the truck to a stationary object
with a force gague (or big spring scale) and floor it.
Assuming the tires don't spin, the force you read
times the rolling radius is the torque at the wheel.
The motor will put out this maximum torque from zero
to about 7000 RPM.
I have some test data from an EV1 motor. I thought
the S-10E used the same motor and control. But the
EV1 was rated at 100 KW and the S10E at 85 KW, so
there may be some control limit or something to
derate, possibly for longer battery range. My test
data for the EV1 motor showed a peak motor torque of
132 lb.ft.
Hope this helps.
Jeff
--- [EMAIL PROTECTED] wrote:
> Hi,
>
> I have a 1998 Chevy S10EV with an 85kW (114
> horsepower) three-phase, liquid
> cooled AC induction motor. How could I determine
> the torque?
>
> Thanks,
> Patrick
>
____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play
Sims Stories at Yahoo! Games.
http://sims.yahoo.com/
--- End Message ---
--- Begin Message ---
In a message dated 5/15/2007 9:56:23 PM Central Daylight Time,
[EMAIL PROTECTED] writes:
I would like to work on improving the aerodynamics of my truck. Of course
I
want to keep weight to a minimum.
I am considering LDPE, HDPE, and "Lexan" in say 3/32 or 1/8 thickness.
Lexan
is probably best at impact resistance. Not sure if low or high density
poly
would be a good choice as it costs less than Lexan. Thanks for any
comments.
Al
I'm a huge fan of ABS plastic for stuff like this. Aside from it's good
durability and low expense, it is relatively easy to work with. On straight
cuts, just score a deep line and *snap*. It is also fairly stiff, but
flexible and won't crack or shatter without high stress.
1/8" thick sheeting is going to be plenty impact resistant to all but stuff
like folding lawn chairs and truck tire carcasses in the roadway. I've used
it for belly pan material myself and it worked great.
- Kip
--- End Message ---
--- Begin Message ---
George> Its a forgotten small detail, but if everyone converted to EV's,
George> state and federal road taxes now applied to gasoline would have
George> to be added to the cost of electricity, boosting the electrical
George> cost/mile somewhat.
We won't need most of the interstate highway system, so delete the taxes
which are applied to its maintenance. Nobody will have more than about
100-mile range. ;-)
--
Skip Montanaro - [EMAIL PROTECTED] - http://www.webfast.com/~skip/
--- End Message ---
--- Begin Message ---
Jack Murray wrote:
Why would the controller be stepping down the voltage when you are
launching at full-throttle?
Because for the motor, voltage is proportional to RPM. At zero speed,
you apply zero volts (in theory). In practice, you apply a very low
voltage; just a few volts is enough.
But current is proportional to torque. At zero RPM, you are still
applying a high current, to make high torque, so the motor accelerates.
If you dared to switch a series motor straight to a battery, a) the
motor would try to instantly jump up to a high speed, b) it would try to
draw "infinite" current from the batteries to do it, dragging their
voltage down to something very low, c) something would melt, break, or
blow up.
I agree that the caps must have low resistance, there are many
high-capacity caps that are not designed for high-current and have high
resistance. I didn't look at the audio caps, but the 400F Ness caps I
mentioned have only 3.8Mohm.
Do you realize how low the internal resistance of batteries are? A 6v
golf cart battery has about 5 milliohms of resistance -- and that's for
its three 2v cells in series. An Optima has about 3 milliohms of
resistance -- and that's the total for six cells in series. Supercaps
generally give a resistance for just a single 2.3v cell.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Danny> One of the stated motivations has actually been that fuel taxes
Danny> are unfair because hybrid cars pay much less road tax than a
Danny> Hummer. No joke. They've actually said this.
Make it fair and multiply the distance driven by the GVWR of the car.
--
Skip Montanaro - [EMAIL PROTECTED] - http://www.webfast.com/~skip/
--- End Message ---
--- Begin Message ---
Danny Miller wrote:
There are already test projects to replace fuel taxes and/or toll roads
with either an odometer reading or much more likely a GPS system...
I fear this more "convenient" form of billing could quickly lead to it
becoming as complex as, and as much a scam as, a cell phone contract...
Also important is a closed "black box" system operated in your car is
extremely prone to privacy issues.
My concern with "solutions" like this is that they are generally bad for
the people and good for someone else (the government, and the companies
that get the monopoly on selling you these systems). We pay the costs,
but the benefits go to someone else.
I believe that it you added up all the costs/benefits of hybrid and
electric vehicles, the benefits would already exceed the costs due to
lost gasoline revenues (reduced oil imports, less air pollution, fewer
health problems, lighter vehicles so less wear on the roads, etc.) So,
these fuel tax replacement systems cost more than they're worth.
Read "Other Days, Other Eyes" by Bob Shaw. It's a science fiction story
about a humble little invention that seems innocuous enough, but that
gradually grows to produce a dystopian future where the government can
literally watch and record everything that everyone does.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Kaido Kert wrote:
While you are correct that Solar still has hard time paying off, your
weight numbers are based on silicon panels. Look at thin-film instead,
like PowerFilm ( http://www.powerfilmsolar.com/ ) which is pretty
available, and there are others.
The added weight is next to nothing, cost, however ..
If you're putting PV panels on a car, then you have serious surface area
limitations, but weight hardly matters. In this case, you want PV cells
with the highest energy per unit area. This generally means silicon
monocrystal cells, as used in spacecraft and solar raycers.
If you're putting PV panels on a building roof, then surface area is not
much of a problem. People use 2-3 times the area to get the same the
same amount of energy, in order to get a much lower price. Thin film and
amorphous cells excel in these applications.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
But I believe you are trading mileage for traction. A skinnier hard tire will
not be as good in the rain, a hard stop and hard cornering.
You can also remove bumpers and seatbelts to save weight and also improve
mileage.
via Treo
David Hrivnak
-----Original Message-----
From: "Mark Hanson" <[EMAIL PROTECTED]>
Subj: "Honey, I Shrunk the Tires"
Date: Wed May 16, 2007 9:35 am
Size: 1K
To: ev@listproc.sjsu.edu
HI,
I used the following formulae: Width x Aspect Ratio = Section Height
Section Height x 2 = Combined Section Height
Combined Section Height + Wheel Diameter = Tire Diameter
A 185/60R14 that's 185mm wide
is 185mm x .60 = 111mm (section height)
111mm x 2 = 222mm (combined)
222mm + 355.6mm(14") = 577.6mm or 22.74"
So I could find skinnier tires like P205's instead of P225's same diameter
for my Ford ranger (10% less width). Mileage went from 27mph to 18.5mph.
The Diesel Beetle went from 50mpg to 54 mpg hwy with a 10% surface area
reduction also.
My E-Porsche went from 30 miles range to 33 miles range so skinnier is
better (but for some goofy reason people put fat tires on cars).
Have a Renewable energy day
Stoip by the lA Wind Expo June 3-6
Mark in Roanoke, VA
_________________________________________________________________
Catch suspicious messages before you open themwith Windows Live Hotmail.
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_protection_0507
--- End Message ---
--- Begin Message ---
jerryd wrote:
While I like PM motors for the reasons you
state, you didn't mention the bad points much.
They may make 35hp peak but if run for more
than a sec or 2, they burn up as they have no mass to absorb
the heat.
That depends on the motor, Jerry. If you're comparing a high efficiency
lightweight design like the Lynch/Lemco/Etek motors to a standard old
GE/Prestolite/ADC series motor, you're correct -- The PM design is 1/3rd
the weight, so it heats up 3 times faster under overload conditions.
But there are also large numbers of PM motors built pretty much just
like the old series motors, but with permanent magnets instead of wound
field coils. They have the same overload characteristics, and can handle
similar peak powers for similar times.
But you still have the usual PM motor tradeoffs. The PM motor is more
efficient at rated load (no field power losses). But at light load, it
is less efficient (because you still have full field strength, thus full
eddy and hysteresis magnetic losses). And at high peak loads, you risk
demagnetizing the magnets either from excessive current or excessive
temperature.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I have tested a lot of Optimas and never saw anything
close to 3 milliOhms. Always much higher. On the
other hand, when testing Maxwell ultracaps, the
resistance is lower than spec. Tested on a 9 pack of
2600 Farad cells (22.5 volts) was 4 milliOhms and did
not change much with temperature or state of charge.
The 9 cell pack weighed 14 pounds. Optima about 40
pounds. Hence a much better power density for the
cap.
Jeff
--- Lee Hart <[EMAIL PROTECTED]> wrote:
> Jack Murray wrote:
> > Why would the controller be stepping down the
> voltage when you are
> > launching at full-throttle?
>
> Because for the motor, voltage is proportional to
> RPM. At zero speed,
> you apply zero volts (in theory). In practice, you
> apply a very low
> voltage; just a few volts is enough.
>
> But current is proportional to torque. At zero RPM,
> you are still
> applying a high current, to make high torque, so the
> motor accelerates.
>
> If you dared to switch a series motor straight to a
> battery, a) the
> motor would try to instantly jump up to a high
> speed, b) it would try to
> draw "infinite" current from the batteries to do it,
> dragging their
> voltage down to something very low, c) something
> would melt, break, or
> blow up.
>
> > I agree that the caps must have low resistance,
> there are many
> > high-capacity caps that are not designed for
> high-current and have high
> > resistance. I didn't look at the audio caps, but
> the 400F Ness caps I
> > mentioned have only 3.8Mohm.
>
> Do you realize how low the internal resistance of
> batteries are? A 6v
> golf cart battery has about 5 milliohms of
> resistance -- and that's for
> its three 2v cells in series. An Optima has about 3
> milliohms of
> resistance -- and that's the total for six cells in
> series. Supercaps
> generally give a resistance for just a single 2.3v
> cell.
>
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in -- Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377,
> leeahart_at_earthlink.net
>
>
____________________________________________________________________________________
Get your own web address.
Have a HUGE year through Yahoo! Small Business.
http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
--- End Message ---
--- Begin Message ---
You are correct, and tire selection should be based on the primary
purpose of the vehicle.
For example, my F350 crewcab has tall, skinny tires with 80psi in them.
It's designed to haul 4000lbs in the bed or be hitched to a max of about
20,000 lbs. It's not designed to play with Corvettes, Vipers and
Porches.
The same applies to EV's. If you're building a utilitarian vehicle
that's designed to maximize range, and get you and your stuff from A to
B, then skinnier, harder tires are best. You're probably not going to
be taking exit ramps at 80 mph in such a thing anyway.
If you're building a "corner carver" or an electric track car, well,
then you don't want skinnies - and instead you want the size the tires
for the maximum contact patch you can utilized based on the vehicle
weight, size, and typical terrain.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
> Behalf Of [EMAIL PROTECTED]
> Sent: Wednesday, May 16, 2007 10:55 AM
> To: ev@listproc.sjsu.edu
> Subject: Re: "Honey, I Shrunk the Tires"
>
> But I believe you are trading mileage for traction. A skinnier hard
tire
> will not be as good in the rain, a hard stop and hard cornering.
>
> You can also remove bumpers and seatbelts to save weight and also
improve
> mileage.
--- End Message ---
--- Begin Message ---
I am going to use a large sheet of black pvc. It is tough, cheap and easy to
install with push-pins so you can remove it later. Use injectible foam to fill
any gaps as needed and hit it with paint. Works for me.
Mark Ward
95 Saab 900SE "Saabrina"
www.saabrina.blogspot.com
---- "Dewey wrote:
> What is wrong with using Aluminum? A 4x8 sheet of 18 gage aluminum is
> cheap. You could also bend it around obstructions or form it where it
> needed to be. It is light and will not crack or deform when exposed to
> oils. You can also put in small openings for venting if needed.
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Jeff Shanab
> Sent: Wednesday, May 16, 2007 9:14
> To: Electric Vehicle Discussion List
> Subject: Re: belly pan plastic
>
> I am gonna disagree on your comparison between lexan and acrylic, But it
> depends on the grade of each. In most cases, you have them interchanged.
> You are correct in it being a bad choice. Lexan gets damaged by
> oils.(actually it causes it to get brittle). Race cars use lexan
> windshields, bullet proof windows are sometimes lexan. Safety glasses
> are lexan. Both are inapproriate for a belly pan anyway.
>
> I have used the UHMW sheets to line the ramps for parts (from injection
> molding). The parts hit it from a few feet distance and the ramp liners
> lasted a long time.
>
> One more material is available from places like Precision Plastics or
> your local equivilant. The trade name is something like Vivek.
>
> Vivek is PTEG, the material used in 2 liter bottles. It is very tough
> and optically clear, UV stabilized, and is available in .062,.093,.125
> thick 4x8 foot sheets. If you want clear, This is the way to go! Great
> for you show car guys.
>
> UV protection is a funny thing. The carbon black used in black color
> adds protection but we used to make a part out of PE that was avail in
> red,yellow,blue,white,and black. (Those hats with numbers on them they
> used to put on your car at service centers.) Same plastic, no other
> additives and by far the best UV protection was red.The worst was white.
> We made another part out of PP or HDPE, (whichever was cheaper by the
> rail car that month). We added a clear liqued UV protectorate at the
> throat of the machine. By varing the mix ratio, we could get a specific
> amount of uv protection measured in monthes to years. So it is really
> whatever the blender or processor decided on.
>
> Hard to beat coroplast for lightweight and lowcost, and built in
> rigidity to prevent sagging.
>
--- End Message ---
--- Begin Message ---
I've got a book, "The Sports Car" by Colin Campbell. He came up with a
formula for 0-60 time based on engine torque that seems to track pretty well
with reality for ICE anyway:
Time 0-60 = (2 x vehicle weight in lbs/max motor net torque in ft. lbs.)
raised to the 0.6 power.
You could do a 0-60 and work it backwards and see what number you get.
Anybody got data handy to verify if this is close for an EV?
Marty
----- Original Message -----
From: "Jeff Major" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, May 16, 2007 9:00 AM
Subject: Re: Torque?
Hey Patrick,
You could put it on a dynamometer. Or do a draw bar
pull test. Strap the truck to a stationary object
with a force gague (or big spring scale) and floor it.
Assuming the tires don't spin, the force you read
times the rolling radius is the torque at the wheel.
The motor will put out this maximum torque from zero
to about 7000 RPM.
I have some test data from an EV1 motor. I thought
the S-10E used the same motor and control. But the
EV1 was rated at 100 KW and the S10E at 85 KW, so
there may be some control limit or something to
derate, possibly for longer battery range. My test
data for the EV1 motor showed a peak motor torque of
132 lb.ft.
Hope this helps.
Jeff
--- [EMAIL PROTECTED] wrote:
Hi,
I have a 1998 Chevy S10EV with an 85kW (114
horsepower) three-phase, liquid
cooled AC induction motor. How could I determine
the torque?
Thanks,
Patrick
____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play
Sims Stories at Yahoo! Games.
http://sims.yahoo.com/
--- End Message ---
--- Begin Message ---
Isnt that black PVC heavy though? That is why I was saying aluminum.
That stuff is light.
-----Original Message-----
From: Mark Ward [mailto:[EMAIL PROTECTED]
Sent: Wednesday, May 16, 2007 11:06
To: ev@listproc.sjsu.edu
Cc: Dewey, Jody R ATC COMNAVAIRLANT, N422G5G
Subject: RE: belly pan plastic
I am going to use a large sheet of black pvc. It is tough, cheap and
easy to install with push-pins so you can remove it later. Use
injectible foam to fill any gaps as needed and hit it with paint. Works
for me.
Mark Ward
95 Saab 900SE "Saabrina"
www.saabrina.blogspot.com
---- "Dewey wrote:
> What is wrong with using Aluminum? A 4x8 sheet of 18 gage aluminum is
> cheap. You could also bend it around obstructions or form it where it
> needed to be. It is light and will not crack or deform when exposed
> to oils. You can also put in small openings for venting if needed.
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> On Behalf Of Jeff Shanab
> Sent: Wednesday, May 16, 2007 9:14
> To: Electric Vehicle Discussion List
> Subject: Re: belly pan plastic
>
> I am gonna disagree on your comparison between lexan and acrylic, But
> it depends on the grade of each. In most cases, you have them
interchanged.
> You are correct in it being a bad choice. Lexan gets damaged by
> oils.(actually it causes it to get brittle). Race cars use lexan
> windshields, bullet proof windows are sometimes lexan. Safety glasses
> are lexan. Both are inapproriate for a belly pan anyway.
>
> I have used the UHMW sheets to line the ramps for parts (from
> injection molding). The parts hit it from a few feet distance and the
> ramp liners lasted a long time.
>
> One more material is available from places like Precision Plastics or
> your local equivilant. The trade name is something like Vivek.
>
> Vivek is PTEG, the material used in 2 liter bottles. It is very tough
> and optically clear, UV stabilized, and is available in .062,.093,.125
> thick 4x8 foot sheets. If you want clear, This is the way to go! Great
> for you show car guys.
>
> UV protection is a funny thing. The carbon black used in black
> color adds protection but we used to make a part out of PE that was
> avail in red,yellow,blue,white,and black. (Those hats with numbers on
> them they used to put on your car at service centers.) Same plastic,
> no other additives and by far the best UV protection was red.The worst
was white.
> We made another part out of PP or HDPE, (whichever was cheaper by
> the rail car that month). We added a clear liqued UV protectorate at
> the throat of the machine. By varing the mix ratio, we could get a
> specific amount of uv protection measured in monthes to years. So it
> is really whatever the blender or processor decided on.
>
> Hard to beat coroplast for lightweight and lowcost, and built in
> rigidity to prevent sagging.
>
--- End Message ---
--- Begin Message ---
Speaking of off topic.
Hate to be joykiller but tax policy is out of range.
If we start talking about that here the end will be soon.
Interesting but plenty of other places for it.
On Wed, 16 May 2007 7:50 am, Lee Hart wrote:
Danny Miller wrote:
There are already test projects to replace fuel taxes and/or toll
roads with either an odometer reading or much more likely a GPS
system...
I fear this more "convenient" form of billing could quickly lead to it
becoming as complex as, and as much a scam as, a cell phone contract...
Also important is a closed "black box" system operated in your car is
extremely prone to privacy issues.
My concern with "solutions" like this is that they are generally bad
for the people and good for someone else (the government, and the
companies that get the monopoly on selling you these systems). We pay
the costs, but the benefits go to someone else.
I believe that it you added up all the costs/benefits of hybrid and
electric vehicles, the benefits would already exceed the costs due to
lost gasoline revenues (reduced oil imports, less air pollution, fewer
health problems, lighter vehicles so less wear on the roads, etc.) So,
these fuel tax replacement systems cost more than they're worth.
Read "Other Days, Other Eyes" by Bob Shaw. It's a science fiction story
about a humble little invention that seems innocuous enough, but that
gradually grows to produce a dystopian future where the government can
literally watch and record everything that everyone does.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
--- End Message ---
--- Begin Message ---
Sorry for asking but does anyone know of a good steam car group?
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
--- End Message ---
--- Begin Message ---
But I still haven't seen an answer to a very important question (maybe I
missed it). Halfway down the strip, when your pack is halfway discharged,
your caps have a lot less voltage output to overcome motor back EMF, right?
Or do these Maxwells do some magic where they don't discharge linearly like
normal caps, but instead hold a voltage plateau (more or less) until near
the end like batteries?
Marty
----- Original Message -----
From: "Jeff Major" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, May 16, 2007 10:03 AM
Subject: Re: Using Audio Capacitors for Dragsters
I have tested a lot of Optimas and never saw anything
close to 3 milliOhms. Always much higher. On the
other hand, when testing Maxwell ultracaps, the
resistance is lower than spec. Tested on a 9 pack of
2600 Farad cells (22.5 volts) was 4 milliOhms and did
not change much with temperature or state of charge.
The 9 cell pack weighed 14 pounds. Optima about 40
pounds. Hence a much better power density for the
cap.
Jeff
--- End Message ---
--- Begin Message ---
On 5/16/07, Lee Hart <[EMAIL PROTECTED]> wrote:
Kaido Kert wrote:
> While you are correct that Solar still has hard time paying off, your
> weight numbers are based on silicon panels. Look at thin-film instead,
> like PowerFilm ( http://www.powerfilmsolar.com/ ) which is pretty
> available, and there are others.
> The added weight is next to nothing, cost, however ..
If you're putting PV panels on a car, then you have serious surface area
limitations, but weight hardly matters. In this case, you want PV cells
with the highest energy per unit area. This generally means silicon
monocrystal cells, as used in spacecraft and solar raycers.
If you're putting PV panels on a building roof, then surface area is not
much of a problem. People use 2-3 times the area to get the same the
same amount of energy, in order to get a much lower price. Thin film and
amorphous cells excel in these applications.
Also, I distinctly recall a fellow in Callie who has a RAV4 and solar
panels all over his house say that the power he sells to the grid
covers the cost of the panels, given he bought the whole setup on a
home equity loan. The excess power revenue is -more- than his payment
per month so it effectively cost him nothing to do. Sure, there are a
few fixed costs, but there is zero payback time since the asset is
producing enough revenue to offset the loan+interest.
--T
--- End Message ---
--- Begin Message ---
I would go to Jay Leno's site and ask him. He has a stanley steamer and
he would know all the skinny on the groups and such.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of GWMobile
Sent: Wednesday, May 16, 2007 11:36
To: ev@listproc.sjsu.edu
Cc: [EMAIL PROTECTED]
Subject: Does anyone know of a good steam car group?
Sorry for asking but does anyone know of a good steam car group?
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
--- End Message ---
--- Begin Message ---
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Timothy Balcer
> Sent: Wednesday, May 16, 2007 11:39 AM
> To: ev@listproc.sjsu.edu
> Subject: Re: Vehicle efficiency, wh/mile
>
> On 5/16/07, Lee Hart <[EMAIL PROTECTED]> wrote:
>> Kaido Kert wrote:
>> > While you are correct that Solar still has hard time paying off, your
>> > weight numbers are based on silicon panels. Look at thin-film instead,
>> > like PowerFilm ( http://www.powerfilmsolar.com/ ) which is pretty
>> > available, and there are others.
>> > The added weight is next to nothing, cost, however ..
>>
>> If you're putting PV panels on a car, then you have serious surface area
>> limitations, but weight hardly matters. In this case, you want PV cells
>> with the highest energy per unit area. This generally means silicon
>> monocrystal cells, as used in spacecraft and solar raycers.
>>
>> If you're putting PV panels on a building roof, then surface area is not
>> much of a problem. People use 2-3 times the area to get the same the
>> same amount of energy, in order to get a much lower price. Thin film and
>> amorphous cells excel in these applications.
>
> Also, I distinctly recall a fellow in Callie who has a RAV4 and solar
> panels all over his house say that the power he sells to the grid
> covers the cost of the panels, given he bought the whole setup on a
> home equity loan. The excess power revenue is -more- than his payment
> per month so it effectively cost him nothing to do. Sure, there are a
> few fixed costs, but there is zero payback time since the asset is
> producing enough revenue to offset the loan+interest.
>
> --T
Plus the interest (he's not paying) is tax deductible so he gets even more
benefit.
--
Stay Charged!
Hump
I-5, Blossvale NY
--- End Message ---
--- Begin Message ---
Hi,
> Subject: Orbitals vs. Optimas (was: Doin' the math)
> One of the most obvious differences is that Orbitals have a separate
> valve for each cell. Optimas have two valves for a common head space
> for all of the cells.
>
> The common manifold on an Optima allows the possibility of
> water transfer between cells. Cells that reverse or heat up can
> evaporate water while cooler surrounding cells can condense this
> water. Cells that charge up early take the brunt of the load to
> pressurize the entire head space, thus losing more water than the
> other, slower to charge, cells.
>
> Especially under abusive conditions, the separately-valved
> cells should, in theory, offer a cycle life advantage.
I'm a little confused, wouldn't the common manifold model be more
likely to keep the water inside the battery (water xfer from 'hot' cell
to'cold' cell) and thus have the better life cycle?
---
Steve
____________________________________________________________________________________Luggage?
GPS? Comic books?
Check out fitting gifts for grads at Yahoo! Search
http://search.yahoo.com/search?fr=oni_on_mail&p=graduation+gifts&cs=bz
--- End Message ---
--- Begin Message ---
Marty,
It behaves like a capacitor. E = 0.5*C*V**2. Any
magic lies in the large value of C.
I am not saying caps are better for drag races. Just
trying to give some facts as I know from experience.
A drag race is just an application and you choose your
energy storage system to what you think best.
I was using ultracaps for hybrid vehicles and am
impressed by them. I can discharge or recharge the
pack in about 10 seconds. Try that with a battery.
Jeff
--- Marty Hewes <[EMAIL PROTECTED]> wrote:
> But I still haven't seen an answer to a very
> important question (maybe I
> missed it). Halfway down the strip, when your pack
> is halfway discharged,
> your caps have a lot less voltage output to overcome
> motor back EMF, right?
> Or do these Maxwells do some magic where they don't
> discharge linearly like
> normal caps, but instead hold a voltage plateau
> (more or less) until near
> the end like batteries?
>
> Marty
>
> ----- Original Message -----
> From: "Jeff Major" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Wednesday, May 16, 2007 10:03 AM
> Subject: Re: Using Audio Capacitors for Dragsters
>
>
>
> I have tested a lot of Optimas and never saw
> anything
> close to 3 milliOhms. Always much higher. On the
> other hand, when testing Maxwell ultracaps, the
> resistance is lower than spec. Tested on a 9 pack
> of
> 2600 Farad cells (22.5 volts) was 4 milliOhms and
> did
> not change much with temperature or state of charge.
> The 9 cell pack weighed 14 pounds. Optima about 40
> pounds. Hence a much better power density for the
> cap.
>
> Jeff
>
>
>
____________________________________________________________________________________Sick
sense of humor? Visit Yahoo! TV's
Comedy with an Edge to see what's on, when.
http://tv.yahoo.com/collections/222
--- End Message ---
--- Begin Message ---
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Marty Hewes
> Sent: Wednesday, May 16, 2007 11:29 AM
> To: ev@listproc.sjsu.edu
> Subject: Re: Using Audio Capacitors for Dragsters
>
> But I still haven't seen an answer to a very important question (maybe I
> missed it). Halfway down the strip, when your pack is halfway discharged,
> your caps have a lot less voltage output to overcome motor back EMF,
> right?
> Or do these Maxwells do some magic where they don't discharge linearly
> like
> normal caps, but instead hold a voltage plateau (more or less) until near
> the end like batteries?
>
> Marty
>
> ----- Original Message ---
You set your cap pack up, so at the end of the run it is still in the range
needed.
For example, (ficticious numbers mainly) our favorite series motors are pretty
much capped at 170volts, so we get an EHV-Zilla, set it to max motor volts of
170, and size a cap pack that will start at the high end of the Zilla and still
be above 170 at the end of the run.
Or we get really smart and listen to the guy that has already done the research
and determined a much better solution.
--
Stay Charged!
Hump
I-5, Blossvale NY
--- End Message ---
--- Begin Message ---
TrotFox Greyfoot wrote:
Define cheap. I'm finding prices from $70 for .032" up to +$300 for
18ga. This is something I've thought about doing to my ICE car (for
those spirited freeway runs) but at those prices I'd certainly be
using Coroplast!
If the goal is aerodynamics, then you may want something that bends and
curves easier than Coroplast. It is basically a flat rigid sheet, that
kinks if you bend it too much.
Years ago, I read an article where the author did extensive
experimentation with aerodynamics to improve efficiency. It included a
belly pan, a rounded nose, and various rounded and pointed tail cones.
Because he didn't know what shapes were going to work, he used very
cheap simple methods to make the aero parts. The belly pan was canvas
stretched tight, and then painted with polyester resin to stiffen it.
The nose and tail cones were vinyl plastic "balloons", with expanding
foam sprayed into them to stiffen it. Only after he had figured out the
shapes that worked did he take the time and expense to make permanent
stronger fiberglass parts.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
What is his site?
And I mean email group although a physical meeting group would be good
too .
On Wed, 16 May 2007 8:57 am, Dewey, Jody R ATC COMNAVAIRLANT, N422G5G
wrote:
I would go to Jay Leno's site and ask him. He has a stanley steamer
and
he would know all the skinny on the groups and such.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of GWMobile
Sent: Wednesday, May 16, 2007 11:36
To: ev@listproc.sjsu.edu
Cc: [EMAIL PROTECTED]
Subject: Does anyone know of a good steam car group?
Sorry for asking but does anyone know of a good steam car group?
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
--- End Message ---
--- Begin Message ---
Yes Phil, thats what I thought too. Polycarbonate has very good at impact
resistance, acrylic does not.
----- Original Message -----
From: "Phil Marino" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, May 16, 2007 7:11 AM
Subject: Re: belly pan plastic
From: Danny Miller <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: belly pan plastic
Date: Tue, 15 May 2007 23:15:27 -0500
Lexan (a trade name for polycarbonate) is a poor choice for impact
resistance.
You may be confusing polycarbonate with acrylic ( plexiglass).
Polycarbonate has very high impact resistance. Here is a link to a
manufacturer of police riot face shields made of polycarbonate:
http://sites.securemgr.com/folder11152/index.cfm?id=25482&fuseaction=browse&pageid=39
And, motorcycle helmets are often made of polycarbonate.
Phil Marino
It is actually somewhat brittle, relatively speaking.
Unless you need the clarity, there is no reason to use it. Also, Lexan
scratches easier than acrylic (Plexiglass) and will be probably rapidly
scratched by road debris being under the vehicle.
They go:
LDPE
HDPE
UHMW-PE
UHMW-PE is expensive but unbelievably tough. It is also chemically
resistant to most anything it may come in contact with. However, all the
PEs are subject to UV damage unless otherwise specified. There are some
additives which may slow down the rate of UV damage. Black is always
better but this is an unusual color to get. Polypropylene is more UV
resistant than PE, but hardly "UV proof".
However, being UNDER a car should not get that much UV. I suspect this
will probably be safe even without a UV stabilized version.
The corrugated plastic material is called "Coroplast", at least that's the
biggest mfg'er. Coroplast is corrugated polypropylene and you'll find
many signs are made from it, even some of those stuck into the ground by
the road. It is readily available from any plastics supply store. It is
cheap, light, and tough, though nowhere near as strong as a 1/8" sheet of
UHMW. However, I'd suspect it's strong enough to do this job! Given the
low weight and cost, I expect this may be the best choice. Special
mounting procedures would need to be used, generally this means large
washers to spread out the force so it does not tear around the bolt holes.
Danny
David Roden wrote:
Solectria used a corrugated plastic material. It reminds me of the stuff
that US Postal Service carrying boxes are made from. (If you have a
business with a PO box, you probably have a collection of these boxes, so
you know what I mean.)
David Roden - Akron, Ohio, USA
EV List Administrator
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--- Begin Message ---
I went to the Ness website and browsed the ultra capacitors to see
where the current specs were these days.
Under very gentle discharge, ultra caps have a specific energy in the
range of 2 to 5 Watt-hours/kg. (This will be much lower under high
discharge. You won't get even half of that at max power.) Here are a
few comparisons:
AGM lead-acid ~ 30 W-hr/kg
NiCads ~ 45 W-hr/kg
Li-Ion FePo ~ 110 W-hr/kg
Now you are getting a glimpse at the problem. (This is why the folks
using caps pushed the car to the starting line, by the way.)
It takes at least 500 Watt-hours to get the KillaCycle to make a fast
run down the strip. This is about how much energy it takes to get a
619 lb bike with a 135 lb driver to cover the 1/4 mile in the 8's.
This does not include the burn out, the trip to the starting line, or
the trip back to the pits. This weight assumes your ultra caps weigh
just 161 lbs.
If you use the least-powerful ultra caps that have the most energy
per kg, and you (incorrectly) assume that you will be able to extract
the total maximum specific energy from them, the pack will weigh a
minimum of 100 kg = 220 lbs. This is about 60 lbs heavier than the
present pack. Oops! The bike goes much slower because it weighs more
AND is has much less available HP. Let's fix the HP problem.
If you were to select capacitors that are more powerful, (on par with
A123 cells) the specific energy would drop to 2 (or less.) This
boosts the cap pack weight to 500/2 = 250 kg = 550 lbs! Oops! The
bike goes even slower, not faster.
As we discussed in a previous note, you can't get all the available
energy out of a pack of caps at the drag strip because the drag
racing discharge curve is "upside down" from what the caps are able
to deliver. You need about _twice_ the weight in caps to deliver some
sort of HP at least half-way down the track. This pushes the pack
weight up even more!
As the pack weight grows, this boosts the vehicle weight, which
boosts the HP and energy requirements in proportion. It is a losing
proposition. It just won't work.
Ultra caps are not the best choice for drag racing. This is obvious
if you just do a few simple calculations. You don't even need to do
the more detailed calculations because the numbers are so bad, even
making wildly optimistic assumptions.
Bill Dube'
"Nuff said"?
--- End Message ---
