EV Digest 4363
Topics covered in this issue include:
1) RE: Calculating aero drag from torque?
by "Philip Marino" <[EMAIL PROTECTED]>
2) RE: Calculating aero drag from torque?
by "Roger Stockton" <[EMAIL PROTECTED]>
3) Re: Calculating aero drag from torque?
by "ProEV" <[EMAIL PROTECTED]>
4) Re: Heat and Charge (Cogeneration?), diode bridge
by "Philip Marino" <[EMAIL PROTECTED]>
5) EVLN(2010 Mitsubishi wheel-motor li-ion 150 km per charge EV)-LONG
by bruce parmenter <[EMAIL PROTECTED]>
6) EVLN(Reva Seva)
by bruce parmenter <[EMAIL PROTECTED]>
7) EVLN(�5.2m investment in Scotish EVs)
by bruce parmenter <[EMAIL PROTECTED]>
8) Re: Calculating aero drag from torque?
by Rush <[EMAIL PROTECTED]>
9) Re: Calculating aero drag from torque?
by Ryan Stotts <[EMAIL PROTECTED]>
10) Re: Calculating aero drag from torque?
by Evan Tuer <[EMAIL PROTECTED]>
11) Re: Calculating aero drag from torque?
by "ProEV" <[EMAIL PROTECTED]>
12) Re: Saft BB600s - disappointing results?
by "Christopher Robison" <[EMAIL PROTECTED]>
13) Re: Calculating aero drag from torque?
by "ProEV" <[EMAIL PROTECTED]>
14) Re: Calculating aero drag from torque?
by "ProEV" <[EMAIL PROTECTED]>
15) TdS Report #37: Monday Press Release - Modified Hybrid Vehicle Breaks 100
MPG Barrier
by [EMAIL PROTECTED]
--- Begin Message ---
Another idea might be to set a current limit such as 38 amps and drive our
bit of straight flat road and read the max rpm. There will be some error as
the pack is used up and voltage is lower for the same load. For best
accuracy, the test should be done each time with a full pack.
I assume this 38 amps is a pack current. If it is, the pack voltage will
certainly affect your RPM and speed. But, if you have the ability to set a
maximum motor current ( or, if you can measure motor current and just drive
at the speed that gives you the same motor current every time), that would
eliminate the battery pack voltage effects. You would be controlling motor
torque more directly.
Also, ( and maybe you already plan to do this) it might be a good idea to
determine how repeatable your measurements are by doing this test several
times ( even, on different days) without changing the car aerodynamically.
Then, you can get an idea how much non-repeatibiliy error you are dealing
with,.
Phil
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ProEV [mailto:[EMAIL PROTECTED] wrote:
> As a check, I took a look at data from our July race last
> year. We had the rev limiter on 5400 rpm (about 90 mph).
> We ran on the rev limiter for 13 seconds (and, no, this
> was not on purpose). During that time, the torque varied
> between 12.65 ft-lbs and 17.33 ft-lbs. Amps varied from
> 35.3 to 45.82. Voltage from 300.38 to 304.62. So power in
> watts was between 10,603 and 13,957.
How does SIADIS know the torque? I expect it is calculated based on
measured parameters such as voltage, current, and RPM.
> This varies fairly substantially from Uve's EV calculator
> predictions for 2,800 lbs, .32 drag Coefficient, 18 frontal
> area (sq. ft.). Single gear 3.9.
>
> Uve's EV calculator says 90 mph should require 34 ft-lbs
> torque.
Your car is running 2 Siemens drives; is SIADIS reporting a total of
12.65-17.33 ft-lbs, or is that per drive? Notice that it agrees fairly
well with Uve's calculator if it happens that you were only considering
the torque from one of the two drives (i.e. your values are pretty close
to 1/2 of Uve's).
Finally, Uve's drag calculations compute torque and HP at the wheel, not
the motor. If SIADIS is reporting a total (for both drives) of 12-17
ft-lbs, then this is 46.8-66.3 ft-lbs at the wheel based on your stated
3.9:1 overall drive ratio. Once again, this is about 1/2 of the value
Uve's calculator spits out (123 ft-lbs or 34.8HP), suggesting that you
may be only considering one of your two drives.
> Battery amps are shown as 122 and voltage at 288 volts.
> This gives power as 35,014 watts but this is calculated
> using a Kostov motor rather than the Siemens that we have.
You are only concerned with the drag calculations portion of Uve's
calculator, and this doesn't depend at all on the battery type/voltage
or motor type/voltage.
The drag calculations rely on the total vehicle weight (after
conversion, so make sure you fudge the battery/motor selections and the
initial weight/weight removed fields such that the end result agrees
with your actual curb weight) and the tire rolling resistance to compute
the rolling force (i.e. the drag force in lbs corresponding to the
rolling losses). It uses the Cd and frontal area values to compute the
aero drag component (in lbs) at various speeds. If you've entered a
non-zero relative wind factor, then the drag force will be adjusted
accordingly. Finally, the tire size/number of revolutions per mile is
used to convert the total (aero+rolling) drag force to a torque (at the
driven wheel, not the motor!). Finally, the torque and RPM are used to
copmute the HP (at the wheel) required at each speed.
If SIADIS reports motor output power (which it surely is capable of if
it can report torque and RPM), or if you simply calculate it from
SIADIS's values, then I would suggest comparing this resulting power
value to the power estimate from Uve's drag calculations instead of
relying on the torque values (which will depend on the accuracy of your
estimate of the true number of revolutions per mile of your wheels at a
given speed).
Uve's drag calculations are straightforward and should produce accurate
results for the parameters you input. If the results don't agree with
your observations and you are certain the observations are accurate
(e.g. include contributions from all drives), then the parameters you've
input to the model do not accurately describe your car.
You can measure rolling resistance, and the weight of the vehicle to
allow accurate calculation of the rolling losses. Frontal area and Cd
are trickier.
Hope this helps,
Roger.
--- End Message ---
--- Begin Message ---
Don,
Cliff, another interesting thing to try is to cover your car with a series
of 6" pieces of yarn, taped just on one end. Use a contrasting colour.
Then
video tape your car at speed from various different angles, and you may
notice where areas of turbulence are located.
(poor man's wind tunnel)
Don
That helps visualize turbulence and flow and give ideas about what to try
but it doesn't give that 'did the change help or hinder overall drag' check.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
From: "Mark Hanson" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: <[email protected]>
Subject: Re: Heat and Charge (Cogeneration?), diode bridge
Date: Mon, 16 May 2005 13:23:58 -0400
This is 2-diode center tap full wave is a standard for Lester chargers
(just
on the power line instead), probably more efficient than a fullwave bridge
which is dissipating power into 4 diodes instead of two.
Mark
Yes. A center-tap full-wave bridge is more efficient because of this -
there is only a single diode voltage drop instead of two diode drops in
series ( 50% less power lost in the diodes).
The disadvange ( general) of the center-tap full-wave bridgeis that the
transformer ( and other wiring) is not used as effectively because the power
factor is lower.
In this particular case, thought, that is not a disadvantage. Because you
would be drawing only half of the power from the line ( compared to the 220
full-wave bridge configuration, where half of the line power is lost ( or
used) as heat, the transformer heating would be lower.
The RMS current ( the only thing you need to know to determine wire heating)
would be less by 30% in each leg, the wire heating (and transformer heating)
would be less. BUT, you do have to make sure that the neutral conductor
is sized the same as the two hot conductors.
The best way, though, would be to do what Lee suggested - use a full-wave
bridge on a 110 line. Then, you're drawing only the power you really need
to charge the batteries, and the power factor is also better.
Phil
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EVLN(2010 Mitsubishi wheel-motor li-ion 150 km per charge EV)-LONG
[The Internet Electric Vehicle List News. For Public EV
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--- {EVangel}
http://www.investors.com/breakingnews.asp?journalid=27606112&brk=1
Mitsubishi Motors to Drive Forward Development of Next-generation
EVs; Colt EV Test Car Uses In-wheel Motors & Lithium-ion
Batteries
Tokyo, Japan, May 12, 2005 (JCN Newswire via COMTEX) -- Tokyo,
May 12, 2005 - (JCN Newswire) - Mitsubishi Motors has
chosen to center its development of next-generation electric
vehicle technology on in-wheel motors and on lithium-ion
batteries that the company has been working on for several years.
Currently working on a test vehicle that utilizes these
technologies, which it has dubbed the Mitsubishi In-wheel motor
Electric Vehicle (MIEV) concept, the company also envisages their
application to hybrid electric vehicles and fuel cell vehicles.
The in-wheel motor makes it possible to regulate drive torque and
braking force independently at each wheel without the need for
any transmission, drive shaft or other complex mechanical
components. For this reason, MIEV offers highly promising
potential in the ongoing evolution of Mitsubishi's all-wheel
control technology that is employed so successfully in the Lancer
Evolution, Pajero and other 4WD models. The fact that the drive
system is housed inside the wheel itself offers significantly
greater design freedom and also makes it easier to locate such
space-consuming components as the battery system, fuel cell
stacks and hydrogen tanks used in hybrid and fuel cell vehicles.
Lithium-ion battery technology offers superior specific energy,
specific power, and life over other types of rechargeable
batteries and as such is expected to contribute to higher top
speeds, extended cruising ranges and to greater weight reductions
in hybrid and fuel cell vehicles.
Mitsubishi Motors has already started development and testing of
the MIEV concept using a production compact vehicle, Colt, to
serve as the rolling test bed. The Colt EV uses rear in-wheel
motors powered by a lithium-ion battery system. The company is
also currently developing a more powerful in-wheel motor for use
in a 4WD test car. The Colt EV will be on display at the "2005
Automotive Engineering Exposition" to be held at the Pacifico
Yokohama Exhibition Hall, Yokohama from May 18 through May 20.
MIEV concept
Mitsubishi Motors was one of the first automakers to start
research into and development of the electric vehicle as an
alternative fuel vehicle. In recent years, the company has turned
its attention to the practical application of high-performance
lithium-ion battery power to propel FTO EV and Eclipse EV
experimental vehicles in 24-hour distance and public road test
programs.
Exploiting the benefits of lithium-ion battery and in-wheel motor
technology, the MIEV concept opens up new possibilities in terms
of alternative fuel vehicle development. As well as seeking
further possibilities for the EV, Mitsubishi Motors is also
looking at the application of the MIEV concept to hybrid and fuel
cell vehicles.
- In-wheel motor
Further evolution of all-wheel control technology:
A major benefit of the in-wheel motor is that it enables drive
torque and braking force to be regulated with high precision on
an individual wheel basis in both two- and four-wheel drive
systems without requiring transmissions, drive shafts,
differential gears or other complex and heavy components. The
in-wheel motor therefore holds great promise in terms of the
contribution to the further evolution of Mitsubishi's all-wheel
control technology that enjoys high critical acclaim on such
production models as the Lancer Evolution and Pajero.
Greater freedom in layout design:
Housing the drive system in the wheels gives greater freedom in
designing the layout. This will facilitate the conversion of IC
engine-powered vehicles into hybrid vehicles without requiring
the introduction of complex hybrid power systems. It will also
make it easier to provide room for space-consuming components
such as fuel cell stacks and hydrogen tanks in fuel cell
vehicles. The space-saving benefits of the in-wheel motors also
offer exciting possibilities in terms of body design. Designers
will be able to create innovative exteriors, improve dynamic
performance through weight distribution optimization, provide
roomier interior space and improve crash worthiness through
optimization of the structural framework.
- Lithium-ion battery
Lithium-ion battery technology offers advantages of specific
energy, specific power, and life over other types of rechargeable
batteries. Mitsubishi Motors has already built several test
vehicles using lithium-ion battery systems, including the
Mitsubishi HEV in 1996, the FTO-EV in 1998 and the Eclipse EV in
2000. The FTO-EV set a multiple-charge 24-hour distance world
record on a proving ground, while the Eclipse EV covered over 400
km on public roads on a single battery charge. These and other
testing programs have enabled the company to verify the practical
applicability of this type of battery.
Colt EV profile
The in-wheel motor test car, Colt EV, is based on the standard
compact vehicle, Colt. After removing the combustion engine, fuel
tank and transmission, two in-wheel motors were fitted to the
rear wheels and powered by a floor-mounted lithium-ion battery
system.
Rigorous proving ground tests are now being conducted on the Colt
EV. The test car is scheduled to undergo a tuning program with
independent control of drive torque and braking force for left
and right wheels to improve dynamic performance. After receiving
vehicle type certification, Colt EV will undergo verification
testing on public roads. Mitsubishi Motors will use the on-road
testing program to identify and resolve any problems unique to
the in-wheel motor vehicle, including any deterioration in road
holding and ride comfort due to increases in un-sprung weight, as
well as reliability and durability issues in the in-wheel motor
system and its peripheral components (suspension, wheels,
tires).
Mitsubishi Motors is continuing its motor and battery research
and development programs as it seeks to improve performance while
reducing size and weight. The company is currently working on a
50kW in-wheel motor for 4WD vehicle use that will eventually
feature individual drive torque and braking force control for
each wheel.
About Mitsubishi Motors Corporation
Mitsubishi Motors Corporation was established in 1970 and is one
of the few automobile companies in the world that produces a full
line of automotive products ranging from 660-cc mini cars and
passenger cars to commercial vehicles and heavy-duty trucks and
buses. The company also operates consumer financing services and
provides this to its customer base. Contact: Corporate
Communications Fumio Nishizaki
[EMAIL PROTECTED]
Copyright (C) 2005 JCN Newswire. All rights reserved. A division
of Japan Corporate News Network K.K. Copyright �2005
MarketWatch, Inc. All rights reserved.
===
http://www.itv-motoring.com/news/2005/may/12/6090.asp
Electric Colt (12 May 05)
Mitsubishi's development of electric cars is being centred on
something called the Mitsubishi In-wheel motor Electric Vehicle
concept, or MIEV for short. As the name suggests, the basic idea
is to control acceleration and braking through motors which are
fitted in the wheels, thereby reducing the amount of equipment
carried in the rest of the car and eliminating the need for any
transmission components.
Mitsubishi Colt 27 - EV Test Vehicle.
[image]
A development vehicle based on the Colt hatchback (pictured) uses
these motors in the rear wheels, but Mitsubishi is hinting that
the eventual aim is to fit them to all four. That would represent
a step forward in the company's development of four-wheel drive
systems, as seen in such diverse present-day models as the Shogun
and the Lancer Evo.
Another part of Mitsubishi's electric vehicle concept is the
continuing development of lithium-ion batteries. These have been
used in Mitsubishi test vehicles since 1996, and the company says
that they offer advantages in terms of specific energy, specific
power and battery life.
===
http://www.newratings.com/analyst_news/article_820600.html
MMC +2.2% On Electric Car Plan;Some Skeptical
Thursday, May 12, 2005 10:03:12 PM ET Dow Jones Newswires
0155 GMT [Nikkei/Dow Jones] Cosmo Securities strategist not
impressed by Mitsubishi Motors' announcement yesterday
it plans to commercialize electric vehicle in 2010 for world's
first full-scale marketing of such cars. "It will be hard to see
a true rise in the share price until the company addresses more
basic problems like reforming of its sales and production
systems," he says.
===
http://www.japantimes.co.jp/cgi-bin/getarticle.pl5?nb20050512a1.htm
Troubled MMC plans to launch electric minicar
By KAHO SHIMIZU Staff writer
Mitsubishi Motors Corp. said Wednesday it plans to launch an
electric minivehicle by 2010, choosing to focus resources on
development of electric vehicle technology to differentiate
itself from automakers already producing hybrid-engine cars.
"The reason we chose to go with EV (technology) is that . . . we
can sell our originality to consumers" while helping at the same
time to resolve environmental problems, MMC senior executive
officer Tetsuro Aikawa told a news conference at the automaker's
head office in Tokyo.
MMC is developing electric vehicles that have "in-wheel motors,"
which are encased in their rear wheels, and lithium-ion batteries
under their back seats.
The batteries are charged by plugging the vehicle into a socket,
MMC said, adding that the running cost of an electricity-powered
vehicle is far less than that for one with a conventional
gasoline engine.
Ahead of its introduction to the general market, MMC said it will
first sell its electric minivehicles to fleet operators in 2006.
MMC said it hopes to sell the vehicles for around 2 million yen
each, adding that this can be achieved if it produces 5,000 units
annually.
Conventional minivehicles usually cost less than 1 million yen,
but the company said the price difference can be minimized with
the help of government subsidies for purchasers of
environmentally friendly vehicles.
The struggling automaker said it has been working on electric
vehicles since the early 1970s and has accumulated relevant
knowhow, thus reducing the cost of research and development.
Electricity-powered vehicles emit no carbon dioxide, but their
use has been limited because current models are extremely
expensive and can travel no farther than 100 km per charge.
At present, MMC's prototype EV is equipped with a 150-kg battery
and runs 150 km per charge. The company plans to extend that
range.
"We hope to first target environment-conscious companies and
government agencies, and then women drivers who are conscious of
both cost and the environment," Aikawa said.
The Japan Times: May 12, 2005 (C) All rights reserved
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Bruce {EVangel} Parmenter
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EVLN(Reva Seva)
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http://timesofindia.indiatimes.com/articleshow/1110492.cms
Reva Seva INDIASPORA/CHIDANAND RAJGHATTA
[ SUNDAY, MAY 15, 2005 12:56:32 AM ]
Foreign leaders invited to George Bush�s ranch in Crawford, Texas
are usually treated to a drive around his 1500-acre estate in his
Ford F-250 with the President himself behind the wheel. The
gas-guzzler offers a mileage of around 4.5 miles per litre
according the US government website fueleconomy.gov. Russian
President Putin, one of Bush�s charmed guests to ride in the
mini-truck, returned the compliment last week by driving Bush
around his dacha in his vintage 1956 Volga, whose mileage can�t
be much better. Those who study tea leaves or tire tracks may
read meanings into their choice of vehicles.
Not having seen pictures or footage of Prime Minister Manmohan
Singh behind the wheel, one isn�t sure if he drives. But assuming
he has in his days as an academic and a bureaucrat, here�s an
interesting thought. Is it possible that when Bush visits India
this winter, Singh can drive him � perhaps from South Block to
Parliament since he has no ranch or dacha? And if he could, what
vehicle should he use?
How about Reva, an India-made electric car that is winning rave
notices in the West, including in automobile-saturated America?
Forbes magazine called it exotic because it is made in India, "A
nation which is becoming increasingly famous as a technological
hub." And from Automobile.com: "As a technology showcase, the
(Reva) concept car is a completely operational tool to
demonstrate India�s expertise in developing electric vehicle
technology to the world... India�s research and development is a
case in point that the technology behind alternative-power
zero-emission vehicles is alive and kicking."
I won�t belabour the encomiums and sound like a shill for Reva.
But it�s not so much the car as the concept that is driving me to
make this far-out suggestion. At a time of growing energy crisis,
at a time when India is finally learning that the future lies in
innovation not imitation, what better "body language" than
driving the leader of the SUV nation around in a hip, home-made
electric buggy?
The first Indian vehicles have already appeared on the American
landscape. If you look hard enough, you will find a few Mahindra
tractors in the American heartland (manufactured in Texas and
Georgia). Bajaj two- and three-wheelers nip around some urban
centres, mainly used to deliver pizza.
But there are no Indian cars on the roads dominated by American,
Japanese and European vehicles. For that matter, there are not
many Indian technologies in the US. From spirituality to
software, we export many conceptual products. But when it comes
to nuts and bolts, chips and circuits, we are not on the screen.
Of course, don�t expect Reva to be hurtling up Interstate 95
anytime soon, not in a country where families don�t think twice
about a 40-mile drive for dinner at Olive Gardens. A six-hour
charge gives it a range of about 120 miles, which is quite a
distance in India but could be a daily commute to work in the US.
Heck, for that matter, it may not even work in India, because, as
a friend cynically pointed out, who can assure an uninterrupted
six-hour power supply?
But jokes aside, Reva and other innovative products like the
simputer (even though it has bombed), speak to an Indian quest to
break new ground. We may be cottoning on a little late to the
manufacturing boom based on borrowed ideas and designs, but there
is no reason why we can�t have a head start on the technologies
of tomorrow. Especially, where it concerns energy and water, two
resources that are expected to cause most conflict in the 21st
century.
Copyright � 2005 Times Internet Limited. All rights reserved.
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Bruce {EVangel} Parmenter
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EVLN(�5.2m investment in Scotish EVs)
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--- {EVangel}
http://business.scotsman.com/technology.cfm?id=526262005
ITI steers �5.2m into electric vehicle projects
DOUGLAS FRIEDLI
TECHNOLOGY for the next generation of electric vehicles will be
developed in Scotland following a �5.2m investment by the agency
set up to develop innovation in energy.
The Intermediary Technology Institute for Energy has revealed the
first two projects which it will fund, just over a year after it
was set up by the Scottish Executive to identify market
opportunities and commission research.
The Aberdeen-based agency, headed by chief executive Tony Amor,
is the last of the three new ITIs to reveal how it will spend
part of its �150m budget over 10 years.
A source at the institute said the pace of deals was likely to
increase, and that it would reveal "six to eight" new projects in
the next 12 months.
ITI Energy will spend �4m on a scheme to modify mobile phone-type
batteries for use in cars and laptop computers in collaboration
with Qinetiq, the former defence research agency, and St Andrews
University.
The new batteries last four times as long as conventional ones,
raising the possibility of electric passenger vehicles which can
travel for hundreds of miles between charges.
The ITI will pump a further �1.2m into a battery management and
power control system with MPower, the Dundee battery producer,
and Axeon, the Aberdeen computer technology company. Hamish
Grant, Axeon�s chief executive, said the engine management system
would be used to gauge how much power is left in the high-energy
lithium ion batteries.
Jim Wallace, the enterprise minister, said the twin projects
would strengthen small companies in Scotland, create intellectual
property which could be exploited in the future and develop new
research and development capabilities.
He said: "ITI Energy has brought together some of Scotland�s most
innovative companies with our world-class research to develop
technologies with real prospects of significant penetration of
global markets and sizeable future economic benefit."
ITI Energy got off to a slow start, partly because it had trouble
recruiting a chief executive. Amor, who eventually joined last
year, said: "We are looking for a combination of a financial
return on our investment and an economic return to Scotland. We
expect to create new companies and enhance existing companies."
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--- Begin Message ---
Exactly what I was planning to do with my conversion and try and modify some
areas that were very turbulent.
Rush
> Cliff, another interesting thing to try is to cover your car with a series
> of 6" pieces of yarn, taped just on one end. Use a contrasting colour. Then
> video tape your car at speed from various different angles, and you may
> notice where areas of turbulence are located.
>
> (poor man's wind tunnel)
>
>
--- End Message ---
--- Begin Message ---
ProEV wrote:
> Highway driving staying between 60-65, we are seeing
> around 225 watt-hrs per mile.
Is that what each motor was using or the total for both?
--- End Message ---
--- Begin Message ---
On 5/16/05, ProEV <[EMAIL PROTECTED]> wrote:
> > The first thing I would do is repeat the test and try to verify that
> > data, or ignore it and start again with some 60mph tests.
> > If it's correct - Good news, you have one very aerodynamic Subaru -
> > Bad news, making it much better might be difficult :)
> >
> >
>
> Another data point. Highway driving staying between 60-65, we are seeing
> around 225 watt-hrs per mile.
so that's about 13-14kW average? This is a far more believable figure.
(Or I could be talking nonsense, it's late!)
--- End Message ---
--- Begin Message ---
Phil
I assume this 38 amps is a pack current. If it is, the pack voltage will
certainly affect your RPM and speed. But, if you have the ability to set
a maximum motor current ( or, if you can measure motor current and just
drive at the speed that gives you the same motor current every time), that
would eliminate the battery pack voltage effects. You would be
controlling motor torque more directly.
Interesting idea. I will have to check the software.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
Thanks Lee, this is exactly what I had feared. I could lower the load
resistance to get more current (by shortening the welding cable, improving
connections, using a larger shunt, etc), but the bottom line is that my
existing setup is already pulling the cell voltage down too low, and if
anything these measures would make that problem worse.
I haven't been able to spend any more time with them since my last post,
but I think I know enough now to conclude that these cells, though
seemingly nearly ideal for a "normal" car, will not be adequate for my
application. For what it's worth I'll continue testing to see how far the
cell voltage will drop (perhaps resulting in the destruction of the cell),
but I no longer expect I'll be using these in my truck.
Tim (and anyone else), if you happen to catch an auction for similar cells
from Marathon instead of Saft, I'll be *very* excited to hear about it.
--chris
Lee Hart said:
> Christopher Robison wrote:
>> I've been testing a few of my designated "sacrificial" Saft BB600
>> cells this afternoon, with results I'm not sure how to interpret.
>> With a single cell shorted through a total of about 5 feet of 4/0
>> and that massive 3000A shunt, I got about 750A. Two cells in
>> series through a sandwich of two flattened 3/4" pipes as an
>> intercell connector made about 1100A. Three cells connected the
>> same way made about 1400A.
>
> This means you aren't really providing a low enough load resistance. An
> individual cell will obviously deliver just as much current as a string
> of cells in series if you can produce a low enough resistance.
>
>> Also, at 1400A, cell voltage fell to around 0.4V. The copper bus
>> bars were getting very hot, and the cells were warming noticeably.
>> How low of a voltage sag is "too low" with these cells?
>
> I would say that 0.4v is too low. I wouldn't load them to anything less
> than half of their no-load voltage. If you have 1.2v no-load, I wouldn't
> pull them any lower than 0.6v. This is the "half-power" point, where
> half your power is dissipated in the external load, and the other half
> in the cell itself. The power being dissipated in the cell itself is why
> you can't do this for more than a few seconds.
>
>> should I expect a "breaking in" period similar to lead acid?
>
> There will be some break-in, though not a pronounced as with lead-acid.
> --
> "Never doubt that the work of a small group of thoughtful, committed
> citizens can change the world. Indeed, it's the only thing that ever
> has!" -- Margaret Mead
> --
> Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
>
>
--- End Message ---
--- Begin Message ---
Roger,
As a check, I took a look at data from our July race last
year. We had the rev limiter on 5400 rpm (about 90 mph).
We ran on the rev limiter for 13 seconds (and, no, this
was not on purpose). During that time, the torque varied
between 12.65 ft-lbs and 17.33 ft-lbs. Amps varied from
35.3 to 45.82. Voltage from 300.38 to 304.62. So power in
watts was between 10,603 and 13,957.
How does SIADIS know the torque? I expect it is calculated based on
measured parameters such as voltage, current, and RPM.
I don't know how SIADIS gets torque. Victor?
This varies fairly substantially from Uve's EV calculator
predictions for 2,800 lbs, .32 drag Coefficient, 18 frontal
area (sq. ft.). Single gear 3.9.
Uve's EV calculator says 90 mph should require 34 ft-lbs
torque.
Your car is running 2 Siemens drives; is SIADIS reporting a total of
12.65-17.33 ft-lbs, or is that per drive? Notice that it agrees fairly
well with Uve's calculator if it happens that you were only considering
the torque from one of the two drives (i.e. your values are pretty close
to 1/2 of Uve's).
We only use one computer to read from the controllers so we are only reading
one. Then converted it from newton-meters and doubled it. The controllers
total Kw-hr records match so we are assuming they are sharing the load
equelly. I guess we better check that. This means two computers to read the
controllers and one to run the BMS. How many computers does the space
shuttle use?
Finally, Uve's drag calculations compute torque and HP at the wheel, not
the motor. If SIADIS is reporting a total (for both drives) of 12-17
ft-lbs, then this is 46.8-66.3 ft-lbs at the wheel based on your stated
3.9:1 overall drive ratio. Once again, this is about 1/2 of the value
Uve's calculator spits out (123 ft-lbs or 34.8HP), suggesting that you
may be only considering one of your two drives.
I was using motor torque from 'Range by gear and speed'. I missed the whole
'Drag Calculation' table.
Battery amps are shown as 122 and voltage at 288 volts.
This gives power as 35,014 watts but this is calculated
using a Kostov motor rather than the Siemens that we have.
You are only concerned with the drag calculations portion of Uve's
calculator, and this doesn't depend at all on the battery type/voltage
or motor type/voltage.
The drag calculations rely on the total vehicle weight (after
conversion, so make sure you fudge the battery/motor selections and the
initial weight/weight removed fields such that the end result agrees
with your actual curb weight)
Done
>and the tire rolling resistance to compute
the rolling force (i.e. the drag force in lbs corresponding to the
rolling losses).
I use the .0015 for low rolling resistance. We are running race slicks at 40
psi. I have been told the rolling resistance is very low.
> It uses the Cd and frontal area values to compute the
aero drag component (in lbs) at various speeds. If you've entered a
non-zero relative wind factor, then the drag force will be adjusted
accordingly. Finally, the tire size/number of revolutions per mile is
used to convert the total (aero+rolling) drag force to a torque (at the
driven wheel, not the motor!). Finally, the torque and RPM are used to
copmute the HP (at the wheel) required at each speed.
If SIADIS reports motor output power (which it surely is capable of if
it can report torque and RPM), or if you simply calculate it from
SIADIS's values, then I would suggest comparing this resulting power
value to the power estimate from Uve's drag calculations instead of
relying on the torque values (which will depend on the accuracy of your
estimate of the true number of revolutions per mile of your wheels at a
given speed).
I will look for motor output power.
Uve's drag calculations are straightforward and should produce accurate
results for the parameters you input. If the results don't agree with
your observations and you are certain the observations are accurate
(e.g. include contributions from all drives), then the parameters you've
input to the model do not accurately describe your car.
You can measure rolling resistance, and the weight of the vehicle to
allow accurate calculation of the rolling losses. Frontal area and Cd
are trickier.
Hope this helps,
It does.
Thanks
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
Ryan,
Is that what each motor was using or the total for both?
That is the readings from one doubled. I guess we will have to use another
computer and read both controllers for a better test.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
TdS Report #37: Monday Press Release - Modified Hybrid Vehicle Breaks 100 MPG
Barrier
Modified Hybrid Vehicle Breaks 100 MPG Barrier
In National 2005 Tour de Sol
Advanced Vehicles Demonstrate Zero Oil-Consumption
Reduced Climate-Change Emissions
FOR IMMEDIATE RELEASE
Contact: Nancy Hazard [EMAIL PROTECTED] 413-774-6051 x18
James Dunn [EMAIL PROTECTED] 508-870-0042 x108
Greenfield, MA - May 16, 2005 - A modified hybrid vehicle, a Honda Insight
driven by Brian Hardegen of Pepperell, MA, has broken the 100-mile-per-gallon
barrier over a 150-mile range in the National 2005 Tour de Sol held May 13-16
in Saratoga Springs and Albany, NY. A student team from West Philadelphia High
School in Philadelphia, PA, has taken top honors with its purpose-built hybrid
vehicle, which uses biodiesel instead of gasoline and produces 77% less
climate-change emissions compared to a conventional gas car.
During the National 2005 Tour de Sol - the 17th annual sustainable-energy and
transportation festival and competition -- over 60 hybrid, electric and
biofueled vehicles from throughout the U.S. and Canada demonstrated that we
have the technology today to power our transportation system with zero-oil
consumption and zero climate-change emissions. Each vehicle showed new ways to
reduce our dependence on foreign oil while reducing harmful pollutants.
"Each year, the Tour de Sol highlights the largest innovations in alternative-
energy technology and advanced fuel vehicles, showcasing the future of the
clean-energy and transportation industry," said New York State Gov. George E.
Pataki. "Over the last 10 years, we've invested unprecedented funding into the
research and development of clean-fuel technology and currently deploy more
than 4,300 clean-fuel vehicles in our state-operated fleets. I'm proud that
many of the cars and components featured in this year's Tour de Sol are being
developed right here in New York State, creating new markets and jobs for the
21st century while helping to clean our air and reduce our dependence on
foreign oil."
"The students, businesses, New York State government officials, auto companies
producing advanced vehicles, and people using new hybrid and biofuel vehicles
in the Tour de Sol are the new American heroes of the 21st century," said Nancy
Hazard, executive director of the Northeast Sustainable Energy Association in
Greenfield, MA, organizer of the Tour de Sol. "Every American is a winner
because of their efforts to design, build and use advanced vehicles that aim to
reduce imported oil and climate-change emissions today - offering an
alternative solution to the energy and climate-change crises that threaten life
as we know it."
Thousands of people came to see the vehicles and talk with the people
participating in the three exciting competitions held during the National 2005
Tour de Sol. There were 41 entrants in the new Monte Carlo-style Rally, with
several participating in the 100 MPG Challenge. The top-placing vehicles in
the Monte Carlo-style Rally were: a Honda Insight driven by Mike Lewis of
Portland, ME, averaging 79 MPG; a Toyota Prius driven by Jean Couto of
Marlboro, MA, with 61 MPG; and a biodiesel Volkswagen Passat, delivering 77 MPG
over a 500-mile range.
"We were very pleased by the performance of the various production vehicles
entered in the Monte Carlo-style Rally and 100 MPG Challenge," said James Dunn,
CEO of the Center for Technology Commercialization in Westboro, MA. The
overall average performance of the 29 Toyota and Honda hybrid sedans exceeded
60 MPG, with a modified Honda Insight from Brian Hardegen of Pepperell, MA,
delivering 107 MPG and a "plug-in" Toyota Prius from Valence Corp. in Austin,
TX, averaging 102 MPG over a 150-mile range. The average of the 5 biodiesel
vehicles was nearly 53 MPG, including the 20 MPG average of the Ford F250
pickup truck entered by Vogelbilt in West Babylon, NY. Two remarkable
production vehicles were new Ford Escape hybrid SUVs from the New York State
Energy Research and Development Authority as well as RadAir in Parma, OH,
achieving 35 and 43 MPG, respectively.
The most interesting overall vehicle was the novel "plug-in" hybrid
demonstrated by Valence Corp. and EDrive in Monrovia, CA. This is a modified
Toyota Prius with a much larger battery pack than the normal Prius, and charged
with external grid power. On a 150-mile run, this vehicle achieved 102 MPG on
the gasoline used, but also used 9 kilowatt-hours of electricity required to
charge the special lithium-ion batteries, which cost less than $1 to recharge.
Although this vehicle would be relatively expensive to buy if available today
(due to extra battery cost) plug-in hybrids may become a viable future
technology.
In the Tour de Sol Championship, which showcases concept vehicles built by
students and entrepreneurs as well as some production vehicles, all but two of
the entrants approached zero oil use by powering their vehicles with biodiesel,
electricity, solar or natural gas. Of these, St. Mark's High School in
Southboro, MA, and North Haven Community School, North Haven, ME, demonstrated
true zero-oil consumption and true zero climate-change emissions with their
modified electric Ford pick-up and Volkswagen bus, respectively, At home, they
recharge their vehicles from wind and solar - demonstrating what can be done
when electric vehicles are recharged by "clean electricity", which can be
purchased throughout the U.S.
Three top-placing teams -- West Philadelphia High School, Quebec Advanced
Transportation Institute (ITAQ) in St. Jerome, Quebec, Canada, and Western
Washington University in Bellingham, WA -- demonstrated incredibly low
greenhouse-gas emissions by running their vehicles on biodiesel. The ITAQ
entry got 67 MPG in a diesel Mercedes SMART vehicle.
The E-bike and NEV Competition attracted over a dozen vehicles ranging from
recumbent electric tricycles, to stand-up scooters, electric bicycles, and
4-wheeled /4-passenger NEVs (neighborhood electric vehicles). What all these
vehicles have in common is that they run on electricity and are designed to
meet our needs for local "around town" trips. The incredible efficiency of
these lightweight vehicles truly demonstrates what can be achieved in the field
of fuel efficiency. OptiBike of Boulder, CO, took first place with their
pedal-assisted electric bike.
In addition to the vehicles participating in the National 2005 Tour de Sol,
there were over 30 displays from auto, bus and NEV manufacturers, business and
government leaders, all working together to produce clean transportation
solutions for the U.S., Canada and beyond. Displays included: Toyota's hybrid
Prius, Highlander SUV and Lexus RX 400h; Honda1s three hybrid sedans --
Insight, Civic, and Accord -- its natural-gas Civic GX, and the FCX, one of its
30 hydrogen fuel-cell vehicles; natural-gas, propane and hybrid buses and
trucks; emission-reduction technologies for new ceramic brakes; biodiesel
suppliers; and lithium-battery manufacturers.
BACKGROUND:
Monte Carlo-style Rally & 100 MPG Challenge
The Monte Carlo-style Rally was created this year to offer advanced vehicle
owners the opportunity to demonstrate what their vehicles (production-line or
modified) can deliver as well as to compete for up to $10,000 in prizes. To
compete for the 100 MPG Challenge (which no entrant achieved this year)
entrants began at one of the 11 official stating sites around the U.S. and
Canada and drove a minimum of 500 miles to Stewart's Shops in Saratoga Springs,
NY. Other entrants traveled a minimum of 150 miles to Saratoga Springs, for
other prizes. Key Monte Carlo-style Rally organizers are the Automotive Career
Development Center and the Center for Technology Commercialization, with
Stewart's Shops and biodiesel supplier Environmental Alternatives providing the
fuel for all the entries. This year, 40 teams entered the new Monte Carlo-
style Rally.
E-Bike and NEV Competition The E-bike and NEV (neighborhood electric vehicle)
competition was created last year by RunAbout Cycles in Sunderland, MA. E-bike
and NEV manufacturers, distributors, entrepreneurs, hobbyists and students are
invited to participate in this two-day event. This year, over a dozen entrants
went through technical specification checks, displayed their vehicles and
participated in a range events of one, two or three hours.
Tour de Sol Championship Over a half million consumers have visited the Tour de
Sol since its creation in 1989 by the Northeast Sustainable Energy Association
(NESEA), and over 40 million print-and electronic--media exposures accrue from
the Tour each year. The Tour de Sol provides a key platform for vehicle
manufacturers, students and entrepreneurs to demonstrate future designs and
current products that aim to reduce oil and carbon emissions to zero. The
event provides news media the opportunity to provide timely and topical updates
on the status of sustainable energy and mobility. This year, over a dozen
teams participated in the Tour de Sol Championship which began in 1989. It aims
to inspire students and businesses to design, build, showcase and use concept
vehicles that push the envelope and work toward the ultimate goal of the event.
Sponsors The New York State Energy Research and Development Authority and the
Center for Technology Commercialization are the event's Premier Sponsors. Key
Sponsors are the U.S. Department of Energy, the New York Power Authority,
Toyota, the New York State Department of Environmental Conservation, New York
State Parks, Honda, Environmental Alternatives, and the Federal Highway
Administration.
NESEA - NESEA, the nation's leading regional education and advocacy
association, is a not-for-profit 501(c)(3) organization. NESEA aims to
accelerate the deployment and use of renewable energy and energy efficiency by
producing major sustainable-energy events that inspire and motivate large
numbers of people to get involved and make a difference.
For more information on all of the winners in the National 2005 Tour de Sol,
visit www.TourDeSol.org or contact NESEA at 413-774-6051.
NOTE TO ALL MEDIA: All results as well as photos are available upon request.
-30-
- - - -
The complete set of Tour de Sol Reports for 2005 can be found at:
http://www.AutoAuditorium.com/TdS_Reports_2005
The complete set of past Tour de Sol Reports can be found at:
http://www.FovealSystems.com/Tour_de_Sol_Reports.html
- - - -
The above is Copyright 2005 by Michael H. Bianchi.
Permission to copy is granted provided the entire article is presented
without modification and this notice remains attached.
For other arrangements, contact me at +1-973-822-2085 .
- - - -
For more on the NESEA Tour de Sol, see the web page at
http://www.TourdeSol.org
- - - -
Official NESEA Tour de Sol information is available from the sponsor,
the Northeast Sustainable Energy Association (NESEA) at
413 774-6051 , and 50 Miles Street, Greenfield, MA 01301 , and
[EMAIL PROTECTED] . All media enquiries should be addressed to ...
Jack Groh
Tour de Sol Communications Director
P.O. Box 6044
Warwick, RI 02887-6044
401 732-1551
401 732-0547 fax
[EMAIL PROTECTED]
--- End Message ---
