EV Digest 3279
Topics covered in this issue include:
1) Re: Fisher Fury EV Concept: Are these figures possible? Critiscisms? Comments?
Recommendations?
by Lee Hart <[EMAIL PROTECTED]>
2) Re: e-meter interference?
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Educational Outreach
by Lee Hart <[EMAIL PROTECTED]>
4) RE: Tickets for parking in EV parking IS OFF TOPIC
by "Tim Clevenger" <[EMAIL PROTECTED]>
5) attacking the ceramic heater through the firewall
by Ryan Bohm <[EMAIL PROTECTED]>
6) Re: Fisher Fury EV Concept: Are these figures possible? Critiscisms?
Comments? Recommendations?
by Victor Tikhonov <[EMAIL PROTECTED]>
7) Re: Tickets for parking in EV parking
by meat <[EMAIL PROTECTED]>
8) Re: Educational Outreach
by "Peter Eckhoff" <[EMAIL PROTECTED]>
9) Re: Pre-charge questions
by "Chuck Hursch" <[EMAIL PROTECTED]>
10) Re: Pre-charge questions
by "Chuck Hursch" <[EMAIL PROTECTED]>
11) NiZn cold weather experience
by fred whitridge <[EMAIL PROTECTED]>
12) Article in Jan 2004 Car & Driver magazine
by Lee Hart <[EMAIL PROTECTED]>
13) RE: Article in Jan 2004 Car & Driver magazine
by "Harris, Lawrence" <[EMAIL PROTECTED]>
14) Re: Fisher Fury EV Concept: Are these figures possible? Critiscisms?
Comments? Recommendations?
by Lee Hart <[EMAIL PROTECTED]>
15) Re: Pre-charge questions
by Lee Hart <[EMAIL PROTECTED]>
--- Begin Message ---
John Westlund wrote:
> I've posted here about a month ago with an idea of building
> a ~$50,000 EV that could do 0-60 in 5, 200 mile range, 120+
> mph top end
As you know, that is a *very* ambitious set of requirements. It's not
impossible with a $50,000 budget, but it is still challenging. Pretty
much everything needs to be done right. It can't be a conversion or
warmed-over kit car; it will have to be a scratch-built EV, something
like a clone of the GM EV-1 with Nimh batteries.
Getting 0-60 mph in 5 sec *and* a 200-mile range will require a pretty
expensive battery pack. Nimh can do it, but they are essentially
unobtainable.
LiIon might be able to do it, if you took the AC Propulsion approach
(thousands of laptop cells). But I have my doubts that it is feasible;
just too dang many parts and connections to be reliable.
I don't think lead-acids can do it. You could get the accelleration *or*
the range, but not both. They just don't have the necessary storage
capacity.
That leaves nicads a perhaps your best bet. They can provide the high
peak current, they (barely) have the energy storage capacity, and they
are actually available in EV sizes. The price is high, but not as high
as LiIon or Nimh.
> How about something that could be built for around $25,000,
> 0-60 around high 6 range, 140+ MPH top speed, 70-100 mile
> range, ~150 wh per mile highway consumption @55 MPH, and
> superb handling even with Nokia low rolling loss 13 inch
> tires?
This has a better chance for success. The Tango is an example of a car
that can do all this, using ordinary lead-acid batteries.
> The Fisher Fury kit car...
The trouble with most kit cars is that they get their light weight by
giving up strength. A high performance EV has to be exceptionally light
*and* exceptionally strong -- more so than any normal ICE car. By the
time you strengthened the frame, brakes, wheels, and suspension to carry
the weight of the batteries required, you've essentially built your own
car from scratch anyway.
Also, most kit car bodies are designed for looks, looks, and looks --
not strength, weight, or practicality. People who have built kit cars
often find them uncomfortable to drive; too many squeaks, leaks, poor
visibility, uncomfortable seating, etc. When the novelty wears off, they
go back to a conventional car as their daily driver.
> I will probably try to convert a Toyota Paseo(Very light, would
> allow good accel with cheap controller as a starter vehicle with
> a 216V pack or perhaps build a simple electric bike, each of which
> would cost $7,000 and $1,200 respectively.
I would suggest this approach. Try a simpler conversion, use it to learn
on, then sell it and move on to something more ambitious.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Roland Wiench wrote:
> I am going to install a Link-10 in my EV... I have to install the
> shunt in rear compartment of car, so as to take off the battery
> circuit, that is also fed by the battery charger. This distance
> from controller to shunt is 15 feet. It will take 25 feet of cable
> from the on dash meter to this shunt.
Noise filtering is a big, complex issue. Ad hoc solutions sometimes
work, but it helps a lot to understand what it going on. Then, you can
take action and KNOW what you are doing. Let me see if I can provide a
basic
description of what is going on.
Basic principles
----------------
1. The Faraday pail
In the 1830's Michael Faraday wanted to build a battery. He placed a
metal ice pail on some glass bottles, and sought to fill the bucket with
the mysterious electric 'fluid' recently discovered. He ran a wire from
his generator to the inside of the bucket, and cranked his generator a
bit. Then he carefully lowered his voltmeter into the bucket to see
where it contacted the electric 'fluid'. No voltage; the bucket was
apparently empty.
So he cranked some more, and measured again. Still nothing. In
frustration, he cranked the generator as fast and as much as he could.
STILL, when he lowered his voltmeter into the bucket, there was no
indication, no charge.
Where did it go? Puzzled, he reached to pick up the bucket and *WHAM*!
He got a tremendous shock from the static electric charge!
We now know that electrons are negatively charged, and repel each other.
They can also move freely in conductors, like that metal pail. So, all
the electrons moved to the OUTSIDE of the pail.
This is referred to as Faraday's Ice Pail experiment. It proves that you
can't have a charge inside a closed metal structure; it all flows to the
outside. This leads to
--- Principle One ---
We can block (shield) a circuit from the effects of outside fields by
putting it inside a closed metal container. It also works if you put a
noise source inside a closed metal container; the noise can't get out.
Practical containers have holes, but the principle still works as long
as there aren't too many holes and they aren't too big. Faraday found
that even something as skimpy as a wire bird cage could work. Thus, such
a shield is called a Faraday Cage.
So, you can shield something (like an E-meter or a motor) by putting it
inside a (mostly) closed metal enclosure of some kind. Connect this
sheld to whatever the circuit inside considers to be its ground
reference.
--- Principle Two ---
The shield can be any shape; even a long piece of metal tubing, slid
over a wire or wires. This is called shielded cable. The shield is NOT a
current-carrying conductor; it is only there to provide a faraday cage
around the wires inside. You only connect this shield to the circuit's
ground return at ONE point. The rule is; if the current in the wire and
its shield ARE NOT the same, then only connect the shield to ground at
ONE END.
Faraday was pretty smart; the Farad (the unit of capacitance) is named
after him.
2. Induction
Also in the 1830s, Michael Faraday and Joseph Henry worked independently
to figure out the relationship between electric and magnetic fields.
They knew that an electric current in a wire creates a magnetic field
(that's how you make an electromagnet). But they also noticed that a
*changing* current in a wire creates a *changing* magnetic field. And,
it works in reverse; a *changing* magnetic field induces a *changing*
current flow in a wire! This is how motors, generators, and transformers
work.
This became known as Faraday's Law. But he already had the Farad named
after him, so they named the basic unit of inductance the Henry.
--- Principle Three ---
When you run two wires next to each other, a changing current in one
will induce a changing current in the other. That means noise in one
wire couples its noise to all the rest! So keep noisy wires far away
from ones you want to be quiet (like motor wires and E-meter shunt
wires).
--- Principle Four ---
But there's an interesting trick. If you can arrange things so you have
two wires carrying EQUAL but OPPOSITE currents, then bundling these
wires tightly together makes their magnetic fields CANCEL. They are less
likely to pick up noise, and less likely to radiate noise to other
wires.
This is usually done by twisting the wires together (called a twisted
pair). The closer and tighter they are, the better it works. Thus it
works better with wires having thin insulation. Tighter twists usually
work slightly better, by insuring that the average distance between each
wire and any other conductors is the same.
Remember, the wires must carry EQUAL and OPPOSITE currents; circuits
where the current flowing out in one wire has no choice but to flow back
in the other wire. You can't use the chassis as your return, or connect
several loads to one wire. For example, you have two long wires running
from your controller to the motor. The high power and arcing brushes
create lots of noise! But the current going out one wire *has* to match
the current coming back in the other wire. So twist or otherwise bundle
them tightly together.
--- Principle Five ---
Suppose the wires are so big, or have so much insulation that you can't
physically twist them or keep them close to each other. Or suppose you
want the ultimate in noise filtering, and want the magnetic fields to
PERFECTLY cancel. Then you use coaxial cable (coax).
Coax has two conductors, which are about the same gauge. The shield is
as heavy as the center conductor, so it can carry substantial current.
This is different from shielded wire, which doesn't carry current in its
shields so the shield is often very thin, sometimes nothing but tinfoil.
coax also can have large spacings between the inner and outer
conductors, so it can handle very high voltages.
When the center and outer conductors carry the same current, coax has
ZERO external magnetic field. It doesn't radiate any noise, and doesn't
pick up any noise from external sources. As an example of how perfect
the cancellation is, coax is the only way to connect a car radio to its
antenna, to receive those sub-microvolt signals in the presence of so
much electrical noise within the car itself.
You could use 2/0 coax to block all your motor noise from escaping from
the wiring; it exists but you don't want to know what it costs per foot!
But you *can* use coax for signal and E-meter leads.
So, taking all the above into acocunt, what do you do with that fancy
triple-shielded cable? Here is how it would be used with an E-meter.
- Treat the load side of the shunt as the negative return or
'ground' for the E-meter hookup.
- Run the shunt sensing wires thru a coaxial cable;
- Center conductor from shunt screw on load side to pin 3 on
the E-meter (which the manual calls the orange wire).
- Outer conductor from shunt screw on load side to pin 2 on
the E-meter (which the manual calls the green wire).
- Run the voltage sensing wires thru a coaxial cable (though a
twisted pair would also be good enough if that' what you had);
- Center conductor from prescaler output red to pin 4 on
E-meter (which the manual calls the blue wire).
- Outer conductor from prescaler output black to pin 1
on the E-meter (which the manual calls the black wire).
- Connect the shield that goes over all the above wires to the
E-meter's 'return' at ONLY ONE END (either the load side of
the shunt, or E-meter pin 1). Since things are crowded at
the E-meter end, I'd connect the shield at the shunt end.
- If you want to connect the third and outermost shield (I wouldn't),
connect it to the real vehicle ground. I wouldn't connect this
unless I was *sure* the cable has adequate insulation between
this shield an all other conductors to withstand 100's of volts.
--- Principle Six ---
> This will have to run in 8 inch square cable and conduit ductway...
Be sure this ductway is *not* iron or steel, or if it is, that it has
some kind of gap between the pieces. You do NOT want a closed ferrous
metal loop or band around these wires. If there is, it forms the iron
core for a transformer!
To understand this, recognize that a toroidal transformer is basically
an iron 'donut' with a hole in the middle. Any wire or metal object that
goes thru the hole in the middle counts as a 'turn'. Thus, any noise
current on ONE wire going thru this hole will be inductively coupled
into all the rest!
Now, recognize that this iron donut could be pounded flat (like a piece
of sheet metal with a hole in it), or stretched out long and thin (like
a piece of pipe), and it will *still* function as a transformer core.
Thus, don't run multiple wires thru a steel pipe (or any shape of closed
tube), or thru a common hole in a piece of sheet steel. The only
exception is when you WANT inductive coupling between them (for
instance, there are transformers built this way).
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
For 6th graders I find that practical examples and demonstrations work
the best. Save the theory for later years.
Marvin Campbell wrote:
> 1. What makes batteries work
Take two different metals and put them in an acid or base solution; for
example, a copper penny and a galvanized (zinc coated) roofing nail
shoved into a lemon. There will be a voltage between them.
The bigger the two metals, the more current you get.
The more of these things you put in series, the higher the voltage you
get.
You can run a solar-powered calculator off a few such lemon-batteries.
What's happening is that the acid is attacking or corroding the metal,
which frees electrons. The metals must be different so one side corrodes
faster. The external wiring (wires to a calculator, for example) carry
the electrons to the other side.
> 2. How do solar panels work
Solar cells have two conductive layers, separated by a very thin
insulating layer. When light hits the top layer, it knocks off electrons
and gives them enough speed to go right thru the thin insulating layer.
They hit the other layer and get stuck there. They have to get back to
the other side by going thru the wiring to the external circuit (like a
calculator).
Does that help?
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
This is off-topic. We're finally cooling off on the off-topic political
ranting.
Please don't start it back up again. Just putting the word "EV" somewhere
in the message doesn't suddenly make it on-topic.
Tim
-----------------
From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Subject: Tickets for parking in EV parking
Date: Tue, 13 Jan 2004 09:26:32 -0800
Might it be possible to modify these for EV use.� Lawrence Rhodes......
Message: 6
�� Date: Mon, 12 Jan 2004 11:19:50 -0500
�� From: RemyC <[EMAIL PROTECTED]>
Subject: Printing out SUV tickets
From:
http://www.baaction.org/SUVticket
Printing out the SUV ticket:
The SUV ticket is in two files that are in PDF format.
The first file is the front side of the ticket
http://www.baaction.org/SUVticket/SUVfront.pdf
and the second file is the backside of the ticket.
http://www.baaction.org/SUVticket/SUVback.pdf
_________________________________________________________________
High-speed users�be more efficient online with the new MSN Premium Internet
Software. http://join.msn.com/?pgmarket=en-us&page=byoa/prem&ST=1
--- End Message ---
--- Begin Message ---
Hi Everyone,
Man, is it cold here in Utah! I've been dreaming of the day when the EV
is running and I get some instant heat from the ceramic heater.
I'm wondering if anyone has tried getting at the existing heater core
through the firewall. I think this would ultimately work out better for
a couple reasons:
1) You could get at it again without having to rip the dash apart
2) You wouldn't have to rip the dash apart in the first place
3) Similiar to number 1, you'd have a permanent access panel
I'm interested to see what the consensus is on this idea.
Thanks,
Ryan
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>
> John Westlund wrote:
> > I've posted here about a month ago with an idea of building
> > a ~$50,000 EV that could do 0-60 in 5, 200 mile range, 120+
> > mph top end
>
> As you know, that is a *very* ambitious set of requirements. It's not
> impossible with a $50,000 budget, but it is still challenging. Pretty
> much everything needs to be done right. It can't be a conversion or
> warmed-over kit car; it will have to be a scratch-built EV, something
> like a clone of the GM EV-1 with Nimh batteries.
>
> Getting 0-60 mph in 5 sec *and* a 200-mile range will require a pretty
> expensive battery pack. Nimh can do it, but they are essentially
> unobtainable.
>
> LiIon might be able to do it, if you took the AC Propulsion approach
> (thousands of laptop cells). But I have my doubts that it is feasible;
> just too dang many parts and connections to be reliable.
>
> I don't think lead-acids can do it. You could get the accelleration *or*
> the range, but not both. They just don't have the necessary storage
> capacity.
>
> That leaves nicads a perhaps your best bet. They can provide the high
> peak current, they (barely) have the energy storage capacity, and they
> are actually available in EV sizes. The price is high, but not as high
> as LiIon or Nimh.
Ultra caps can take care of power requirements for acceleration and
energy dense LiIons or NiZn (or whatever) - of the range.
He need to do the math.
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Oh look, more non-EV crap on the list. I suppose I'll get blamed for
this too.
Your pal,
Meat.
Lawrence Rhodes wrote:
Might it be possible to modify these for EV use. Lawrence Rhodes......
Message: 6
Date: Mon, 12 Jan 2004 11:19:50 -0500
From: RemyC <[EMAIL PROTECTED]>
Subject: Printing out SUV tickets
From:
http://www.baaction.org/SUVticket
Printing out the SUV ticket:
The SUV ticket is in two files that are in PDF format.
The first file is the front side of the ticket
http://www.baaction.org/SUVticket/SUVfront.pdf
and the second file is the backside of the ticket.
http://www.baaction.org/SUVticket/SUVback.pdf
Download both files to your computer by double clicking on the first file
and second file links. To print the files, double click on your downloaded
files to open the Acrobat Reader application. Make sure to select "US
letter" as the page size in the page setup menu. Print the front side first
and then put this printout back in your printer and print the back side
making sure to print on the blank side of the paper.
Although the PDF files are in color, the printouts work with black and
white. Laser printers work the best. Color inkjet printers may blur the
white writing in the red box. Cut out the tickets and you are ready.
Alternatively, you can print out a "master" back and white ticket and take
it to a copy shop and run off a bunch of copies on yellow or pink, or other
ticket colors. You can even have them cut them and get a gum binding for
ticket booklets!
A note about giving tickets:
Remember that this ticket is to be informative, not antagonistic. Choose
your fellow citizen accordingly. For instance, gardeners, carpenters, and
others that need to use trucks for their work will not be very receptive to
the ticket as they have a real need for their trucks. So if you see a truck
loaded down with gardening or construction equipment, choose another for
your education campaign.
I would also avoid the Honda CRV, Subaru Forester, and Toyota RAV4, in that
these cars are cleaner and actually get pretty good gas mileage unlike the
other larger SUVs. Most people do not like tickets so if you are asked what
it is, tell them it is environmental information. Be polite, courteous and
have fun!
Questions:
SUV@ evcl.com
Bay Area Action
265 Moffett Boulevard
Mountain View CA 94043-4723 USA
+1 650 625.1994 Fax +1 650 625.1995
Also go to:
http://www.moles.org/ProjectUnderground/campaigns/suv.shtml
1-800-497-1994 x 230
suvticket@ globalexchange.org
"If broccoli were the number one export from the Middle East, we wouldn't be
invading Iraq"
--- End Message ---
--- Begin Message ---
Here are two URLs that talk about the next level in solar cells:
http://www.sta.com.au/webcontent4.htm
http://www.sta.com.au/download/CSIROBIPV.PDF
----- Original Message -----
From: "Marvin Campbell" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Tuesday, January 13, 2004 11:46 AM
Subject: Educational Outreach
> Dear Folks:
>
> My neighbor talked me into taking our RAV4 EV to the school where she
works
> and showing it to the sixth-graders.
>
> She says they are full of questions about EVs that she can't answer.
>
> Having never done this before I'm seeking help from others who have.
>
> What I would like to find is an easily digestible explanation of:
>
> 1. What makes batteries work
> 2. How do solar panels work
>
> And maybe a good list of links to EV related sites, i.e., history, et.al.
>
> If anybody out there has any experience conveying EV awareness to 11/12
> year-olds and would like to share, please help.
>
> Thanks!
>
> J. Marvin Campbell
> Culver City, CA
>
> PS: I'm trying to wrest our 7 year-old away from my wife long enough for a
> roadtrip to LV on the 24th to show him some REAL EVs!
>
>
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
> Chuck Hursch wrote:
> >
> > Otmar wrote:
> > > At 10:57 AM -0500 1/12/04, fred whitridge wrote:
> > > >Lee, Otmar, Mike, Shari (and other pre-charge experts):
> > >
> > > ........
> > >
> > > >So my questions:
> > > >1) How bad is it not to pre-charge? I note the pitting of
the
> > main
> > > >contactor contacts but what is it doing to the controller?
> > >
> > > It is putting some pretty high current pulses on the
capacitors
> > in
> > > the controller. How bad this is I don't know. Auburn
claimed
> > that it
> > > could cause their caps to fail. I've seen 108v curtis
powered
> > cars
> > > run for more than 10 years with no precharging. I've seen
> > others blow
> > > for unknown reasons that might have been related to the
lack of
> > > precharge.
> >
> > I have a 1231C in my 96V Rabbit, which was changed from the
> > standard VoltsRabbit setup. Electrically, it's VoltsRabbit
with
> > a 1231C enhancement; however, positionally the
> > controller/contactor scene is quite different. The standard
> > VoltsRabbit setup has the contactor controlled by the
accelerator
> > pedal, so the contactor (and the controller) see a lot of
on/off.
> > I do try to keep the contactor closed if I can, but if I have
to
> > use the brake, well then, my foot comes off the accelerator.
> > Clunk. I get tired of the clack/clunk, and I do wonder about
the
> > wear and tear.
> >
> > The 1231C has been in there since 1996, and remains happy as
a
> > clam. No precharge circuit. My contactor has had some
> > problems - about every two years for the last four or five,
it
> > will start getting into this mode of not closing, so the
trick I
> > learned is to just leave the accelerator pedal slightly down,
so
> > it should close, and it eventually does in five minutes or
so.
> > Once closed, things usually open and close ok for that run.
I
> > assume it warms up enough to overcome the crud in the shaft
where
> > the contactor assembly slides. A good flush with WD40 seems
to
> > cure the problem for a couple of years. The contactor is on
its
> > side.
> >
> > I'd like to get a pre-charge circuit set up (just one of a
> > million things to do to that car...), and I have also thought
> > about going to key-switch control of the contactor. However,
my
> > recent experience with speed surges (last Oct or so) leaves
me
> > feeling like it might almost be better to keep the control of
the
> > contactor with the accelerator pedal (aka deadman). It's
faster
> > to drop the foot off the accelerator pedal if something goes
> > wrong than it is to get the left foot pushing down on the
clutch
> > (and then unloading the motor). However, the surges have
been
> > fixed, but not forgotten...
>
> Are you using a DC/DC converter, or just running off a 12v
accessory
> battery? If there's no DC/DC converter and you have a lot of
12v loads
> on (headlights, heater fan blower, windshield wipers, etc.)
then you may
> be pulling the 12v down so far that the contactor won't pull in
when its
> coil is hot.
I have a DC-DC converter, and the voltage is at about 14.2V at
the accessory battery. The sticky contactor problem would happen
usually after the car sat for awhile in the cool, damp, evening
air at work. Hop in the car, turn on the keyswitch, press down a
bit on the accelerator pedal, and no clunk of the contactor
closing. Keep the accelerator pressed down and after five or ten
minutes, would get the closing clunk. After that, the contactor
would respond to the accelerator pedal pretty reliably, although
at its worst there were some delays even after the car had been
underway. This kept my blood pressure raised slightly, since I
had to play the game of ensuring that the contactor was ready to
go at the intersection light, so that I wouldn't be stuck for a
few seconds in front of a line of impatient gas car drivers.
My theory was that during the wait I was heating up the
contactor, thus softening the goo, rust or whatever it was that
holding the contactor open down in the shaft, and eventually the
coil would overcome the goo and close.
I've had thoughts about disassembling the contactor and cleaning
the shaft(s) out. An Albright can't be that complicated, can it?
>
> I had this problem with my ComutaVan. The solution was to
>
> a) Improve the 12v wiring. With 12.0v at the battery, I only
had 10.2v
> at the contactor coil (a 1.8v drop) due to all the cheap
wire,
> switches, connectors, and fuses in the circuit. Rewiring it
with
> heavier wire and fewer connectors brought it up to 11.5v (a
0.5v
> drop).
Yes, I do have quite a voltage drop to the contactor. As in your
case, there's lots between the DC-DC convertor and the contactor,
including probably a good four to five feet of 16-ga wire or
thinner (18ga?), since these two pieces are on opposite sides of
the engine bay. I believe that the contactor is seeing on the
order of 11-12V (but I'd have to check the log book, it could be
closer to 10V) with the 1A draw to hold the contactor's coil
closed. Rewiring at least the last couple of feet to the
contactor (the easy part) with 12ga wire, and yes, nice shiny new
connectors, would be a good thing.
>
> b) Added a 'slugger' circuit in series with the coil. The
contactor
> coil draws so much current that it gets hot. The heat raises
the
> coil's resistance so it needs more voltage to pull in when
hot.
> I added a 'slugger' circuit; a 10w resistor of the same
value as
> the coil (about 7 ohms) with a 4700uF 16vdc capacitor in
parallel,
> and this combination in series with the coil. When 12v is
first
> applied, the capacitor is at 0 volts, so the coil gets the
full
> 12v. Then the capacitor charges, and the resistor limits the
coil
> voltage to about 6v. This is enough to hold it pulled in.
The coil
> is now dissipating only 1/4th the power, and runs far
cooler.
I'll keep this idea for reference and perhaps add it in when I do
the rewire above. I was once quite surprised (in the first year
or two that I had the car) how warm that contactor becomes.
About 12W source; 3W would be nicer. Hey, I wonder how far that
will extend my range ;->, but all these things add up... Looking
at this after proofreading pass, you're still dissipating the
wattage, but now in the resistor, correct? Was your contactor
controlled by the accelerator pedal (click/clack all the time) or
by the keyswitch (one clunk at start)?
Chuck
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
http://www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
http://www.geocities.com/chursch/bizcard.bmp
--- End Message ---
--- Begin Message ---
Hi David,
The main concern is room for the second contactor and more
cabling; I'd also have concerns about doubling the component
count. When I upgraded to the 1231C from the standard
VoltsRabbit 1221B controller (1221B on the VoltsRabbit aluminum
heatsink with no fan got hot, and two of these controllers either
failed or otherwise had weird symptoms on my apt hill), I had the
idea of changing the controller orientation around so I could get
two big fans on top of the controller. This meant the contactor
had to go underneath the controller, between the bumper shock
tube and the fender. It was simply amazing how little space
there was between the suspension strut tower, the front of the
car (headlights), and sideways: the fender and the edge of the
battery pack, and also top to bottom. The original idea of
putting in an Auburn went out the door, although it might have
been do-able if the potbox had moved elsewhere (which I think it
will eventually do anyways). The 1231C, the contactor, and 2/0
cabling all took on LARGE proportions. Eventually, I got it all
worked out. The controller can be removed in five to ten
minutes, depending on how "practised" I am at it. The contactor
has not been pulled since 1996, and the space is a lot tighter,
with all the cables and such. So I don't see how I could get
another Albright-sized contactor in there. There is a picture
from just after I got it put together back in 1996 at
http://www.geocities.com/nbeaa/images/61a.jpg. The scene has
improved since then, but it's basically the same. All the rags
to the side covered the batteries, since the posts were exposed
on the first battery pack.
Thanks,
Chuck
----- Original Message -----
From: "David Brandt" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, January 12, 2004 2:18 PM
Subject: RE: Pre-charge questions
> Chuck, what about using a second contactor? The first in the
line would
> open/close based on keyswitch position only. The next
downstream (closer to
> the controller) would be bridged by a precharge resistor, and
would be
> controlled by keyswitch current interrupted by the accelerator
pedal. No
> appreciable current would flow during stop, but charge would be
maintained
> through the resistor. Any controller fault at stop would draw
enough
> current to blow the resistor.
>
> -----Original Message-----
> From: Chuck Hursch [mailto:[EMAIL PROTECTED]
> Sent: Monday, January 12, 2004 3:09 PM
> To: [EMAIL PROTECTED]
> Subject: Re: Pre-charge questions
>
>
> Otmar wrote:
> > At 10:57 AM -0500 1/12/04, fred whitridge wrote:
> > >Lee, Otmar, Mike, Shari (and other pre-charge experts):
> >
> > ........
> >
> > >So my questions:
> > >1) How bad is it not to pre-charge? I note the pitting of
the
> main
> > >contactor contacts but what is it doing to the controller?
> >
> > It is putting some pretty high current pulses on the
capacitors
> in
> > the controller. How bad this is I don't know. Auburn claimed
> that it
> > could cause their caps to fail. I've seen 108v curtis powered
> cars
> > run for more than 10 years with no precharging. I've seen
> others blow
> > for unknown reasons that might have been related to the lack
of
> > precharge.
>
> I have a 1231C in my 96V Rabbit, which was changed from the
> standard VoltsRabbit setup. Electrically, it's VoltsRabbit
with
> a 1231C enhancement; however, positionally the
> controller/contactor scene is quite different. The standard
> VoltsRabbit setup has the contactor controlled by the
accelerator
> pedal, so the contactor (and the controller) see a lot of
on/off.
> I do try to keep the contactor closed if I can, but if I have
to
> use the brake, well then, my foot comes off the accelerator.
> Clunk. I get tired of the clack/clunk, and I do wonder about
the
> wear and tear.
>
> The 1231C has been in there since 1996, and remains happy as a
> clam. No precharge circuit. My contactor has had some
> problems - about every two years for the last four or five, it
> will start getting into this mode of not closing, so the trick
I
> learned is to just leave the accelerator pedal slightly down,
so
> it should close, and it eventually does in five minutes or so.
> Once closed, things usually open and close ok for that run. I
> assume it warms up enough to overcome the crud in the shaft
where
> the contactor assembly slides. A good flush with WD40 seems to
> cure the problem for a couple of years. The contactor is on
its
> side.
>
> I'd like to get a pre-charge circuit set up (just one of a
> million things to do to that car...), and I have also thought
> about going to key-switch control of the contactor. However,
my
> recent experience with speed surges (last Oct or so) leaves me
> feeling like it might almost be better to keep the control of
the
> contactor with the accelerator pedal (aka deadman). It's
faster
> to drop the foot off the accelerator pedal if something goes
> wrong than it is to get the left foot pushing down on the
clutch
> (and then unloading the motor). However, the surges have been
> fixed, but not forgotten...
>
> Chuck
>
> Chuck Hursch
> Larkspur, CA
> NBEAA treasurer and webmaster
> http://www.geocities.com/nbeaa
> http://www.austinev.org/evalbum/339.html
> http://www.geocities.com/chursch/bizcard.bmp
--- End Message ---
--- Begin Message ---
Hello:
We've been having freezing and sub freezing weather here in Connecticut
and I've been eager to get some on-road experience in these temps with
my 10 NiZn batteries. At present I have 10 NiZn MB80's in the rear box,
and 10 Optima YT's in the front. Either (or both) strings can be
selected via contactors. My car has been sitting since before Christmas
and i returned from vacation only to suffer a blown fuse which took a
while to track down. I took a brief ride last night and a longer one
tonight and was NOT pleased with the results. The voltage sag is deeper
and quicker than in warm weather. Perhaps this is because the car has
been sitting. We shall see as colder weather is on the way. I'm
disappointed since I had expected NiZn (like its cousing NiCd) to be a
superior cold weather performer.
The sag was so bad that i had to parallel the Optimas for some hills. I
chalked this up to an undercharged pack last night but the same can't be
said for today.
Temps are quite interesting. On tonights ride ambient was 5.0C in the
garage and the pack was at 2C. After a quick 9 mile run, and 17.1 Ah
out of the NiZn pack (plus a bit from the YT's for the time they were
paralleled, alas amount not written down but probably 2-3Ah) pack temp
was up to10C and ambient had dropped half a degree to 4.5C. A half
hour later with the batts on charge, pack temp was at 17C and ambient
was down to 4C.
These sort of temps indicate the internal resistance and show the
enormous heat generation of these batts. i would have thought the low
ambient would have held this down. The battery chemistry is endothermic
on charge so the temp increase was the "drift" up fromt he discharge
phase, which is what I'd seen on the cycler and in the car with late
summer temps.
All is not lost: I have the second 10 batts waiting to be installed in
the front when i remove the Optima's. if the second, paralleled, string
doesn't help matters I could always go back to the current PbA/NiZn
hybrid setup I have now, perhaps with some perky Orbitals rather than
the doggy Optimas which are upfront right now.
Colder weather and hopefully more experience as the week unfolds....
--- End Message ---
--- Begin Message ---
I just read Patrick Bedard's column in the Jan 2004 issue of Car &
Driver magazine ("The buyers have spoken: Forget electric cars"). Now, I
know these guys are completely clueless about electric cars and openly
hostile to them. However, I wanted a reality check to see if his
statistics are real or invented.
To paraphrase, he said Toyota initially offered its Prius as
internet-only sales to find out who the customers really were. They knew
their dealers were clueless, and would only try to steer people away
from the Prius and toward a high-profit SUV. They sold about 18,000 cars
in 18 months. That proved there was a demand, so they increased
production and kept selling them. [That part is mostly true, from my
limited experience.]
But he goes on to say that Toyota then decided to try the same strategy
with the RAV4 EV. They offered it for sale on the internet. They were
selling an SUV, which should have sold better than the Prius. They even
offered dealers who sold a RAV4 EV a $2000 profit margin above the
Prius. He says the results were negligible sales; only 47 cars in 2
weeks, 213 over 6 months. This proves that nobody wants EVs.
Now for my question; is this true? Did Toyota offer their RAV4-EVs like
this, and was it a sales flop?
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
I remember checking out a Toyota web site that was on a link you had to be
told. It was to put your name on a list to lease the RAV 4EV but on further
reading was only available to people living in selected areas of California,
much like the GM EV1. I did put my name on the list to be informed if they
were ever offered in my area but didn't hear back :-(
Lawrence
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: January 13, 2004 5:52 PM
To: EVlist - Electric Vehicle Discussion List
Subject: Article in Jan 2004 Car & Driver magazine
I just read Patrick Bedard's column in the Jan 2004 issue of Car &
Driver magazine ("The buyers have spoken: Forget electric cars"). Now, I
know these guys are completely clueless about electric cars and openly
hostile to them. However, I wanted a reality check to see if his
statistics are real or invented.
To paraphrase, he said Toyota initially offered its Prius as
internet-only sales to find out who the customers really were. They knew
their dealers were clueless, and would only try to steer people away
from the Prius and toward a high-profit SUV. They sold about 18,000 cars
in 18 months. That proved there was a demand, so they increased
production and kept selling them. [That part is mostly true, from my
limited experience.]
But he goes on to say that Toyota then decided to try the same strategy
with the RAV4 EV. They offered it for sale on the internet. They were
selling an SUV, which should have sold better than the Prius. They even
offered dealers who sold a RAV4 EV a $2000 profit margin above the
Prius. He says the results were negligible sales; only 47 cars in 2
weeks, 213 over 6 months. This proves that nobody wants EVs.
Now for my question; is this true? Did Toyota offer their RAV4-EVs like
this, and was it a sales flop?
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
> Ultra caps can take care of power requirements for acceleration and
> energy dense LiIons or NiZn (or whatever) - of the range.
> He need to do the math.
Hmm, yes; that's another possibility -- some kind of hybrid battery
pack, with one set for the high peak power and another set for the long
range. Ultracapacitors and LiIons might do it.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Chuck Hursch wrote:
>
> Lee Hart wrote:
> > Chuck Hursch wrote:
> > >
> > > Otmar wrote:
> > > > At 10:57 AM -0500 1/12/04, fred whitridge wrote:
> > > > >Lee, Otmar, Mike, Shari (and other pre-charge experts):
> > > >
> > > > ........
> > > >
> > > > >So my questions:
> > > > >1) How bad is it not to pre-charge? I note the pitting of
> the
> > > main
> > > > >contactor contacts but what is it doing to the controller?
> > > >
> > > > It is putting some pretty high current pulses on the
> capacitors
> > > in
> > > > the controller. How bad this is I don't know. Auburn
> claimed
> > > that it
> > > > could cause their caps to fail. I've seen 108v curtis
> powered
> > > cars
> > > > run for more than 10 years with no precharging. I've seen
> > > others blow
> > > > for unknown reasons that might have been related to the
> lack of
> > > > precharge.
> > >
> > > I have a 1231C in my 96V Rabbit, which was changed from the
> > > standard VoltsRabbit setup. Electrically, it's VoltsRabbit
> with
> > > a 1231C enhancement; however, positionally the
> > > controller/contactor scene is quite different. The standard
> > > VoltsRabbit setup has the contactor controlled by the
> accelerator
> > > pedal, so the contactor (and the controller) see a lot of
> on/off.
> > > I do try to keep the contactor closed if I can, but if I have
> to
> > > use the brake, well then, my foot comes off the accelerator.
> > > Clunk. I get tired of the clack/clunk, and I do wonder about
> the
> > > wear and tear.
> > >
> > > The 1231C has been in there since 1996, and remains happy as
> a
> > > clam. No precharge circuit. My contactor has had some
> > > problems - about every two years for the last four or five,
> it
> > > will start getting into this mode of not closing, so the
> trick I
> > > learned is to just leave the accelerator pedal slightly down,
> so
> > > it should close, and it eventually does in five minutes or
> so.
> > > Once closed, things usually open and close ok for that run.
> I
> > > assume it warms up enough to overcome the crud in the shaft
> where
> > > the contactor assembly slides. A good flush with WD40 seems
> to
> > > cure the problem for a couple of years. The contactor is on
> its
> > > side.
> > >
> > > I'd like to get a pre-charge circuit set up (just one of a
> > > million things to do to that car...), and I have also thought
> > > about going to key-switch control of the contactor. However,
> my
> > > recent experience with speed surges (last Oct or so) leaves
> me
> > > feeling like it might almost be better to keep the control of
> the
> > > contactor with the accelerator pedal (aka deadman). It's
> faster
> > > to drop the foot off the accelerator pedal if something goes
> > > wrong than it is to get the left foot pushing down on the
> clutch
> > > (and then unloading the motor). However, the surges have
> been
> > > fixed, but not forgotten...
> >
> > Are you using a DC/DC converter, or just running off a 12v
> accessory
> > battery? If there's no DC/DC converter and you have a lot of
> 12v loads
> > on (headlights, heater fan blower, windshield wipers, etc.)
> then you may
> > be pulling the 12v down so far that the contactor won't pull in
> when its
> > coil is hot.
>
> I have a DC-DC converter, and the voltage is at about 14.2V at
> the accessory battery. The sticky contactor problem would happen
> usually after the car sat for awhile in the cool, damp, evening
> air at work. Hop in the car, turn on the keyswitch, press down a
> bit on the accelerator pedal, and no clunk of the contactor
> closing. Keep the accelerator pressed down and after five or ten
> minutes, would get the closing clunk. After that, the contactor
> would respond to the accelerator pedal pretty reliably, although
> at its worst there were some delays even after the car had been
> underway. This kept my blood pressure raised slightly, since I
> had to play the game of ensuring that the contactor was ready to
> go at the intersection light, so that I wouldn't be stuck for a
> few seconds in front of a line of impatient gas car drivers.
>
> My theory was that during the wait I was heating up the
> contactor, thus softening the goo, rust or whatever it was that
> holding the contactor open down in the shaft, and eventually the
> coil would overcome the goo and close.
>
> I've had thoughts about disassembling the contactor and cleaning
> the shaft(s) out. An Albright can't be that complicated, can it?
> >
> > I had this problem with my ComutaVan. The solution was to
> >
> > a) Improve the 12v wiring. With 12.0v at the battery, I only
> had 10.2v
> > at the contactor coil (a 1.8v drop) due to all the cheap
> wire,
> > switches, connectors, and fuses in the circuit. Rewiring it
> with
> > heavier wire and fewer connectors brought it up to 11.5v (a
> 0.5v
> > drop).
>
> Yes, I do have quite a voltage drop to the contactor. As in your
> case, there's lots between the DC-DC convertor and the contactor,
> including probably a good four to five feet of 16-ga wire or
> thinner (18ga?), since these two pieces are on opposite sides of
> the engine bay. I believe that the contactor is seeing on the
> order of 11-12V (but I'd have to check the log book, it could be
> closer to 10V) with the 1A draw to hold the contactor's coil
> closed. Rewiring at least the last couple of feet to the
> contactor (the easy part) with 12ga wire, and yes, nice shiny new
> connectors, would be a good thing.
> >
> > b) Added a 'slugger' circuit in series with the coil. The
> contactor
> > coil draws so much current that it gets hot. The heat raises
> the
> > coil's resistance so it needs more voltage to pull in when
> hot.
> > I added a 'slugger' circuit; a 10w resistor of the same
> value as
> > the coil (about 7 ohms) with a 4700uF 16vdc capacitor in
> parallel,
> > and this combination in series with the coil. When 12v is
> first
> > applied, the capacitor is at 0 volts, so the coil gets the
> full
> > 12v. Then the capacitor charges, and the resistor limits the
> coil
> > voltage to about 6v. This is enough to hold it pulled in.
> The coil
> > is now dissipating only 1/4th the power, and runs far
> cooler.
>
> I was once quite surprised (in the first year or two that I had the
> car) how warm that contactor becomes.
The 'slugger' really becomes necessary if you are using 12v contactors
and have your DC/DC over 14v and have really good wiring with low
voltage drops.
> you're still dissipating the wattage, but now in the resistor,
> correct?
When you add the resistor in series, the total power goes down. If your
contactor coil is 12 ohms for example, it draws 12v x 1a = 12w. If you
put a 12 ohm resistor in series, the total resistance is now 24 ohms,
and draws 0.5 amps. The total power (resistor + contactor coil) is now
12v x 0.5a = 6 watts; 3 watts dissipated in the coil and 3 watts in the
resistor.
> Was your contactor controlled by the accelerator pedal (click/clack
> all the time) or by the keyswitch (one clunk at start)?
The ComutaVan had a contactor controller, so they operated every time I
pushed the pedal.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
