EV Digest 3826
Topics covered in this issue include:
1) Re: EV Generators
by "Rich Rudman" <[EMAIL PROTECTED]>
2) Re: Ultracap cell balancing
by Evan Tuer <[EMAIL PROTECTED]>
3) Re: Broken seal on end of Curtis????
by Lee Hart <[EMAIL PROTECTED]>
4) Steve's Fast EV, was , Diablo conversion +, Hurricanes, EV's
by jerry dycus <[EMAIL PROTECTED]>
5) RE: Deafscooter's 1 St place on Route 66 Rally 9/25
by "Roger Stockton" <[EMAIL PROTECTED]>
6) Re: Woodburn 2004
by "Roderick Wilde" <[EMAIL PROTECTED]>
7) Re: Woodburn 2004
by "Dave" <[EMAIL PROTECTED]>
8) Re: +, Hurricanes, mountains on the move
by "Rich Rudman" <[EMAIL PROTECTED]>
9) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by Victor Tikhonov <[EMAIL PROTECTED]>
10) Re: Contactor voltage rating -- What's the deal?
by Eric Poulsen <[EMAIL PROTECTED]>
11) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by Victor Tikhonov <[EMAIL PROTECTED]>
12) Re: The first EV sports car
by "Rich Rudman" <[EMAIL PROTECTED]>
13) Re: Calculating size of Capacitor for Electric PS Pump
by Victor Tikhonov <[EMAIL PROTECTED]>
14) Custom Transformers
by Neon John <[EMAIL PROTECTED]>
15) Re: Ultracap cell balancing
by Victor Tikhonov <[EMAIL PROTECTED]>
16) Re: The first EV sports car
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Ultracap cell balancing
by Lee Hart <[EMAIL PROTECTED]>
18) Mellow Yellow lives on... but which batteries?
by Richard Bebbington <[EMAIL PROTECTED]>
19) Circuit Breakers, Fuses and switches
by "Don Cameron" <[EMAIL PROTECTED]>
20) Re: Ultracap cell balancing
by Victor Tikhonov <[EMAIL PROTECTED]>
--- Begin Message ---
----- Original Message -----
From: "Doug Hartley" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, September 28, 2004 8:34 PM
Subject: EV Generators
> Bill Dennis wrote:
> > Does the generator hook
> > up to the battery pack looking like just another power source in
parallel?
> Yes, with a circuit breaker for protection and disconnect when working on
> it, and an Ammeter shunt in series with one of the connections.
>
> I am using eCycle Permanent Magnet Brushless DC motors spun by Honda
> engines, with a 3-phase diode bridge to produce DC directly, like an
> alternator. Using a 120VAC single phase standard home power generator
would
> not be as efficient, nor allow the voltage and current output to be
adjusted
> directly with governed engine RPM.
>
Doug...
You need some form of voltage regulation or.... you are going to fry
batteries. Weather it's a feedback loop to the Ice engine govenor control or
solid state SCR voltage regulation of the
BLDC phase leads.
Without some sort of controls beside RPM of the engine. This is Worse
that a Variac for AGM battery service work.
What kind of control do you have??? or any?
You should beable to do boost control of the output of that BLDC. Using the
larger higher voltage stator will help, but even with the lower wattage
stage, using boost control would allow you to get useable power from the
phases without having to run the rpm up and down.
--- End Message ---
--- Begin Message ---
On Wed, 29 Sep 2004 18:05:13 +0200, Emil Naepflein
<[EMAIL PROTECTED]> wrote:
> In
> http://www.nesscap.com/prod/Articles/JPS_Vol114_2003_pp366-373_NESSCAP.PDF
> you find more information about Ultracaps in vehicle applications.
>
> So the effort for balancing UltraCaps is nearly twice as high as with
> lithium cells. This drives the costs considerably up.
That's interesting. I'm not sure I agree that the effort for
balancing is twice as high, I use pretty much the same approach as
this for Li-Ion.
But, I hate to think what would happen if a couple of the caps went
short-circuit. Would the rest follow, christmas-tree bulb style? Or
hand-grenade style? :?
--- End Message ---
--- Begin Message ---
Rick wrote:
> Hi Lee, thanks for the reply... I happen to have formed the opinion
> that Curtis would love to sell more controllers.
I think the explanation is more basic. Manufacturers spend as little as
possible on weatherproofing, because customers *pay* as little as
possible. Most consumers don't realize that water will destroy
electronics. They *buy* stuff with poor weatherproofing and use it
outdoors. When it fails, they don't complain; they just buy a new one or
pay an exhorbitant repair bill. This rewards the manufacturer, so they
keep right on building it to fail!
But, keeping water out of electronics in an automotive environment is
very difficult. Things that seem reasonable don't actually work.
Conformally coating PC boards only slows water down (fails in a year
instead of a week). The different rates of thermal expansion between
materials means that cracks form as soon as the temperature is cycled
up/down. The cracks let air inside the supposedly "sealed" case. As
atmospheric pressure goes up/down, the case "breathes" and pulls in
moisture.
It is common to open a Curtis controller for repair, and find
significant amounts of water inside. The scenario goes like this: The
case develops a crack. As the controller gets hot and later cools, the
air inside expands and contracts. So the case "inhales" and "exhales"
outside air through the cracks. The air pulled in contains water. This
water condenses inside, and causes shorts and corrosion.
> I expect the heat of shipping inside hot trucks wrought havoc here.
I doubt that a single hot/cold cycle would do more than create some
microscopic cracks. Repetitive cycling makes these microcracks grow and
spread, until they become large enough to see and cause problems.
> so I'll hope that I can find something to stick it down with that
> will actually form a better seal and locate the controller inside
> a forced vented box.
There *are* a number of techniques that can truly make it water-tight.
(Dumping potting compound into the ends isn't one of them).
1. Hermetic sealing
This means totally airtight, fused (melted together) seals using glass,
metal, and ceramics. No plastics or rubber; they are porous, and leak
over time. Hermetic sealing has an essentially ZERO leak rate, and will
keep contaminants out for 100+years.
Vacuum tubes, light bulbs, and metal-ceramic integrated circuits are
examples of hermetically sealed devices. But, it would be impractical to
apply this method to a Curtis controller (the manufacturer could do it,
but you and I can't retrofit it).
2. Encapsulation ("potting")
This means completely surrounding or submerging the circuits with some
moisture resistant material; plastic, glue, oil, wax, etc. These
materials allow moisture to slowly creep through them; but they are so
thick that it takes a long time for the moisture to reach the circuits
(how long depends on the thickness). Encapsulation works for decades.
Most under-hood electronics in cars are encapsulated. Most integrated
circuits are encapsulated in plastic/epoxy cases.
Encapsulating a Curtis controller is fairly easy. Remove the screws in
the side for adjusting the internal pots, and fill the case with a
potting compound. The potting compound will "set", so it won't leak even
if there are already cracks and leaks in the case. If you ever want to
get it apart again for repairs, use a potting compound that can be
melted or disolved with some solvent.
Oil works if the case is already truly watertight, and if it *stays*
that way (not likely). But, you can improve the end seals (with silicone
rubber, for example) so the case will hold the oil indefinitely. Since
oil expands/contracts at a different rate than the case, you'll need a
little air space somewhere to handle expansion/contraction.
3. Conformal coating
This means putting a thin coating of some moisture-resistant material
(acrylic, varnish, epoxy, silicone rubber, etc.) over the outer surface
of the circuit to be protected. It is basically a cheaper, simpler
version of encapsulation. Conformal coatings only delay moisture
penetration; they don't stop it. The coatings are too thin, and there
are always pinholes and cracks. Really thin, almost invisible coatings
are only good for short-term, temporary exposure to water. Thicker
coatings can survive moisture exposure for a few years.
Some Curtis controllers have conformally coated circuit boards, and use
blobs of silicone rubber on certain key parts. You can add these
yourself if you don't mind taking the controller apart. This can work if
you live in a basically dry area, where moisture exposure is rare.
> The ad stated very clearly for PM D.C. motors only, so that was
> the intended use, but why use one H.P when you can have 5 or more
> on the same project just by swapping motors?
There isn't much you can do to a DC motor controller to make it work for
PM motors *only*, so it is almost certain to work with a series motor
equally well. The exceptions have to do with controllers that are trying
to do reversing, regenerative braking, or precise speed or torque
control.
> I bet I'd need a MEGGER (SP?) to measure the inductance? Is there
> another way? How about an MFJ antenna analyzer that will measure
> inductance of coils and baluns for amatuer radio use? Probably
> use the lowest frequency, which would be 1.8 MHz?
A "megger" is a megohm-meter, a meter for measuring very high
resistances, up in the megohms.
You measure inductance with an inductance meter. Inductance changes
slightly with frequency, so it is best to measure it somewhere near the
frequency that the controller uses (audio frequencies). It's not so much
that the inductance itself changes with frequencies; it's that the
inductance gets masked by other resistive and capacitive effects so the
meters can't measure it accurately.
Lots of digital multimeters include inductance scales, so you can use
them -- they measure inductance at audio frequencies, which is about
right for motors. You can use meters that measure at high frequencies
(like 1.8 MHz), but the readings will be in error due to capacitance in
the motor winding becoming significant.
Note that inductance also changes with current. This effect is of
particular importance for motors. Most meters can't measure inductance
at anything other than very low currents.
> Is there a way to block the controller from getting reverse
> polarity from any backwards motion that might accidentally happen
> on slight inclines? What rating/type of diode would you recommend
> and where would you place it in the circuit?
Assuming you are using a typical MOSFET-diode controller (like the
Curtis), there is nothing the controller can do to prevent it. Likewise,
the motor *will* work as a generator, whether you like it or not.
A series motor becomes a generator when you turn it BACKWARDS. The
generated current is in the same direction as the forward current, but
the voltage is reversed. So, diodes in series with the motor or battery
won't help. The simplest fix is to add a contactor to break the motor
circuit. Or, add a reversing contactor to electrically reverse the
current (so the controller can block or control it).
A PM motor becomes a generator just by pushing it faster than it already
wants to run. So, you get the above effect, *plus* it will generate if
you roll down a hill too fast in the same direction you were driving.
Here, the only fix is a contactor to open the motor wires.
--
"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 ---
Hi Steve and All,
--- Steve Clunn <[EMAIL PROTECTED]> wrote:
Glad to hear your are OK! I was worried as I
know the power of destruction you faced!
>
> ----- Original Message -----
> From: "jerry dycus" <
> > I'm having to write fast because my power is
> out
> > for more than 30 hrs now and it doesn't look like
> it
> > will be restored quickly as so many other places
> are
> > still without power around the SE US making
> resources
> > thin.
>
> Power that comes out of the wall in your house?????
> what is that.???
It's rough, but it makes life intereting, doesn't
it? ;^))
>
> > But the EV's I have are still supplying me
> with
> > lights, TV, computer, refrig and most important,
> fans.
>
> me to again , but no refrig . still had all the
> stuff out so set up wasn't
> that hard, and now I can have batteries in the house
> without the wife
> gettting mad.
1 of the few benefits!!
>
>
>
> > It hit worse of all right on Steve Clunn
> again a
> > second time in Ft Pierce on the east coast, he's
> had
> > some really bad luck, hope he's ok..
> I've been reading the Diablo kit car conversion post
> and as some may
> remember I'm doing a 2 motor conversion for Paul
> www.paulsexotics who makes fiberglass kit cars .
> The 912 has been sitting
> in my yard since the beginning of the summer. I have
> the 2 8 " motors in
> and battery boxes in the back done ( the car will
> hold 25 excides easy).
> Paul is planning on putting his Porsche GT1 body on
What kind of chassis are you using?
Does the Porcshe 924-928-944 use a seperate
chassis, frame that could be used?
> I talk to a lot of people that are thinking along
> the lines that Simon might
> be thinking , and that is to make something "better"
> than some gas car they
> like. I try to tell them that EV's have there own
> type of magic, something
> that surpasses the speed thing , the cost little to
> drive thing , Something
> that they have no idea about , even a "plane Jane"
> conversion can give you
> that EV grin . The fun of building and learning
> to care for an EV is hard
> to convey .
Few want to learn, do anymore, just turn key
without any work, learning. But they will be the ones
screwed in the near future!!
jerry dycus
> Steve Clunn
>
>
>
_______________________________
Do you Yahoo!?
Declare Yourself - Register online to vote today!
http://vote.yahoo.com
--- End Message ---
--- Begin Message ---
Lawrence Rhodes [mailto:[EMAIL PROTECTED] wrote:
> Scooters go 18mph. These guys all modify them.
~All~ stock gas and electric scooters go 18MPH? ;^>
Modified or not, I just would like to know what sort of performance the
scooters he "raced" against was. Without this context, reports of his
scooter's performance are much less meaningful.
> He is racing
> against non stock scooters with a non stock electric scooter.
This appears to have been a "rally" not a "race". Unfortunately, in
addition to not finding any record of any participant's performance on
the AMMRA site I also didn't find any mention of what (if any)
competition actually took place at this event.
> If you had attended one of the scooter meets and seen one or
> more of Craigs creations you would know better.
Agreed, however, like many on this list, I don't happen to live in
California and therefore it is unfortunately quite likely that I will
never meet Craig or see one of his creations in person.
Extraordinary claims are made for Craig's creations and extraordinary
claims require extraordinary proof.
> In the last meet he came in second
> by a few yards with a smaller pack. I guess he figured over
> kill was better than second place.
Since he appears to have been alone in his class this time, it was
impossible for him to come in second. ;^>
I'm not faulting him for using a larger pack, etc., I am just trying to
get a feel for how his performance compared to that of the other
participants and to understand exactly who he was competing against.
First in a field of one is meaningless.
He had to swap packs to complete the rally; were the gassers allowed to
refuel? Could they have completed the rally at higher speed if they
were allowed to refuel (i.e. did they have to drive more conservatively
than Craig because of having to complete the rally on a single tank of
fuel)?
If the answer to my question is that nobody here knows what the
performance of the other participants was for comparison, that's OK
(unfortunate, but OK); just say so.
Thanks,
Roger.
--- End Message ---
--- Begin Message ---
Dave, I had an epiphany while riding to work on my electric board scooter
which I do daily. It costs less than one half a kilowatt hour to fill up
which amounts to about three cents a fill up with our electricity rates. It
got me to thinking that most of the energy used to transport people is not
used to transport people. Most of the energy is used to transport the
vehicle. Since it is the person that wants to go someplace and not the
vehicle it made me feel like when I'm driving an ICE vehicle my labor is
going to support some dumb vehicle which could care less how much I spend on
it. Just a different perspective from my twisted mind.
Roderick Wilde
"Suck Amps EV Racing"
www.suckamps.com
----- Original Message -----
From: "Dave" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, September 28, 2004 11:16 PM
Subject: Re: Woodburn 2004
Thanks Rod~
That show was what got me interested in EVs. I can see the writing on the
wall, and it says that fossil fuels for vehicles is going the way of the
dinosaurs. I also am tired of: a) Funding OPEC and the people they
support, b) Watching the cost per mile increase every week while my income
stays the same (VA disability and Military retirement), c) Paying for SMOG
tests and catalytic converters and tune-ups etc just for the privilege of
getting from point "A" to point "B", d) seeing the air and water of the
earth turned into septic wastelands from ICE by-products. I want to build
or buy my own EV of some sort, but I am still a novice about the science.
That is why I lurk here, listening to you guys hash out the problems,
share your experience and crow over the victories. In my mind, it is the
right thing to do. Ok, back to lurking
David C. Wilker Jr.
USAF (RET)
----- Original Message -----
From: "Roderick Wilde" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, September 28, 2004 10:36 PM
Subject: Re: Woodburn 2004
Dave, You are right on! The postal van was actually made at the factory
as an electric but to try to give the audenciece a feel for what it takes
to do a conversion we faked that part.
My Quote: Reality TV makes you doubt the truth of your own fantisies
Roderick
You mean like pulling a VW ICE from under the hood of a postal van? Just
kidding.
David C. Wilker Jr.
USAF (RET)
You ever seen reality TV, Well take it from me it ain't reality.
--- End Message ---
--- Begin Message ---
And an insightful thought it was too. I agree. Much of what we use IS used
to transport the vehicle, the fuel itself, etc. Of course there are reasons
for this: Safety, load carrying, staying dry in the rain, etc. I live in a
small town here in CA, and have to drive 15 miles one way to get to work,
school, theaters, etc. Since I wouldn't be able to recharge during my visit,
a good 30+ (Allowing for error) miles range is needed. Also, this trip is at
highway speeds of 55 MPH. If I lived in the city, an electric would have far
less need for speed or range. But I am not giving up. I have a Corsica in
the backyard that would be a good glider to start with. Maybe I could find a
used motor, buy some Lead acid batteries and build a controller and
contactors. I get excited thinking about it, and hope I can pull it off.
Alternatives would be Fuel cells, solar panels, Bio diesel and a used diesel
powered car or truck or possibly even human power. But like I said, I am
just starting out. I have the desire, but little experience or knowledge.
David C. Wilker Jr.
USAF (RET)
----- Original Message -----
From: "Roderick Wilde" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, September 29, 2004 12:27 PM
Subject: Re: Woodburn 2004
Dave, I had an epiphany while riding to work on my electric board scooter
which I do daily. It costs less than one half a kilowatt hour to fill up
which amounts to about three cents a fill up with our electricity rates.
It got me to thinking that most of the energy used to transport people is
not used to transport people. Most of the energy is used to transport the
vehicle. Since it is the person that wants to go someplace and not the
vehicle it made me feel like when I'm driving an ICE vehicle my labor is
going to support some dumb vehicle which could care less how much I spend
on it. Just a different perspective from my twisted mind.
Roderick Wilde
"Suck Amps EV Racing"
www.suckamps.com
----- Original Message -----
From: "Dave" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, September 28, 2004 11:16 PM
Subject: Re: Woodburn 2004
Thanks Rod~
That show was what got me interested in EVs. I can see the writing on the
wall, and it says that fossil fuels for vehicles is going the way of the
dinosaurs. I also am tired of: a) Funding OPEC and the people they
support, b) Watching the cost per mile increase every week while my
income stays the same (VA disability and Military retirement), c) Paying
for SMOG tests and catalytic converters and tune-ups etc just for the
privilege of getting from point "A" to point "B", d) seeing the air and
water of the earth turned into septic wastelands from ICE by-products. I
want to build or buy my own EV of some sort, but I am still a novice
about the science. That is why I lurk here, listening to you guys hash
out the problems, share your experience and crow over the victories. In
my mind, it is the right thing to do. Ok, back to lurking
David C. Wilker Jr.
USAF (RET)
----- Original Message -----
From: "Roderick Wilde" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, September 28, 2004 10:36 PM
Subject: Re: Woodburn 2004
Dave, You are right on! The postal van was actually made at the factory
as an electric but to try to give the audenciece a feel for what it
takes to do a conversion we faked that part.
My Quote: Reality TV makes you doubt the truth of your own fantisies
Roderick
You mean like pulling a VW ICE from under the hood of a postal van? Just
kidding.
David C. Wilker Jr.
USAF (RET)
You ever seen reality TV, Well take it from me it ain't reality.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "jerry dycus" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, September 29, 2004 11:34 AM
Subject: Steve's Fast EV, was , Diablo conversion +, Hurricanes, EV's
> Hi Steve and All,
> --- Steve Clunn <[EMAIL PROTECTED]> wrote:
> Glad to hear your are OK! I was worried as I
> know the power of destruction you faced!
> >
> > ----- Original Message ----- jerry dycus
>
> > Steve Clunn
> >
Umm your 4 hurricanes, maybe more, are about to get trumphed by one of our
local volcanos....
Mt. St Helens is Waking up....
I live for this stuff.
Geez For us Geo Geeks this is heaven. Forget Global warming, think Volcano
triggered winters. THAT we have some pretty good Historic data on...
--- End Message ---
--- Begin Message ---
Emil Naepflein wrote:
On Tue, 28 Sep 2004 13:35:08 -0700, Victor Tikhonov <[EMAIL PROTECTED]>
wrote:
What I meant was you don't need the same equalization complexity
as for a battery (shunt regulators, or like). Simple resistor
network will do.
This kind of passive equalization is only feasable if you don't have
high current chargin like regen on the capacitors. The small current
flowing through the bybass resistors cannot provide equalization if you
charge with 1000 amps. As I have seen most providers of high capacity
ultracapacitors recommend active equalisation, and the circuit is
exaclty like the one you use for the TS lithiums - a voltage clamper.
Emil
You must try it first and comment later.
Resistors work just fine (only a a bit wasteful) because
equalization happens over many stand by hours, not
during driving.
During drive and heavy regens the voltages are not equal
but it is not relevant - faster discharging caps also
charge faster coming to the same voltage anyway.
Only slow equalization needed not to eventually
exceed max per cap voltage on slow charge.
No clamper can bypass 1000A or even 100A current.
And, again, why bother? You don't equalize good
batteries while driving, do you? (boosting a crippled
weak one one is different issue).
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
So, could you use a 1000A 60VDC contactor with a 120V EV system,
assuming < 500A battery current?
Lee Hart wrote:
Eric Poulsen wrote:
Seem most contactors are rated below the actual voltage they're used at
(Albright SW200 is 96VDC). Can anyone clear the air and explain just
how relevant the voltage rating is?
You're right; the actual voltage rating of any switching contact is a
very complicated function of the voltage, current, frequency, waveform,
temperature, atmosphere, etc. etc. Most of the time, manufacturers just
put one "safe" number on their parts. They have a high confidence that
this voltage will be OK in almost any circumstances.
If you know the factors that affect the voltage rating, you can use a
contact at a higher voltage by making sure the worst-case conditions
can't occur.
The higher the current, the lower the voltage rating. So if possible,
minimize the current. This is hard in an EV, where the contactor may be
called upon break thousands of amps of battery short-circuit current.
Keep it clean and dry. Any kind of contamination will provide 'raw
material' that gets carbonized or ionized to help sustain an arc.
Limit the rate of rise in voltage or current. Being mechanical devices,
contacts take time to move between open and closed. During this time,
full voltage or current is probably applied. The arc is generally
'struck' when full voltage and current are present but the contacts are
barely moved apart. One way to control this is with a 'snubber' network.
For instance, my ComutaVan used a 48v rated contactor with a 72v pack.
It had a 2000uF 100vdc electrolytic capacitor across the contacts as a
snubber. When the contact opened, the capacitor carries the current
during the brief time it took the contact to move to the fully-opened
position. This considerably reduced the arc, and allowed the contactor
to sustain the higher voltage safely.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
Victor, what value resistors are you using?
Victor Tikhonov wrote:
39 Ohm each. 25 Watts of power... 25 Wh in an hour or 600 Wh in a
day (24 hours).
Thanks! So, the capacitor's balancing resistors use 0.6 KWH per day.
That is a high "self-discharge" rate, but acceptable if you can keep the
car plugged in.
It is always plugged unless driven.
Or, arrange things so you disconnect the capacitors when parked, let
them go dead, and recharge them when you start driving.
Disconnected, they loose 1V every 3 min. I left the stack
disconnected yesterday for the test, it was 127V lower than
the LiIon pack. Shorting them resulted in a nice spark!
(I know, of course, I need precharge first, etc...).
Or, use zener diodes or some more elaborate circuit (like Rudman
regulators). My guess is that as the capacitors age, you will see larger
variations between them, so more aggressive balancing may become
necessary (same as for batteries; new batteries are easy, old ones get
hard).
Trouble is I have to disconnect the caps because they make
impossible to deploy variable charging current algorithm
required by TS cells - they smooth out all the pulses
in regulation.
I will probably end up maintaining the stack voltage straight
from the mains, simply rectified output and 100 mA capable
secondary will be just fine. (remember, I was asking you about
custom transformers? This is what it is for).
Now, I just have a resistor in series with the caps while
on charge, so they "softly" follow the batteries and do not
interfere that much with charging. A light bulb in parallel
with resistor provides very nice visual feed back.
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "John Wayland" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, September 29, 2004 8:47 AM
Subject: Re: The first EV sports car
> Hello to All,
>
> The title of this post irritates me. The first EV sports car has already
come and gone,
> long before this new entry was even conceived...it was called the EV1. The
EV1 was here 10
> years ahead of the Fetish, and was a sleek two seater electric sports car
within financial
> grasp of many. Road & Track tested it and got 0-60 in 7.6 seconds, and
with NiMH
> batteries, I got a real world 145 miles per charge range when renting one
while traveling
> in California.
>
> John Westlund wrote:
>
> > The TZero is high 11s/ low 12s
>
> John, where are you getting these stats? Take it from me, getting a street
legal electric
> car into the 12's is no small task. Getting a production based, all steel
car with real
> windows, real bumpers, real doors, and a real roof, to run in the 12's let
alone 11's, is
> very hard to do.
>
> Many of us work very hard to design, build, and at sanctioned NHRA 1/4
mile drag
> strips and under NEDRA regulations race our electric drag cars. We come
away with bonafide time
> slips that show everything and support our performance claims. White
Zombie's world record
> 12.991 @ 101.18 mph time slip is posted at the Zombie's page in the EV
Photo Album for all
> to see and inspect.
>
> We've invited AC Propulsion to come to NEDRA drag race EVents, but they've
never attended.
> I have no doubt that the lithium powered tZero could crack the high 12's,
as it ran a 13.2
> second 1/4 mile ET when it was heavier and powered by 28 lead acid
Optimas. High 11s/ low
> 12s? Show me the time slips!
>
> I've seen the tZero videos, most recently, the one with funky earth muffin
music playing
> (no drum track, no bass content, no 'impact'...hardly the kind to support
aggressive,
> tire-shredding 'real' drag racing) where they race the tZero against a
Porsche 911 in the
> rain on some airport tarmac. There were no timing lights, no speed traps,
and it was not
> even close to being NHRA approved. Instead, they have some dude with an
umbrella to act as a
> Christmas tree.
>
> The other 'drag races' AC Propulsion uses in their PR, shows their car
> racing against a Corvette, a Porsche 911, and Ferrari F355...all in the
1/8th mile, not
> the more stringent 1/4 mile, where real drag cars go to see what they can
do. There's a
> reason for this, of course. AC Propulsion knows that in the full 1/4 mile
drag,
> these cars would blow past the tZero, who's performance is capped off with
a self imposed,
> rev limited restricted top speed. Sure, they could change gear ratios to
get the top speed
> up, but doing that would then slow down it's sensational 0-60 time, and,
it would still lose
> to these same cars in the 1/4 mile drag. The tZero would get its fake
doors absolutley blown
> off by all three of these cars.
>
> AC Propulsion's 'drag race' claims (1/8th mile instead of tougher 1/4
mile) are
> reminiscent of Solectria's old tricks, when trying to mask their s-l-o-w
EV's 0-60 times
> they instead bragged about 0-50 in 10 seconds. They only ceased that
nonsense when I
> posted a challenge to their claims and exposed the fact that a car that
does 0-50 in 10
> seconds, takes an agonizing 17 seconds or so to crawl up to 60 mph. I'm
certainly not
> saying tZero isn't quick and fast, but quoting race stats that claim the
tZero 'out-drag
> races' expensive sports cars minus any 60 ft. times, minus any track
registered 1/8th mile
> times and speeds, and most important...minus any 1/4 mile ET and speed, is
a bit
> misleading.
>
> > That TZero is an exceptional machine.
>
> Yes, in some ways it is, but in other ways...hardly. It's absolutely
terrific that AC
> Propulsion has forged ahead with power train and battery pack innovations,
especially the
> recent lap top battery pack and phenomenal distance per charge
achievements. The car has a
> killer 0-60, and it has stunning performance in most areas. However, the
hop-over fake
> doors, the home-made build quality, and toy-like body structure (it's a
kit car) are BIG
> negatives.
>
> I'd like to see a real car with their technology poured into it. A small
> production car made like other cars on the road, a car that passes all
standards other
> cars must pass, a car with functioning doors and all the other expected
features...then
> tout what 'this' car can do. For me, this would be far more impressive
> than what the current 'car' does. Imagine how the general public would
respond when seeing
> a comparison of say a Toyota Corolla XRS, a spunky boy racer 170 hp sedan
with 0-60 in 7.1
> seconds and a 1/4 mile ET of 15.8, to the 230 hp electric Corolla EV with
0-60 in the low
> 5 second range, a 1/4 mile ET in the mid 13's, and a
never-have-to-go-to-the-gas-station
> range of 200-230 miles! Do you have any idea how many eyebrows this would
raise?
>
> See Ya....John Wayland
>
I see John's points here.
The ACP guys have staid off the drag strip.... Where the BS meets the
Road.
While I think that they could put up a fantastic showing... I also think
they don't want us to see the Weakness in thier design. It's really easy to
make somthing fast, but it's harder to make it both fast and quick. The real
question is Why they havn't just taken the Fast company Car to the nearest
strip and bagged some Sub 12 to put into thier Add copy.
With the hype this Car has the the respect that even us NEDRA racers have
for it... They really need to come and play with the Fast street cars that
we have.
And yes I agree that the EV1 was a Electric Vette, come decades early. Under
Stemple it might be on the roads now, in numbers that could make a effect on
the PetroCarbon that we are Spewing in record numbers of tons.
The Tzero is a Kit car compared to the Ev1. To compare them and thier
stats is a insult the the hard hitting guys that made the EV1 happen. We of
course would love to see the Tzero in larger cheaper volumes with a slightly
less mindboggling BMS system.
The Tzero is a Boy racer kit car. Nice but it's not production level. Given
a few dozzen orders...... that of course could change.
What I don't understand is Why Allan and company doesn't show up with about
500Kw and wax our NEDRA Butts back into the stone age of Brushed motors. He
could and he should.
Hint Allan old Boy.... make it rear wheel drive, and don't spare the
silicon, Bring Amps....and lots of them...per phase, of course.
--- End Message ---
--- Begin Message ---
Evan Tuer wrote:
A capacitor will not fail unless is defective to begin with,
and will not need replacement. For the info, BMW uses steering
pump run entirely off of ultracaps, although of course they realise
there is cheap SLA solution.
I didn't know that! I bet it consists of more than just an ultracap
hooked across the motor terminals though?
I don't know any details on that.
Anyway. I think the real question is - why on earth does a *mini*
need power steering in the first place?! :)
Good queastion for Don; I don't own a mini.
Don? Is it possible to manage with manual rack?
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
On Wed, 29 Sep 2004 13:07:42 -0700, Victor Tikhonov <[EMAIL PROTECTED]>
wrote:
>secondary will be just fine. (remember, I was asking you about
>custom transformers? This is what it is for).
THE best place to get custom transformers designed and built is Peter W.
Dahl and associates. I've used him for decades for custom transformers
and large DC power supplies.
http://www.pwdahl.com/
John
---
John De Armond
[EMAIL PROTECTED]
http://bellsouthpwp.net/j/o/johngd/
Cleveland, Occupied TN
--- End Message ---
--- Begin Message ---
Emil, thanks for posting these excellent links!
Emil Naepflein wrote:
On page 15 of
http://www.epcos.com/web/publikationen/pdf/epc690037600.pdf you find a a
schematic for active cell balancing. It is pretty equal to Victors
voltage clamper.
In
http://www.nesscap.com/prod/Articles/JPS_Vol114_2003_pp366-373_NESSCAP.PDF
you find more information about Ultracaps in vehicle applications.
So the effort for balancing UltraCaps is nearly twice as high as with
lithium cells. This drives the costs considerably up.
Emil
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
John Wayland wrote:
> The title of this post irritates me. The first EV sports car has
> already come and gone, long before this new entry was even
> conceived... it was called the EV1.
Right on, John! Not only that, but depending on what we use as the
definition of "EV sports car", there have been dozens of other
contenders over the past 100+years.
--
"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 ---
Evan Tuer wrote:
>
> On Wed, 29 Sep 2004 18:05:13 +0200, Emil Naepflein
> <[EMAIL PROTECTED]> wrote:
>
> > In
> > http://www.nesscap.com/prod/Articles/JPS_Vol114_2003_pp366-373_NESSCAP.PDF
> > you find more information about Ultracaps in vehicle applications.
> >
> > So the effort for balancing UltraCaps is nearly twice as high as with
> > lithium cells. This drives the costs considerably up.
>
> That's interesting. I'm not sure I agree that the effort for
> balancing is twice as high, I use pretty much the same approach as
> this for Li-Ion.
> But, I hate to think what would happen if a couple of the caps went
> short-circuit. Would the rest follow, christmas-tree bulb style? Or
> hand-grenade style? :?
As has been mentioned, no one yet knows how how ultracapacitors will
fail. We know that conventional electrolytics explode, but they don't
burn; they use aluminum plates in a water-based electrolyte. Some of the
ultracapacitors use carbon-based plates in a hydrocarbon electrolyte;
they very well might burn, and have some failure modes like lithium
batteries.
--
"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 ---
Hi everyone,
Some of you may remember a while back I was tossing around
the idea of pulling the electric stuff out of my electric Mini
"Mellow Yellow" and putting it into an X1/9.
Well, the X1/9 is now sitting on my driveway, and it's
worse than I thought. The floorpan is not in good condition,
and needs welding. Plus while I've been poking about in it,
I've found one front fender is fibreglass ( very nicely
fitted, but still only fibreglass ), there's lots of
rust starting in annoying places ( which will ruin the
paint job in a few years ), and I don't fancy doing all
the work to fix it up, constantly.
So it's going back up on Ebay...
... caveat emptor, and all that. :-(
Anyway, on to the point of the story. The Supra seems
to be eating front tyres, and my local tyre/suspension
shop says there's a problem somewhere in the steering
rack and/or balljoints. Ouch. So it's booked in on
Friday, but I absolutely have to get into work on Friday
( big deadline looms... )
So I've been zipping around the lake again, testing out
Mellow Yellow's range, whilst franticly swerving around
all the holes in the road that our local water company
have been digging. They've put 1/2 inch thick steel
slabs over the holes, but they're not pleasant to
drive over in a lead-sled Mini pickup!
Darn it. It seems I have another "stinker" in my pack.
Just 20 amps-hours capacity, according to the E-meter.
Bummer. I noticed this last weekend, and gave the offending
buddy pair a boost using a 15v 30amp PSU, but it obviously
didn't help much. I do have a brand-new Exide Orbital
( Maxxima 900 deep cycle ) sitting on my workbench, for
testing, so I could rig this up with jumper cables to
prop up the weak pair. I'll test this later tonight,
after recharging the pack.
Anyway, the Thundersky UK bulk-buy deadline is approaching,
and I have to make a choice:
Do I :
1. Spend all my money, and get a 120v 100Ah pack
of lithiums, connected in parallel with the best 10
of my AGMs, as has been discussed recently? This would
chop around 1/3 off my pack weight, and give me maybe
80 or 90 Ah of useable capacity. I'd have to scrape together
enough to buy the PFC30 that I've been talking to Rich Rudman
about, to feed the lithiums & AGMs.
2. Buy 20 Exide Orbitals, to have a nice brand new PbA pack.
Also on the cards would be the PFC30, and either a proper
gearbox to help out my motor, or an ADC 9 incher so I can
have more fun!
Option 1 is attractive, but risky ( ThunderSky's seem good so far,
but we don't have much long-term data on them ). I would have more
than enough capacity to get to work, and come back. I have most of
the hardware needed to do a BMS for the lithiums, including some limited
cell balancing ( probably using the pile of 5V 12amp DC:DCs I've got )
Option 2 will work, and work darned well. But the pack will be
"on it's way out" after 500 cycles, and I'll only have just enough
energy to get to work ( my present pack was 100 Ah, probably about
40-odd Ah useable capacity at my discharge rates [ 1C ] before the
present "stinker" appeared ). Plus the poor old Mini is creaking
a bit under the weight of 100Ah of lead, I shudder to think what
would happen if I hit anything ( actually, I know what would
happen, I'd be dead... =:-o )
Decisions, decisions....
Richard Bebbington
electric Mini pickup
--- End Message ---
--- Begin Message ---
I am looking for a 400V, 300A circuit breaker for the pack for my AC
system.
As well, I am looking for a fuse and switch to handle 40A 400v switch for
testing purposes.
I have looked at the EV supply stores, but they are limited to lower
voltages.
Any suggestions on where I look to find such parts?
thanks
Don
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
As has been mentioned, no one yet knows how how ultracapacitors will
fail. We know that conventional electrolytics explode, but they don't
burn; they use aluminum plates in a water-based electrolyte. Some of the
ultracapacitors use carbon-based plates in a hydrocarbon electrolyte;
they very well might burn, and have some failure modes like lithium
batteries.
--
"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
We (Jukka and I) already disassembled and burned a
TS LiIon cell for a test, so we know what parts of it are
combustible and how they sustain fire. Once we have a sample of
a cap, we'll do similar test.
--
Victor
'91 ACRX - something different
--- End Message ---
