EV Digest 3351
Topics covered in this issue include:
1) Re: Sparrow reborn
by Victor Tikhonov <[EMAIL PROTECTED]>
2) Re: AC/DC hybrid drive combo?
by Victor Tikhonov <[EMAIL PROTECTED]>
3) Bit more range...
by Christopher Zach <[EMAIL PROTECTED]>
4) AllTrax Controller Experienc
by "damon henry" <[EMAIL PROTECTED]>
5) Re: Transmission efficiency (Re: The Wheel)
by Victor Tikhonov <[EMAIL PROTECTED]>
6) Re: Sparrow rear suspension was reborn, Comments
by jerry dycus <[EMAIL PROTECTED]>
7) Re: Bit more range...
by Alex Karahalios <[EMAIL PROTECTED]>
8) Re: Transmission efficiency (Re: The Wheel)
by Alex Karahalios <[EMAIL PROTECTED]>
9) Re: Bit more range...
by Michael Hoskinson <[EMAIL PROTECTED]>
10) RE: Transmission efficiency (Re: The Wheel)
by "bholmber" <[EMAIL PROTECTED]>
11) Re: Transmission efficiency (Re: The Wheel)
by "John Bryan" <[EMAIL PROTECTED]>
12) Re: Transmission efficiency (Re: The Wheel)
by Jeff Dubrule <[EMAIL PROTECTED]>
13) Re: ASCII Schematic of hi-lo controller idea
by [EMAIL PROTECTED]
14) Re: Sparrow reborn, in Phoenix???
by Michael Hoskinson <[EMAIL PROTECTED]>
15) Re: Bit more range...
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
16) RE: ASCII Schematic of hi-lo controller idea
by "Reinhard, Rick" <[EMAIL PROTECTED]>
17) Re: Bit more range...
by Chris Zach <[EMAIL PROTECTED]>
18) Re: anyone EVER fried a zilla?
by Rod Hower <[EMAIL PROTECTED]>
19) Re: Bit more range...
by Chris Zach <[EMAIL PROTECTED]>
20) Re: AllTrax Controllers
by [EMAIL PROTECTED]
21) Re: anyone EVER fried a zilla?
by Otmar <[EMAIL PROTECTED]>
22) Re: Bit more range...
by [EMAIL PROTECTED]
23) Re: Bit more range...
by Alex Karahalios <[EMAIL PROTECTED]>
24) Re: Bit more range...
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
25) Re: AC/DC hybrid drive combo?
by Peter VanDerWal <[EMAIL PROTECTED]>
26) Re: Why not Truck Reduction Gears?
by Peter VanDerWal <[EMAIL PROTECTED]>
27) Massive cycle life improvement for Liion?
by Ken Trough <[EMAIL PROTECTED]>
28) Re: AllTrax Controller Experienc
by Peter VanDerWal <[EMAIL PROTECTED]>
29) Re: Transmission efficiency (Re: The Wheel)
by Peter VanDerWal <[EMAIL PROTECTED]>
30) Re: Bit more range...
by Chris Zach <[EMAIL PROTECTED]>
31) Power of DC T-shirt
by Rod Hower <[EMAIL PROTECTED]>
32) Re: Transmission efficiency (Re: The Wheel)
by Seth <[EMAIL PROTECTED]>
--- Begin Message ---
Rich Rudman wrote:
>
> Victor Tikhonov wrote:
...
> > Any info on this Rich? Corbin may be ripped off shopping in wrong
> > place or for the wrong thing. (That is, unless $24k include charging/
> > BMS/all integrated hardware and, may be the batteries
> >
> > --
> > Victor
> > '91 ACRX - something different
>
> Yea Victor it was a ACP drive.
> We had a good laugh about it.
Yes, funny and sad. No matter how hard I think, I cannot
come up with the worse decision than use ACP drive in a Sparrow.
Did they plan to outrun Ferrari in it (for PR) too, or what??
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
>
> Victor Tikhonov wrote:
> >
> > Joe Smalley wrote:
> > >
> > > Rich called me to respond to this.
> > >
> > > Comments inserted...
> >
> >
> > Good, we agree on everything. So I dare to think I know how an
> > induction motor works :-)
> >
> > --
> > Victor
> > '91 ACRX - something different
>
> I still don't think you understand that the 6Khz PWM Freq is almost Not
> a item in this argument.
> That's all I said. Well ment to anyways.
All clear Rich. Trust me I understand a bit more than write in
my posts. Still lots of room to learn though, thanks for
your, Joe's and Lee's inputs.
-
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Given that the DC Wicked Watts is coming up soon now, it's time to think
about getting my Prizm there.
Yes, I could just rent a truck, but that wouldn't be fun. Last year I
was able to drive it there with a brief battery stop in Frederick, and I
might be able to do that again this year (44 miles, edge of range on my
pack)
However another option would be to install more batteries in a custom
tray for range. I'm thinking of going with a string of 13ah Genesis
batteries to be placed in parallel with the existing two strings of 26ah
batteries.
The weight increase would be about 300lbs, but the range would be
extended by at least 12 miles. Maybe more since the resulting pack would
be drained at a lower current.
Can one have three strings in parallel of batteries of different
capacities (2 26ah and one 13ah)? Or would odd things happen once I
passed the 13ah mark? I know the car can handle 300+ lbs of payload
since I drive the wife and kids around in it. Would it be bad to have
this in the trunk?
With an extra 13 miles of range I could probably make it back without a
stop, or make it there with power to spare...
Chris
--- End Message ---
--- Begin Message ---
I am about to take the plunge and buy a new Alltrax controller. I have been
thinking about it for almost a year, but wanted to try a different gear
ratio first just to be sure. I have finally done that test, and am not
satisfied with the results. So before I lay out my hard earned cash I would
like to hear of some first hand experience with these controllers.
I have two main issues and they both have to do with how high I have my bike
geared. The first is very lazy off the line acceleration, and the second is
lack of pull up hills. It seems to me that both these can be fixed with
more current, and I am assuming that an Alltrax will pull alot harder then
my Curtis 1204. I think that to get the off the line performance that I
want I will need to be able to hit the motor with about 200 amps. My Curtis
seems to want to work it's way slowly up to 100 then 150 then 200 amps.
Once it is at about 150 and I am rolling at about 20 mph I like the way it
pulls, it just takes too much time to get there. I'm assuming that the
Alltrax will give me all this current as soon as I tell it to go. Is this
correct?
I know I could change my gearing, but that cuts into my top end too much. I
want to be quick, fast and strong and all on only 48 volts. The only way I
can see to get all this is with a very stout controller.
thanks
damon
_________________________________________________________________
Choose now from 4 levels of MSN Hotmail Extra Storage - no more account
overload! http://click.atdmt.com/AVE/go/onm00200362ave/direct/01/
--- End Message ---
--- Begin Message ---
This analysis is dead wrong, cleverly crafted for PR.
They take 95% efficiency at max load, calculate fixed losses
(remaining 5% expressed in watts) and apply that fixed number
to a light loads. Of course you're going to get terrible
efficiency this way. We know gear boxes are about 95% efficient
at any rated load.
But basically what they've done:
With 100 kW input and 5% losses you loose 5 kW. This is
"fixed" losses you can do nothing about.
Now, if you only need 5 kW to move at steady speed,
you have to provide 10 kW since other 5 will be lost
in the gear box. Viola, your box is just 50% efficient.
Moreover, if you only need to crawl 5 mph and need 500W
to do it, suddenly your transmission becomes 10% efficient.
Poor investors...
Victor
>
> > -----Original Message-----
> > From: Michael Hills [mailto:[EMAIL PROTECTED]
> > Sent: Wednesday, February 11, 2004 1:42 PM
> > To: [EMAIL PROTECTED]
> > Subject: Transmission efficiency (Re: The Wheel)
> >
> > I guess I wasn't too surprised that no one commented on the
> > post below since I think we've seen this (and others like it)
> > before, and wheel motors seem to get dismissed pretty quickly
> > here because of the unsprung weight issues and the fact that
> > this list is mostly focused on things that people on this
> > list can actually buy and use.
> >
> > Anyway, while looking at this site, I was appalled by the
> > fact that they can't even do an efficiency calculation
> > correctly. Then I realized that they were using a comma
> > instead of a decimal point. :) Some of the assumptions they
> > make still look a little iffy, and it's clear they are trying
> > to push their solution, but one of the main points that they
> > are trying to get across got me thinking.
> >
> > They claim that a standard gear train (transmission and
> > differential) consumes about half of the energy produced by
> > an ICE, or by the electric motor in an electric vehicle with
> > a standard drive train. Of course my immediate reaction was
> > "no way" since I "know" they are more than 90% efficient.
> > But the rated efficiency for the transmission is at some
> > torque and RPM. Most of the time the car is cruising at a
> > reduced load. What is the efficiency at that load? One iffy
> > assumption they made was that the power consumed by the
> > transmission is proportional to RPM and does not depend _at
> > all_ on the amount of torque being transferred. That's how
> > they calculate a 50% power consumption (see "Example - a
> > conventionally geared electric bus?" on the web page listed
> > in the original email). It does make sense though that the
> > power transmission efficiency would decrease at loads less
> > than rated torque.
> >
> > Not long ago, someone made a comment saying that a fixed
> > ratio transmission was definitely less efficient.
> > Unfortunately I couldn't find the post in the archives. If I
> > remember correctly (I could be imagining things here), it was
> > Otmar and he said that since he has been leaving CAPOPE in
> > 3rd gear, he's been getting much worse overall efficiency.
> > This shows that the motors are less efficient with a fixed
> > ratio, but to say that the car would be less efficient
> > requires the assumption that removing the transmission and
> > setting the ratio in the differential to be equivalent to 3rd
> > gear wouldn't provide a significant efficiency boost. It
> > seems quite likely that using the transmission during
> > acceleration, when it's being used at close to rated capacity
> > and therefore 90+% efficiency, would improve efficiency, but
> > if it's adding a significant amount of drag at cruise speed,
> > a few miles of that could waste any energy saved during acceleration.
> >
> > Also, in the back of my mind I have a vague recollection of
> > hearing that the Dualin' 7 was actually pretty efficient as
> > long as Rich wasn't laying rubber. Is that true?
> >
> > It seems that in the past people have gotten noticeable range
> > improvements by switching lubricants in their transmission.
> > If the transmission is taking less than 10% of the power,
> > changing the oil would have to make a large difference in the
> > transmission to make a noticeable difference in overall
> > range, and I have a hard time believing that one oil could be
> > _that_ much better than another.
> >
> > Thoughts?
> >
> > Of course none of the examples I've given are substantial
> > (based on remembered second hand info and speculation). Any
> > idea where one could find actual data on the efficiency of
> > typical automotive drive trains at various loads and RPMs?
> >
> > -Michael Hills
> >
> >
> > >Date: Tue, 10 Feb 2004 07:21:44 -0800 (PST)
> > >From: Rod Hower <[EMAIL PROTECTED]>
> > >Subject: The Wheel
> > >
> > >http://www.e-traction.com/TheWheel.htm
> > >
> > >120kW wheel for busses/forklifts.
> > >
> > >Perhaps 2 on the back of CE would be nice.
> >
> > _________________________________________________________________
> > Plan your next US getaway to one of the super destinations here.
> > http://special.msn.com/local/hotdestinations.armx
> >
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Hi Alan and All,
Great group of pics!!
If the rest of the Sparrow is designed the
same way, no wonder they went bankrupt.
The people redoing the Sparrow would be
smart to redesign it after stock is gone or use stock
for replacement parts for existing Sparrows and start
with a better design.
It could be done in 1/2 the parts- labor,
costs.
Thanks,
jerry dycus
--- Alan Batie <[EMAIL PROTECTED]> wrote:
> On Tue, Feb 10, 2004 at 06:11:40PM -0800, jerry
> dycus wrote:
> > Any pics of the Sparrow rear swing arm,
> > drive, around? Anyone know what parts, bearings,
> > brake, they used by the wheel?
>
> I don't know about parts, but here's pics from when
> I had to take mine
> apart to replace the motor:
>
> http://alan.batie.org/photos/nikon/000902-sparrow/
>
> --
> Alan Batie ______
> alan.batie.org Me
> alan at batie.org \ / www.qrd.org
> The Triangle
> PGPFP DE 3C 29 17 C0 49 7A \ / www.pgpi.com
> The Weird Numbers
> 27 40 A5 3C 37 4A DA 52 B9 \/
> spamassassin.taint.org NO SPAM!
>
> To announce that there must be no criticism of the
> President, or that we
> are to stand by the President, right or wrong, is
> not only unpatriotic
> and servile, but is morally treasonable to the
> American public.
> -Theodore Roosevelt, 26th US President (1858-1919)
>
__________________________________
Do you Yahoo!?
Yahoo! Finance: Get your refund fast by filing online.
http://taxes.yahoo.com/filing.html
--- End Message ---
--- Begin Message ---
I was just thinking the same thing today (even the 13Ah part). I would
think that your 13Ah batteries would give out before the 26Ah batteries
would. Maybe as the 13Ah batteries' voltage starts to sag, the 26Ah
batteries would keep them charged.
But I believe your scenario is just like when you have unbalanced
batteries in your pack: eventually you wind up destroying those
batteries. You will also have a problem charging them unless you just
stick to CV charging since during the CC phase the 13Ah batteries will
reach peak voltage first.
Alex Karahalios
On Feb 11, 2004, at 2:51 PM, Christopher Zach wrote:
Can one have three strings in parallel of batteries of different
capacities (2 26ah and one 13ah)? Or would odd things happen once I
passed the 13ah mark? I know the car can handle 300+ lbs of payload
since I drive the wife and kids around in it. Would it be bad to have
this in the trunk?
--- End Message ---
--- Begin Message ---
Speaking of transmission lubricants, has anyone actually replaced their
lubricant and noticed any improvement/ And if so, what lubricant did
you use?
Alex Karahalios
On Feb 11, 2004, at 12:42 PM, Michael Hills wrote:
It seems that in the past people have gotten noticeable range
improvements by switching lubricants in their transmission. If the
transmission is taking less than 10% of the power, changing the oil
would have to make a large difference in the transmission to make a
noticeable difference in overall range, and I have a hard time
believing that one oil could be _that_ much better than another.
--- End Message ---
--- Begin Message ---
I haven't got the data to prove it yet, but I believe that it would be
the constant voltage phase you'd have to shorten. During the CC
phase, the voltage in the 2 paralleled strings would be the same. The
13 Ah string would see the voltage go up slower with the 26 Ah string
sopping up the amps, compared to the rate of change if you were
charging the 13 Ah string by itself. So when you reach the acceptance
voltage, the 13 Ah pack would be more full. It would require a
shorter CV phase, and if you left the charger on until the other pack
was fully charged, you'd be overcharging the smaller capacity pack.
So the way to do it without harming the smaller pack would be to cut
it out of the circuit earlier in the CV phase.
This makes sense to me, though I may be missing something... I plan to
do some tests with a small helper pack of (freebee) AGM's paralleled
to the big floodies, measuring current in both legs of the paralleled
strings. Right now, hovever, my "D" is down while I sort out a
vibration problem in the drive train. Seems to be the adapter - I've
sent it back to Randy to get his machinist to check it out. A
boot-to-the-head for the machinist if it turns out (if you'll excuse
the expression) to be faulty. Boot-to-the-head for me if it was
somehow my fault.
Mike Hoskinson
Edmonton
P.S. sorry about repeating the advice about trimming the Sparrow motor
shaft - I didn't see the other post until after I sent mine.
m
Alex Karahalios wrote:
I was just thinking the same thing today (even the 13Ah part). I would
think that your 13Ah batteries would give out before the 26Ah batteries
would. Maybe as the 13Ah batteries' voltage starts to sag, the 26Ah
batteries would keep them charged.
But I believe your scenario is just like when you have unbalanced
batteries in your pack: eventually you wind up destroying those
batteries. You will also have a problem charging them unless you just
stick to CV charging since during the CC phase the 13Ah batteries will
reach peak voltage first.
--- End Message ---
--- Begin Message ---
As long as your transmission seals are good, you could swap Castrol 20-50W
for the gear oil in the transmission in a RX-7 and expect to get 1-2 more
miles to the gallon. On average I would get around 25-27mpg. So the
improvement wasn't huge, but it was noticeable.
Brett
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Alex Karahalios
Sent: Wednesday, February 11, 2004 2:22 PM
To: [EMAIL PROTECTED]
Subject: Re: Transmission efficiency (Re: The Wheel)
Speaking of transmission lubricants, has anyone actually replaced their
lubricant and noticed any improvement/ And if so, what lubricant did
you use?
Alex Karahalios
On Feb 11, 2004, at 12:42 PM, Michael Hills wrote:
> It seems that in the past people have gotten noticeable range
> improvements by switching lubricants in their transmission. If the
> transmission is taking less than 10% of the power, changing the oil
> would have to make a large difference in the transmission to make a
> noticeable difference in overall range, and I have a hard time
> believing that one oil could be _that_ much better than another.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Alex Karahalios"
> Speaking of transmission lubricants, has anyone actually replaced their
> lubricant and noticed any improvement/ And if so, what lubricant did
> you use?
When I had the stock gear oil in my EV Ghia, I didn't need to
use the brakes to stop in the winter! In fact I had to stay on the power
a little bit to make it all the way to the light. On this list I found out
about Redline MTL and switched to it. Now the car coasts great
both winter and summer. It's a bit expensive, but in my opinion well
worth it. Do some research on this product on the Net, it is a
fantastic lubricant for manual transmissions. MTL stands for
Manual Transmission Lubricant. It costs around $7.95 a quart,
and is well worth it. Your local NAPA either carries it or can
order it for you.
...John
--- End Message ---
--- Begin Message ---
On Wed, Feb 11, 2004 at 03:22:04PM -0700, Alex Karahalios wrote:
> Speaking of transmission lubricants, has anyone actually replaced their
> lubricant and noticed any improvement/ And if so, what lubricant did
> you use?
Well, not in an EV, but I have replaced the transmission lube in my
ICE car.
The Subaru transmission, as it comes, has kinda thick dino oil in
there, which, in NH winter temperatures, feels like you're dragging a
spoon through peanut-butter. I had also put in a short-shift kit,
which would've made it darned-near impossible to shift.
I used 'Red Line MT-90' oil, which is a synthetic oil designed for
racing applications, and it made a world of difference. Shifts were
very smooth, and I could feel all the 'notches' of the transmission
nicely, so I wouldn't misshift.
Transmission oil, for an ICE, needs to be both slippery (for long
bearing/gear life), and "sticky" so the synchros work without
grinding. Friction modifiers are used to get this balance right.
In an EV, which you probably won't shift all that often, I'd say
getting a gear oil such as is used in a rear-differential would
probably be OK. Red Line 75W90 oil might be a good choice.
-jeff
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* LP8.2: HTML/Attachments detected, removed from message *
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Phoenix Environmental Motors bought an old Citroen 2CV last year from
the dealer here in Edmonton where I bought my D. It was parked right
next to the wrecked D that he gave me for spare parts.
I was disappointed at the time because I kinda had my eye on the 2CV
as a "next" conversion project. This was at a period in my D project
when my wife wouldn't let me consider doing another one. That period,
sadly, is likely to last at least until I finish the first one. Come
to think of it, she won't EVen let me try a different battery pack.
"You've got enough batteries!", she said. Imagine! That's like saying
You've had enough beer".
Mike Hoskinson
Edmonton
[EMAIL PROTECTED] wrote:
Guys,
The name of the company is "Phoenix Environmental Motors". The Phonenix
reference is for the bird, which rises anew from the ashes. The actual
location is up in Clear Lake, California.
-Ed Thorpe
--- End Message ---
--- Begin Message ---
Why not pull a battery trailer? It'd be much easier to make, and you
could add a lot more capacity. Might be cheaper too, especially if you
filled it up with golf car or marine batteries.
You could even fit it with a controller and inductor to limit the rate at
which you discharged 'em, letting the Hawkers in the car handle higher
current acceleration. But then you're getting into a little more work.
--- End Message ---
--- Begin Message ---
This what I get from Ray
JR can you change your setting to include plain text?
So those of us behind the Microsoft curtain can see too!
Rick R
-----Original Message-----
From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]
Sent: Wednesday, February 11, 2004 3:11 PM
To: [EMAIL PROTECTED]
Subject: Re: ASCII Schematic of hi-lo controller idea
* LP8.2: HTML/Attachments detected, removed from message *
--- End Message ---
--- Begin Message ---
Thought about that, but I don't think the added weight for things like
the trailer, the added rolling resistance, and the increased drag due to
wind resistance would help. Might not be as much range as I want.
The true golden trick would be to put in a pack of *lithium ion*
batteries and tie them into the main pack. Unfortunately I would need a
300 volt pack, which is a lot of TS batteries :-)
Is it just me, or do NiMH batteries have not much more energy density
than lead? I did some quick calculations, and found it would take about
200lbs of Nickel Metal batteries to equal the 300lbs of lead. Less if I
have to build a super-controlller to charge the NiMH pack.
Chris
David Roden (Akron OH USA) wrote:
Why not pull a battery trailer? It'd be much easier to make, and you
could add a lot more capacity. Might be cheaper too, especially if you
filled it up with golf car or marine batteries.
You could even fit it with a controller and inductor to limit the rate at
which you discharged 'em, letting the Hawkers in the car handle higher
current acceleration. But then you're getting into a little more work.
--- End Message ---
--- Begin Message ---
The Z2K gate drives go from zero to 70
amps 30,000 times a second.
Otmar,
Just curious why you went with 30khz switching
when 20khz is not audible. This introduces additional
switching losses for the IGBT's.
You're a pretty smart guy, so I'm sure there is a
reason. I am interested as a control designer why
you chose this frequency.
Thanks,
Rod
--- End Message ---
--- Begin Message ---
I was just thinking the same thing today (even the 13Ah part). I would
think that your 13Ah batteries would give out before the 26Ah batteries
would. Maybe as the 13Ah batteries' voltage starts to sag, the 26Ah
batteries would keep them charged.
Well, maybe. I mean if you take one of those 26ah battery strings and
physically saw the batteries in halk for one string and tie them all
together you still have the same pack :-)
I guess the question boils down to do batteries behave like inverted
resistors in a circuit. IE: The 13ah batteries would have only half the
internal resistance of a 26ah battery, and some fraction of the internal
resistance of a 52ah paired pack. (1/Rt=1/R1+1/R2+1/R3 or something like
that) Thus when you draw power from the pack, 5/6th comes from the 52ah
side and 1/6 comes from the 13ah side.
There's a formula for this somewhere perhaps. Any thoughts?
Chris
--- End Message ---
--- Begin Message ---
Their webpage doesn't list the SepEx controller mentioned on EVDL, but there
aren't too many shunt motors mentioned here either. We do talk about Etek
motors, and I'd like to see what AllTrax can do with regen - might not feed
much amp-hrs into the pack in small EVs, but certainly spares the brakes!
--- End Message ---
--- Begin Message ---
At 3:53 PM -0800 2/11/04, Rod Hower wrote:
The Z2K gate drives go from zero to 70
amps 30,000 times a second.
Otmar,
Just curious why you went with 30khz switching
when 20khz is not audible. This introduces additional
switching losses for the IGBT's.
You're a pretty smart guy, so I'm sure there is a
reason. I am interested as a control designer why
you chose this frequency.
Thanks,
Rod
Actually I didn't. I switch at 15.7 khz but the gate drive pulses
come twice per cycle. Once for turn on and once for turn off. I guess
to be more accurate I should have said 0 to 70 and then 0 to -70 15K
times a second...
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
<<Can one have three strings in parallel of batteries of different
capacities (2 26ah and one 13ah)? Or would odd things happen once I
passed the 13ah mark? I know the car can handle 300+ lbs of payload
since I drive the wife and kids around in it. Would it be bad to have
this in the trunk?>>
I think we discussed this on the EVDL before: as long as the paralleled packs
are of the same voltage and battery type, no matter what the capacity, they act
as one whole pack (i.e.- two packs of 26Ah and one of 13Ah is about the same as
one pack of 65Ah).
--- End Message ---
--- Begin Message ---
You're right. I was picturing these wired in series - not parallel.
Alex Karahalios
On Feb 11, 2004, at 5:06 PM, [EMAIL PROTECTED] wrote:
I think we discussed this on the EVDL before: as long as the
paralleled packs
are of the same voltage and battery type, no matter what the capacity,
they act
as one whole pack (i.e.- two packs of 26Ah and one of 13Ah is about
the same as
one pack of 65Ah).
--- End Message ---
--- Begin Message ---
On 11 Feb 2004 at 18:42, Chris Zach wrote:
> Thought about that, but I don't think the added weight for things like the
> trailer, the added rolling resistance, and the increased drag due to wind
> resistance would help. Might not be as much range as I want.
I figure it worked for Team New England. They won the Tour de Sol a few
years back with a trailer full of batteries. Olaf Bleck's website says, "We set
a Lead-Acid range record of 156 miles and the actual range of the car is
about 180 miles." This is a Solectria Force. Pic here:
http://www.ai.mit.edu/people/bleck/forsale/tds99-1.jpg
I gotta try this one of these days.
--- End Message ---
--- Begin Message ---
> Now, if the big AC and DC motors are coupled to each other and uncoupled
> from the wheels, they could perhaps be used as a motor-generator for
> battery charging. This could provide a high-power charger for very
> little additional cost and weight (since the big expensive parts are
> already in the car).
Wouldn't it make more sense to use the incoming AC to drive the series
wound DC motor and use the AC motor with it's nice integrated regen to
charge the batteries?
Granted you will have some problems with eddy currents in the DC motor
since the stator doesn't have laminations, but at the reduced power
levels this shouldn't be much of a problem.
This way you don't have to worry about trying to get regen from a series
wound motor and the accompanying problems with brush advance etc.
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Well, assuming 15" wheels and an ADC motor, you are going to need gear
ratios of roughly 8:1 and 5:1. Which "standard" truck parts provide
these ratios?
Just curious, my knowledge deals mostly with cars and light trucks.
On Wed, 2004-02-11 at 07:48, Aaron Birenboim wrote:
> I expect that people here have tried about everything,
> so I'm assuming that truck reduction gears and/or overdrive
> differentials have been dismissed for some reason.
>
> I'm just curious about why?
> If all we need is some reduction gearing for an EV, why
> not use standard truck parts? Are they too heavy and innefficient?
>
> Why not use reduction gear sets or overdrives as a simple
> 2-speed transmission, since most EVs (even DC) only really need
> 2 gears?
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Apparently this tech was profiled in December's Scientific American
magazine as one of the top 67 most important discoveries of the year.
Khalil Amine, a group leader in battery tech for Argonne National
Laboratory in Argonne, IL, was singled out for his team's development of
a lithium manganese process. These new liion batteries use a manganese
crystal that is expected to last the life of a car, meaning no expensive
battery replacements for BEV owners along with the longer range and
lighter weight that Liion delivers.
I know that Compact Power in Boulder, CO has a Lithium Manganese cell
that offers high charge and discharge rate characteristics and
significantly reduced fire hazard. Compact power was saying they were
going to limited production in late 2004 (the CEO said this at ETIC in
early 2003), but these cells are being developed by LG Korea, and LG was
saying it would be 6 years to commercialization at EVS-20 in Long Beach.
8^(
So anyway, anyone know about Khalil Amine's team, process,
commercialization plans or schedule? This process is promising enough
that it has automakers sitting up and taking notice.
I'll be doing more research myself, but I thought I'd throw it out there
to see if anyone has unpublished info.
-Ken Trough
http://visforvoltage.com
24 hour AIM - ktrough
24 hour message center - 866-872-8901
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You can have Golf Tech rebuild your curtis controller without the
ramp-up (hi pot?).
Just an option to consider.
> I have two main issues and they both have to do with how high I have my bike
> geared. The first is very lazy off the line acceleration, and the second is
> lack of pull up hills. It seems to me that both these can be fixed with
> more current, and I am assuming that an Alltrax will pull alot harder then
> my Curtis 1204. I think that to get the off the line performance that I
> want I will need to be able to hit the motor with about 200 amps. My Curtis
> seems to want to work it's way slowly up to 100 then 150 then 200 amps.
> Once it is at about 150 and I am rolling at about 20 mph I like the way it
> pulls, it just takes too much time to get there. I'm assuming that the
> Alltrax will give me all this current as soon as I tell it to go. Is this
> correct?
>
> I know I could change my gearing, but that cuts into my top end too much. I
> want to be quick, fast and strong and all on only 48 volts. The only way I
> can see to get all this is with a very stout controller.
>
> thanks
> damon
>
> _________________________________________________________________
> Choose now from 4 levels of MSN Hotmail Extra Storage - no more account
> overload! http://click.atdmt.com/AVE/go/onm00200362ave/direct/01/
--
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
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I switched to some trans lube called "Royal Purple" and saw approx 10%
reduction in AHs for my normal commute. Used it in both the tranny and
diff.
It quieted the trany down too.
On Wed, 2004-02-11 at 15:22, Alex Karahalios wrote:
> Speaking of transmission lubricants, has anyone actually replaced their
> lubricant and noticed any improvement/ And if so, what lubricant did
> you use?
>
> Alex Karahalios
>
> On Feb 11, 2004, at 12:42 PM, Michael Hills wrote:
>
> > It seems that in the past people have gotten noticeable range
> > improvements by switching lubricants in their transmission. If the
> > transmission is taking less than 10% of the power, changing the oil
> > would have to make a large difference in the transmission to make a
> > noticeable difference in overall range, and I have a hard time
> > believing that one oil could be _that_ much better than another.
--
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
--- End Message ---
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Interesting. A pack of 25 Dynasty UPS batteries (75ah) would weigh about
1,400lbs and would boost my theoretical range to 125 miles or so. Maybe
lead is the answer.
So who makes a small trailer that can handle 2,000 lbs?
Chris
David Roden (Akron OH USA) wrote:
On 11 Feb 2004 at 18:42, Chris Zach wrote:
Thought about that, but I don't think the added weight for things like the
trailer, the added rolling resistance, and the increased drag due to wind
resistance would help. Might not be as much range as I want.
I figure it worked for Team New England. They won the Tour de Sol a few
years back with a trailer full of batteries. Olaf Bleck's website says, "We set
a Lead-Acid range record of 156 miles and the actual range of the car is
about 180 miles." This is a Solectria Force. Pic here:
http://www.ai.mit.edu/people/bleck/forsale/tds99-1.jpg
I gotta try this one of these days.
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Thanks to Chip Gribben for getting this T-shirt
sent out in record time.
I also ordered two T-shirts from EVparts, 'Suck amps'
and 'goin postal'
My usual weekend and week night apparrel is EV shirts.
This usually brings up questions about EV's even if
they don't notice I'm driving one. After the T-shirt
question I show them the van and talk about the
Current Eliminator, Zombie, CApopy, postal van or
many of the other kick ass EV's out there.
It really makes people think about EV's.
So, keep up the good work, EV shirts are good
advertisement.
Rod
www.qsl.net/w8rnh
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--- Begin Message ---
A year ago I would have agreed with Victor. And while I don't exactly
agree with the wheel motor guys (not a fair representation of the
losses), I can say that I have measured light load losses that were
lots higher than I thought possible in a transmission. I don't have the
answer for full load numbers. But full load in a transmission doesn't
matter much for efficiency. You already have the controller floored,
after all. Most (nearly all) of the driving is al light/part load. And
at least in what I have *measured* (a longitudinal transmission like
you would find in a pickup, but bigger), the drag is fairly constant
across the RPM range, resulting in a power loss proportional to shaft
speed. I could not measure losses due to torque transmission. So 70%
efficiency might be a real opeation point. Low power, high shaft speed,
(highway cruising)- losses aren't staggering, but a fixed loss against
a low power does show up as poor efficiency in this case.
Then you weigh it against the motor efficiency map and time spent at
operational points to decide what ratio(s) to use based on what the
motor losses versus the multispeed transmission losses are. Assuming of
course you know your drive cycle...
Seth
AKA "the cynic"
"the other Seth"
"I lost on eBay too"
"Lee Hart ASCII art fan club member #47"
On Feb 11, 2004, at 5:04 PM, Victor Tikhonov wrote:
This analysis is dead wrong, cleverly crafted for PR.
They take 95% efficiency at max load, calculate fixed losses
(remaining 5% expressed in watts) and apply that fixed number
to a light loads. Of course you're going to get terrible
efficiency this way. We know gear boxes are about 95% efficient
at any rated load.
But basically what they've done:
With 100 kW input and 5% losses you loose 5 kW. This is
"fixed" losses you can do nothing about.
Now, if you only need 5 kW to move at steady speed,
you have to provide 10 kW since other 5 will be lost
in the gear box. Viola, your box is just 50% efficient.
Moreover, if you only need to crawl 5 mph and need 500W
to do it, suddenly your transmission becomes 10% efficient.
Poor investors...
Victor
-----Original Message-----
From: Michael Hills [mailto:[EMAIL PROTECTED]
Sent: Wednesday, February 11, 2004 1:42 PM
To: [EMAIL PROTECTED]
Subject: Transmission efficiency (Re: The Wheel)
I guess I wasn't too surprised that no one commented on the
post below since I think we've seen this (and others like it)
before, and wheel motors seem to get dismissed pretty quickly
here because of the unsprung weight issues and the fact that
this list is mostly focused on things that people on this
list can actually buy and use.
Anyway, while looking at this site, I was appalled by the
fact that they can't even do an efficiency calculation
correctly. Then I realized that they were using a comma
instead of a decimal point. :) Some of the assumptions they
make still look a little iffy, and it's clear they are trying
to push their solution, but one of the main points that they
are trying to get across got me thinking.
They claim that a standard gear train (transmission and
differential) consumes about half of the energy produced by
an ICE, or by the electric motor in an electric vehicle with
a standard drive train. Of course my immediate reaction was
"no way" since I "know" they are more than 90% efficient.
But the rated efficiency for the transmission is at some
torque and RPM. Most of the time the car is cruising at a
reduced load. What is the efficiency at that load? One iffy
assumption they made was that the power consumed by the
transmission is proportional to RPM and does not depend _at
all_ on the amount of torque being transferred. That's how
they calculate a 50% power consumption (see "Example - a
conventionally geared electric bus?" on the web page listed
in the original email). It does make sense though that the
power transmission efficiency would decrease at loads less
than rated torque.
Not long ago, someone made a comment saying that a fixed
ratio transmission was definitely less efficient.
Unfortunately I couldn't find the post in the archives. If I
remember correctly (I could be imagining things here), it was
Otmar and he said that since he has been leaving CAPOPE in
3rd gear, he's been getting much worse overall efficiency.
This shows that the motors are less efficient with a fixed
ratio, but to say that the car would be less efficient
requires the assumption that removing the transmission and
setting the ratio in the differential to be equivalent to 3rd
gear wouldn't provide a significant efficiency boost. It
seems quite likely that using the transmission during
acceleration, when it's being used at close to rated capacity
and therefore 90+% efficiency, would improve efficiency, but
if it's adding a significant amount of drag at cruise speed,
a few miles of that could waste any energy saved during acceleration.
Also, in the back of my mind I have a vague recollection of
hearing that the Dualin' 7 was actually pretty efficient as
long as Rich wasn't laying rubber. Is that true?
It seems that in the past people have gotten noticeable range
improvements by switching lubricants in their transmission.
If the transmission is taking less than 10% of the power,
changing the oil would have to make a large difference in the
transmission to make a noticeable difference in overall
range, and I have a hard time believing that one oil could be
_that_ much better than another.
Thoughts?
Of course none of the examples I've given are substantial
(based on remembered second hand info and speculation). Any
idea where one could find actual data on the efficiency of
typical automotive drive trains at various loads and RPMs?
-Michael Hills
Date: Tue, 10 Feb 2004 07:21:44 -0800 (PST)
From: Rod Hower <[EMAIL PROTECTED]>
Subject: The Wheel
http://www.e-traction.com/TheWheel.htm
120kW wheel for busses/forklifts.
Perhaps 2 on the back of CE would be nice.
_________________________________________________________________
Plan your next US getaway to one of the super destinations here.
http://special.msn.com/local/hotdestinations.armx
--
Victor
'91 ACRX - something different
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