EV Digest 4169
Topics covered in this issue include:
1) Re: BB-600 Nicad Cells
by Derrick J Brashear <[EMAIL PROTECTED]>
2) Re: 9' ADC aft mounting holes (rather, lack thereof)
by Electro Automotive <[EMAIL PROTECTED]>
3) Re: 9" ADC aft mounting holes (rather, lack thereof)
by "Paul Compton" <[EMAIL PROTECTED]>
4) Re: Las Vegas NEDRA Wicked Watts Head Count
by "Chip Gribben" <[EMAIL PROTECTED]>
5) Re: Tire pressure for lower rolling resistance?
by Ryan Stotts <[EMAIL PROTECTED]>
6) Re: AC Bandsaw motor questions
by Ryan Stotts <[EMAIL PROTECTED]>
7) Re: Jeep EV Update (New Controller!)
by Ryan Stotts <[EMAIL PROTECTED]>
8) RE: Comet CVT/Torque converters in a lightweight ev?
by "Roger Stockton" <[EMAIL PROTECTED]>
9) Re: AC Bandsaw motor questions
by Rush <[EMAIL PROTECTED]>
10) RE: 9' ADC aft mounting holes (rather, lack thereof)
by Dave Cover <[EMAIL PROTECTED]>
11) Re: AC Bandsaw motor questions
by Lee Hart <[EMAIL PROTECTED]>
12) Re: 9" ADC aft mounting holes (rather, lack thereof)
by Lee Hart <[EMAIL PROTECTED]>
13) LA to Vegas
by [EMAIL PROTECTED]
14) RE: 9' ADC aft mounting holes (rather, lack thereof)
by "Will" <[EMAIL PROTECTED]>
15) Re: Comet CVT/Torque converters in a lightweight ev?
by "Tim Humphrey" <[EMAIL PROTECTED]>
16) Re: Jeep EV Update (New Controller!)
by Mark Farver <[EMAIL PROTECTED]>
17) Re: Comet CVT/Torque converters in a lightweight ev?
by Lee Hart <[EMAIL PROTECTED]>
18) RE: PM w/ separate lead for each brush?
by "Myles Twete" <[EMAIL PROTECTED]>
19) RE: Electric boat controls
by "Myles Twete" <[EMAIL PROTECTED]>
20) Re: BB-600 Nicad Cells: SoCal group buy?
by Reverend Gadget <[EMAIL PROTECTED]>
21) Stop deceptive ads by Automakers
by Sherry Boschert <[EMAIL PROTECTED]>
22) RE: Peukerts for LI-Poly (was Re: Additional outside funding)
by "Myles Twete" <[EMAIL PROTECTED]>
23) Re: Jeep EV Update (New Controller!)
by "Christopher Robison" <[EMAIL PROTECTED]>
24) Re: Jeep EV Update (New Controller!)
by Ryan Stotts <[EMAIL PROTECTED]>
25) RE: PM w/ separate lead for each brush?
by "Myles Twete" <[EMAIL PROTECTED]>
26) Re: PM w/ separate lead for each brush?
by Lee Hart <[EMAIL PROTECTED]>
27) Re: Jeep EV Update (New Controller!)
by Victor Tikhonov <[EMAIL PROTECTED]>
28) "The future of electric drag racing is in AC"
by Ryan Stotts <[EMAIL PROTECTED]>
--- Begin Message ---
Huh. My replies bounced too. Damn
Well, hopefully there are 300 cells left that I can get.
--- End Message ---
--- Begin Message ---
Yes, proper alignment of the motor in the car is important. Our 914 mount
takes care of this issue.
Ben, you may have a very early 9" motor. The first ones did NOT have the
two mounting pads. If you have one of these, do NOT attempt to drill
it. The metal isn't thick enough. Or you may have one that escaped the
factory WITH the mounting pads, but not drilled. If this is the case, you
can get away with drilling them. If you have a fax number, I can fax you a
drawing showing exactly where the holes should be. Another possibility
would be to see if there is anyone out there with a trashed 9" motor and a
good end bell they would sell/give you.
You don't use a 3/8" bit to drill a hole for a 3/8" bolt. You need a 5/16"
bit.
The mounting system for the electric motor replicates the factory 914 motor
mount system, supporting the motor at the front and the transmission at the
rear. Any other setup is liable to give you grief.
We do recommend cradle mounts in some models, but we do not recommend
generic one-size-fits-nothing-quite-right versions. The mount should be
designed and fitted to the car in question. We have a tech paper on how to
do this.
Mike Brown
Electro Automotive POB 1113 Felton CA 95018-1113 Telephone 831-429-1989
http://www.electroauto.com [EMAIL PROTECTED]
Electric Car Conversion Kits * Components * Books * Videos * Since 1979
--- End Message ---
--- Begin Message ---
Second try!
I doubt a band clamp would work very well, since my
understanding is that it wouldn't do a very good job preventing rotation,
and there's really nothing else in the engine compartment to which one
could mount the motor.
The torque reaction in a 914 is around the driveshafts, so you really just
need to support the end of the motor vertically. I'm trying to remember how
we did it in No.13. I remember replacing the heavy Porsche front mounting
beam with a welded tube arrangement (part of our continuous efforts to keep
the wight down), but I can't quite remomber how it was atattched to the
motor and I don't think I've got any pictures. I spent enough time lying
underneath that damn car, you'd think I'd remember.
The alignment isn't that critical, we lowered the motor quite a lot, but you
do have to make sure the shift linkage works properly. It's a pretty hidious
pile of junk at the best of times.
Paul Compton
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
When you said sorry I thought, "Oh no, Brian can't make it".
But after reading further, I was relieved. Having Ice Breaker there will be
great.
Chip
http://www.nedra.com
----- Original Message -----
From: "Brian D.Hall" <[EMAIL PROTECTED]>
To: "ev post" <ev@listproc.sjsu.edu>
Sent: Wednesday, March 09, 2005 11:53 AM
Subject: Fw: Las Vegas NEDRA Wicked Watts Head Count
> Sorry Chip , I'm not sure if we are going to make it this year with the
> Bikes, If I do come it would be with ICE Breaker, I'm now raising the
> voltage and want to get a few runs in at the local track before this April
> event happens.
> Brian
--- End Message ---
--- Begin Message ---
Patrick Maston wrote:
> Both the tires I have to choose from have the same maximum weight
> rating: 1047 lbs. , do I want the one that takes 51PSI @ 1047 lbs, or the
> one that
> takes 44PSI @1047 lbs?
I have 44 psi tires on my ICE and with them aired up all the way to
44, they are still bulged out and "look" under inflated. I'd go for
the 51 psi tires since they should offer less rolling resistance.
Think about a mountain bike with the tires aired up to 40 psi or
whatever they take, and a "10 speed" with 1/2" wide tires aired up to
100+ psi. If you've ridden both on the street, the mountain bike is
slow like an old WW2 tank, and the 10-speed flies. Put those 10 speed
tires on the mountain bike frame...
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
> Just out of curiosity, have you checked with the power company to see how
> much it would cost to have three phase power installed?
> Probably more expensive than either option you've mentioned, but it
> doesn't cost anything to ask.
I'm just wondering in my case, for future reference. The power lines
in this neighborhood are all underground. Could I get 3 phase hooked
up using the existing line that runs under the backyard to the meter
on the back of the house?
--- End Message ---
--- Begin Message ---
>Christopher Robison wrote:
> Mark Farver said:
>
> > The DCP DC/DC is basically no longer available. I understand that a
> > dozen or so are still around but that the current owner is hesitant to
> > put them into the retail channel. This leaves the EV industry with no
> > high voltage capable DC/DC products. Someone needs to start thinking
> > about repackaging an Vicor or Meanwell device.
>
> I've complained about it before so I won't add too much here, other than
> my agreement. This is a hole in the market that would guarantee at least
> a temporary monopoly to the party that fills it.
So the situation currently is that their is not a suitable DC/DC for
the 12 volt needs in an EV?
--- End Message ---
--- Begin Message ---
Tim Medeck [mailto:[EMAIL PROTECTED] wrote:
> My Freeway has a comet torque converter. It turns at all RPM,
> but the cones don't start to close until 800 RPM. It works
> okay for forward, but reverse stinks because the cones don't
> close when you reverse the rotation of the converter. It
> backs up, but with a lot of slipping and jumping of the belt.
The problem your Freeway has is that the driven sheave is being turned
backwards; the clutch sheave will close the same when rotated in either
direction (the flyweights travel outward radially the same regardless of
the direction of rotation).
One side of the driven sheave is typically fixed to the shaft while the
other side can rotate against spring tension and move away from the
fixed sheave as it travels along some ramps. This allows the belt to
ride lower in the driven sheave and yields a higher gear (lower
reduction ratio) effect.
The problem is that when you rotate the driven sheave opposite to its
intended direction of rotation, the belt rotates the movable side of the
sheave easily so that it moves away from the fixed half and results in
less pressure on the sides of the belt such that the belt slips.
You could fix this problem with some means of preventing the movable
face of the driven sheave from moving away from the fixed face. A
possiblity is a cable operated idler wheel that could be brought to bear
against the backside of the movable half when in reverse that would
either prevent the movable half from moving away from the fixed face or
would at least greatly increase its resistance to movement.
The 'proper' solution is probably to locate a chaincase from a
snowmachine that was equipped with reverse gear and install that instead
of whatever presently connects the Freeway's driven sheave to the drive
axle. This would allow the torque convertor/motor to always spin in the
proper direction, with reverse being selected by engaging a gear to
reverse the rotation between the driven sheave and drive axle.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Nope, 3 phase requires 3 hot wires and a neutral coming into your house/service
entrance. If you want to redo the lines fine, but if you only have 1 phase ( 1
hot wire and 1 neutral) then it is not possible.
Rush
----- Original Message -----
From: "Ryan Stotts" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, March 09, 2005 12:29 PM
Subject: Re: AC Bandsaw motor questions
> I'm just wondering in my case, for future reference. The power lines
> in this neighborhood are all underground. Could I get 3 phase hooked
> up using the existing line that runs under the backyard to the meter
> on the back of the house?
--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.7.0 - Release Date: 3/8/2005
--- End Message ---
--- Begin Message ---
--- Roger Stockton <[EMAIL PROTECTED]> wrote:
> Note that the 3/8-16 holes don't go all the way through the endbell.
> The information you need (and that perhaps EA can provide you) is how
> deep the 3/8-16 holes need to be. If the mount came with appropriate
> 3/8-16 bolts, then you can determine this yourself. Provided you don't
> drill the hole all the way through the endbell you don't have to worry
> about aluminum shavings getting into the motor.
>
If you don't drill the hole through, BE SURE the bolt does not bottom out. If
the bolt is too
long you could press/crack the bottom of hole into the motor or the mount will
not be tight. If
you take the end off for drilling, what is wrong with drilling all the way
through? It shouldn't
have any affect on the strength and you don't run the risk of cracking the
case. If you want to
strengthen the threads you could use a thread insert, they are supposed to be
better than the
original.
Dave Cover
--- End Message ---
--- Begin Message ---
[EMAIL PROTECTED] wrote:
> bandsaw... has a Baldor 3 phase, 5 HP, 230/460V motor... I don't
> have 3 phase, so I can get a static phase converter for about $125
> from andersonconverters.com. But it will only give me about 3 HP
> instead of the 5 HP of the motor.
This is because it is not fully powering all 3 phases. A typical static
phase converter powers one phase directly from the single-phase line (so
it gets normal power); a second phase thru a series capacitor to provide
a +120 deg phase shift (so it gets only about half power); and the third
hpase thru a series inductor to provide a -120 deg phase shift (likewise
only getting about half power). The result is reduced horsepower from
the motor.
But, this many not matter in your application. The motor will run the
same speed, and still do the same basic job. You just can't load down
the saw quite as much (can't cut quite as fast or the motor will
overheat or stall).
> I also understand that it will really use amps.
Yes, that is inevitable. 5hp 3-phase draws half the current per phase as
5hp single-phase. The inevitable losses in the phase conversion make
this a little worse yet.
> Or I can trade out the motor for a new/used 5 hp, 220 V
> [single-phase] motor.
As long as it is simple to get and mount a new motor, this may be your
best choice. It will give you full horsepower, and the best overall
efficiency. However, a single-phase motor will be larger and less
efficient (run hotter) than the 3-phase motor. It's kind of like
replacing a 3-cylinder engine with a 1-cylinder engine.
> Which is my best option? Use the existing motor and get a static
> converter, or get a new 1-phase motor?
Each has its strengths and weaknesses. Buying a static phase converter
is cheaper and easier, but provides the least horsepower for the saw.
Buying a new single-phase motor for the saw is best if it is easy to
mount it.
There is a third option -- a rotary phase converter. This is the best
choice if you need full horsepower from the saw, and it is physically
difficult to change the motor. A rotary phase converter is simply a
standard 2.5-5hp 3-phase motor, with a small 1/4hp single-phase motor
coupled to it as a starter. The single-phase motor and one phase of the
3-phase motor are directly connected to your single-phase AC line. This
starts it spinning. As it does, it *generates* power on the other two
phases. Connect the 3 phases to your saw motor, and you're in business!
The rotary phase converter's motor only has to be about 2/3 the
horsepower of the saw motor. That's because only 2 of its 3 phases are
doing real "work".
Typically, you start the rotary phase converter first, then start the
saw motor. Note that you can actually have any number of other 3-phase
motors connected; with this approach, you are basically generating very
good standard 3-phase power which can be used for any purpose.
--
"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 ---
Ben Apollonio wrote:
>
> Thanks for your response.
>
> The mount is a 90-degree welded steel piece with angle pieces on the
> sides to add rigidity. The engine/tranny combo in the 914 has a total
> of four bolts holding it in the car -- two on the far end of the
> transmission at the rear of the car, and this piece, at the front of
> the motor ("front" meaning the part of the motor closest to the front
> of the car). It's definitely needed to hold the motor up, though
> *maybe* two tranny bolts could hold it temporarily if they were tight
> enough. I doubt a band clamp would work very well, since my
> understanding is that it wouldn't do a very good job preventing
> rotation, and there's really nothing else in the engine compartment to
> which one could mount the motor. I would have a very tough time trying
> to machine a proper support that would attach to a band clamp, but if
> it turns out that's the only solution...
If I recall correctly, the 914 has the "old fashioned" front-rear engine
crankshaft orientation; the shaft of the motor runs front-rear. The
engine, transmission, and differential are all mounted together as one
unit. Therefore, there is no rotational torque reaction from the motor,
as there would be if the engine was mounted separately from the
differential or transaxle. You don't have to worry about the entire
motor/transmission/differential unit trying to rotate left-right in the
car.
What you *do* have to worry about is that the entire
motor/transmission/differential assembly is connected to the wheels, and
will try to rotate in the opposite direction as the wheels. This is the
full wheel torque, which is multiplied by the gear ratio. The electric
motor's torque is bad enough -- but multiply this by 5-10 with the
transmission and differential, and you have an *astounding* amount of
torque!
Thus, you need an extremely strong set of mounts to resist this torque.
A conventional car engine, with its massively strong block, is well able
to handle this torque. But the end bell of an electric motor is not
nearly strong enough, except for fairly wimpy low-power EVs. It is only
held on with some very long skinny bolts. So, it is better if you can
devise a mount that grabs the transaxle itself -- like the old VW
Beetle. Its engine was totally mounted by the bell housing; there was no
rear mount at all.
--
"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 ---
I would like to go to wiked watts April 9 in Vegas , but it is a long
Drive . Is there enough people that want to go to get a car pool. I have a pick
up and could only take one person . I would much rather pay for gas if
possible, if not Would someone like to ride with me.
Larry Cronk Calabasas, 72 Datsun Elec Tk
--- End Message ---
--- Begin Message ---
If the holes don't get drilled all the way through the end bell, then you
actually need a pair of taps: Start with a "through" tap, which has a
tapered tip to get the threading started; then finish up with a "bottom" tap
(I think that's what they're called, anyway) which has a square tip to cut
the threads all the way to the bottom of the hole.
-- Will Bain
-----Original Message-----
From: Roger Stockton [mailto:[EMAIL PROTECTED]
Sent: Wednesday, March 09, 2005 11:37 AM
To: ev@listproc.sjsu.edu
Subject: RE: 9' ADC aft mounting holes (rather, lack thereof)
Ben Apollonio [mailto:[EMAIL PROTECTED] wrote:
> What kind of precision is required in aligning the motor in the car?
> Is this enough? What happens if the motor goes in slightly crooked,
> will things tear themselves apart? If this is good enough,
> it's almost tempting to buy a tap and just use my cordless drill
> with a 3/8" bit, though I guess I'd need to be *very* careful I was
> going at it straight and didn't mess it up.
If you go to Home Depot or similar and buy a 3/8-16 tap, you should be
able to find a package that includes the tap and the appropriate drill
bit (it will not be 3/8"). You will also need a tap handle.
If you bolt the rear mount in and bolt the front mount in, then shift
the motor as required to get the monting pads centered under the bolt
holes in the front mount, this should be good enough.
You can certainly use a handheld drill, though a drill press would be
best. Some drills have bubble levels in them, so if you drill the holes
with the motor out of the car and standing on end so that you can drill
straight down you can probably do just fine.
> Does anyone know where I can find the dimensions of that back
> plate and where the holes should be online, perhaps if I
> contact ADC?
Gordon Wong's online journal of the rebuild of the 9" in his Fiero
<http://gwinfo.net/e-fiero/re-clutching/index.htm#sep19> has lots of
good pictures of the insides and outsides of the ADC 9".
Here's a good picture showing the location of the holes. It appears as
if they are pretty much centered in the two pads:
<http://gwinfo.net/e-fiero/re-clutching/040927-07-endbell.jpg>
Note that the 3/8-16 holes don't go all the way through the endbell.
The information you need (and that perhaps EA can provide you) is how
deep the 3/8-16 holes need to be. If the mount came with appropriate
3/8-16 bolts, then you can determine this yourself. Provided you don't
drill the hole all the way through the endbell you don't have to worry
about aluminum shavings getting into the motor.
Good luck,
Roger.
--- End Message ---
--- Begin Message ---
I'll have to second rogers notion about using snowmobile cvt's.
My current snowmobile and most newer models have reverse, and the cool
part is they do it by reversing the rotation of the engine. It's really
neat. You push a button and on one of the strokes the firing order is
electronically reversed, which causes the engine to sputter like it's
going to stall and then it recover's, only it's running in the opposite
direction.
Now, having said that.....
The clutch in my sled doesn't engage until 4000rpm, kinda sux for a DC
Motor setup doesn't it. But like Roger sez I think they can be adjusted
for a much lower engagement point. The neat thing is how the CVT actually
does work. Like I said it engages a 4000 rpm. But the thing rockets me
down the trail and has a top speed of around 80mph and the engine at this
point is still only turning 6500rpm. 0-80 in about 10 sec's.
Last year at a local dragstrip the fastest vehicle there one day was an
out of the box Arctic Cat.... 1/4 in 8.6 secs at 144mph.
My sled has something like 140hp available... The belts are not an issue.
Gas is though... ~ 4 mpg. It's a shame that so much fun has to be so
dirty.
--
Stay Charged!
Hump
"Whether you think you can or think you can't, you are right!" --Henry Ford
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Roger Stockton
> Sent: Wednesday, March 09, 2005 2:42 PM
> To: ev@listproc.sjsu.edu
> Subject: RE: Comet CVT/Torque converters in a lightweight ev?
>
> Tim Medeck [mailto:[EMAIL PROTECTED] wrote:
>
>> My Freeway has a comet torque converter. It turns at all RPM, but the
>> cones don't start to close until 800 RPM. It works okay for forward,
>> but reverse stinks because the cones don't close when you reverse the
>> rotation of the converter. It backs up, but with a lot of slipping and
>> jumping of the belt.
>
> The problem your Freeway has is that the driven sheave is being turned
> backwards; the clutch sheave will close the same when rotated in either
> direction (the flyweights travel outward radially the same regardless of
> the
> direction of rotation).
>
> One side of the driven sheave is typically fixed to the shaft while the
> other side can rotate against spring tension and move away from the fixed
> sheave as it travels along some ramps. This allows the belt to ride lower
> in the driven sheave and yields a higher gear (lower reduction ratio)
> effect.
>
> The problem is that when you rotate the driven sheave opposite to its
> intended direction of rotation, the belt rotates the movable side of the
> sheave easily so that it moves away from the fixed half and results in
> less
> pressure on the sides of the belt such that the belt slips.
>
> You could fix this problem with some means of preventing the movable face
> of
> the driven sheave from moving away from the fixed face. A possiblity is a
> cable operated idler wheel that could be brought to bear against the
> backside of the movable half when in reverse that would either prevent the
> movable half from moving away from the fixed face or would at least
> greatly
> increase its resistance to movement.
>
> The 'proper' solution is probably to locate a chaincase from a snowmachine
> that was equipped with reverse gear and install that instead of whatever
> presently connects the Freeway's driven sheave to the drive axle. This
> would allow the torque convertor/motor to always spin in the proper
> direction, with reverse being selected by engaging a gear to reverse the
> rotation between the driven sheave and drive axle.
>
> Cheers,
>
> Roger.
>
--- End Message ---
--- Begin Message ---
Ryan Stotts wrote:
Christopher Robison wrote:
Mark Farver said:
The DCP DC/DC is basically no longer available. I understand that a
dozen or so are still around but that the current owner is hesitant to
put them into the retail channel. This leaves the EV industry with no
high voltage capable DC/DC products. Someone needs to start thinking
about repackaging an Vicor or Meanwell device.
I've complained about it before so I won't add too much here, other than
my agreement. This is a hole in the market that would guarantee at least
a temporary monopoly to the party that fills it.
So the situation currently is that their is not a suitable DC/DC for
the 12 volt needs in an EV?
There is the Sevcon units available from the ev parts companies, but
they are limited to about 120-144VDC input. If you want to go higher
than that (and are not using the Siemens/Metricmind AC drives with
their built in DC/DC) there isn't much currently available AFAIK.
Mark Farver
--- End Message ---
--- Begin Message ---
Tim Medeck wrote:
> My Freeway has a comet torque converter. It turns at all RPM,
> but the cones don't start to close until 800 RPM. It works
> okay for forward, but reverse stinks because the cones don't
> close when you reverse the rotation of the converter.
There must be something assymetrical about this torque converter. It was
probably designed for an ICE, which only ran in one direction.
You don't really need it to "disconnect" below 800 motor rpm in an EV.
See you you can adjust or shim it so it stays coupled, so reverse will
work better.
Or, get rid of the whole thing. The Freeway system never did work very
well. Bob Schneeviess modified a Freeway to use a fixed-speed cogged
belt, and it worked much better.
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading
Or do the great deeds worth repeating
-- Ben Franklin, Poor Richard's Almanac
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Ryan-
I don't see the numbers the same way (see prior #s below).
Since the brushes are currently wired in bunches of 4 to the 2 motor
terminals:
With 8 leads, and assuming 4 separate, parallel torque generation coils in
the PM field of an ETEK, splitting these into separately excitable windings,
the way I see it you could excite this in the following ways:
Config Vmax Imax Wmax Kb^-1
1S4P 48v 135amp 3600RPM 72RPM/V
2S2P 96 67.5 7200 36
4S1P 192 33.8 10800 18
In each case, 8HP is the continuous power rating, 160in-lb the continuous
torque and 3600RPM the no load speed max at 48v/coil.
So the net result of changing the winding configuration is the ability to
extend the power curve out to higher RPMs....anyone know at what speed such
an ETEK config will blow its rotor up?
-Myles Twete
Ryan estimated:
> > If I'm close then you would have
> > yourself a 12-24-48v motor, 18v/rpm,36v/rpm,72v/rpm motor. Although
> > it might also change current handeling capacity aswell to something
> > like [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] due to the
> > loss of
--- End Message ---
--- Begin Message ---
Roy, are you familiar with the Electric Boats YAHOO Group?
Its a great resource for electric boat converters/enthusiasts---and I just
became the moderator.
-Myles
> Hi Roy and All,
> --- Roy LeMeur <[EMAIL PROTECTED]> wrote:
> > Additionally on this subject...
> >
> > I usually tell folks to use an existing dual-cable
> > control hooked up to two
> > Curtis PB-6s.
--- End Message ---
--- Begin Message ---
I'm buying 400 cells and I'm here in Los Angeles. I
have a forklift and a commercial address. That should
help somewhat. Perhaps there would be a Norcal and a
Socal shipment.
Gadget
--- Tim Clevenger <[EMAIL PROTECTED]> wrote:
> At that weight, it may be time to shop around a bit
> as well.
>
> Where in NorCal are you? Maybe I can arrange a buy
> in SoCal and
> pick them up from your place (I get up there a few
> times a year.)
> In fact, I'm driving a truck from Sacramento to San
> Bernardino the
> first weekend of April, so if this all happens
> pretty quickly, I can
> combine trips.
>
> Anybody else in SoCal interested in a group buy?
>
> Tim
>
> ---------
> > > Date: Tue, 08 Mar 2005 20:14:09 -0800
> > From: Bryan B <[EMAIL PROTECTED]>
> > To: ev@listproc.sjsu.edu
> > Subject: Re: BB-600 Nicad Cells
> >
> >
> > I went back to freightquote and checkbox hazardous
> material, seems all
> > they wanted contact info.
> >
> > I increased the shipping weight to 2000 lbs, 4
> pallets (4'x4')
> > non-stackable gives a quote of $865. Not too bad
> compared to $525 for
> > half the weight. Cuts shipping to $432.50
> /1000Lbs.
> > I would have to pick up from Old Dominion terminal
> unless I pay extra
> > (maybe a good idea considering 2000Lbs - about
> $75-100 for delivery)
> > More weight may offer a greater individual $
> savings on shipping.
> > I can firm up the quote once the number of cells
> being transported is
> > known.
> > Why do the good buys always seem to be located on
> the east coast?
>
>
>
>
>
> __________________________________
> Celebrate Yahoo!'s 10th Birthday!
> Yahoo! Netrospective: 100 Moments of the Web
> http://birthday.yahoo.com/netrospective/
>
>
=====
visit my website at www.reverendgadget.com
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Sherry Boschert
President
San Francisco Electric Vehicle Association
415-681-7731
www.sfeva.org
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--- Begin Message ---
Since this discussion regarding Lithium and Peukert effect began, I've done
some looking at research papers online which have investigated opimal
modeling for LiPo batteries. This is a ripe area of research still. In the
process, I have found an interesting reference to 1st, 2nd, 3rd and 4-th
generation modeling of batteries. Also there are the different types of
common modeling, from the classic electrical and electrochemical models to
far more sophisticated numerical computation and computationally intensive
ones. I haven't found any research reference which offers data and modeling
to support the claim that Lithium batteries do not see effective capacity
reduction with increasing load currents.
Ryan suggested that a Lithium battery discharged at one higher rate will
subsequently yield more energy at a lower rate, etc. I pointed out how PbA
batteries exhibit this effect as well. Ryan claims that this is not the
case "due to Puckerts":
> Right, but I was under the impression that at high rates PbA will only
> deliver a fraction of it's lower rate nameplate capacity. After such
> a high rate discharge you can't lower the rate and get the other half
> of it's capacity out because it's lost due to Puckerts.
This is not true.
Even at low 0.1C rates of discharge on my boat (45amps of 450Ah), the
batteries show a voltage sag. Removing the load, or reducing it, causes the
voltage to rebound. This is indisputable. And in fact, running on mere
electrons at 15amps with one 225Ah string, with only 24v of 36v rating,
reducing the current to 10amps caused the voltage to increase, allowing me
to go another mile or so before the battery voltage dropped back down to
that level seen at 15amps.
No, rather than Lithium magically being able to deliver more energy after
removing or reducing the load once a target discharge voltage is reached,
ANY electrochemical battery exhibits this effect. Emil pointed out why by
pointing out that the speed of electrochemical reaction in batteries is
limited "in each case". Look at several good research papers on Lithiums
right now and you'll see lots of modeling done on just these reactions,
reaction rates and lags.
The effect you are referring to, Ryan, is called "rebound".
Electrochemically, it is due to the delayed reaction in the chemicals
flowing in/out of the boundaries or materials in the battery until stasis is
reached. This reaction rate differs between battery chemistries, but is
there in all---and it creates a lag time, which ALLOWS extra energy to be
extracted after what seemed to be battery depletion to a target discharged
level.
NOTE: The Peukert battery capacity vs discharge rate model DOES NOT model
REBOUND EFFECT!
It's a simple, "2nd generation" battery model and in so being, doesn't
include the rebound.
Many battery models do not model rebound.
But ALL electrochemical batteries exhibit it.
Finally, from one study I read that not only do Lithium batteries show
reduced effective capacity as a function of load current (just like NiMH,
PbA, etc.), but "pulsed" load currents show a SIGNIFICANTLY greater impact
on Lithium battery capacity than their averaged current!
An example for a Lithium rechargeable (from "The impact of Battery Capacity
and Memory Bandwidth on CPU-Speed setting: A Case Study", by Martin and
Siewiorek of Carnegie Mellon University) shows that for a continuous
specific battery load of 75w/kg yielded a battery life of 1.9hours. AND
YET, with the same battery, an intermittent load of 4-times the peak
current, but with the same AVERAGE current of 75w/kg load, showed only
1.3hours (31%less)of discharge time! They further noted that only with load
levels below 50w/kg did the pulsed load yield a total effective battery
capacity as the equivalent continuous load.
This is an important factor for EVers using Lithiums with dynamic battery
loads, and shows conclusively that Lithium batteries are not immune to
battery loading.
-Myles Twete
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The key distinctions here are "high voltage" ( > 200V input), and
"automotive" (intended for SLI usage in an automobile).
There have been many good ideas posted here very recently about what would
make a good DC/DC; I think something sealed and watertight that provides
75-100A at 14V when active and acts as an intermittent battery charger
(charging only when necessary) when inactive would be a huge step in the
right direction.
I don't know of anything that fits this description, at any input voltage.
There are more basic non-automotive-specific units available (eg. the Iota
supplies, etc), but nothing for folks running at higher voltages. At 348V,
I'll have no really good options off the shelf.
In recent discussions with knowledgeable folks I've been clued in as to
why this is such a difficult thing to produce (at a reasonable price), but
still I'd like to think of this as an "opportunity" for certain well-known
quality-minded individuals.... :o)
--chris
Ryan Stotts said:
>>Christopher Robison wrote:
>> Mark Farver said:
>>
>> > The DCP DC/DC is basically no longer available. I understand that a
>> > dozen or so are still around but that the current owner is hesitant to
>> > put them into the retail channel. This leaves the EV industry with no
>> > high voltage capable DC/DC products. Someone needs to start thinking
>> > about repackaging an Vicor or Meanwell device.
>>
>> I've complained about it before so I won't add too much here, other than
>> my agreement. This is a hole in the market that would guarantee at
>> least
>> a temporary monopoly to the party that fills it.
>
> So the situation currently is that their is not a suitable DC/DC for
> the 12 volt needs in an EV?
>
>
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Christopher Robison wrote:
> that provides
> 75-100A at 14V when active and acts as an intermittent battery charger
> (charging only when necessary) when inactive would be a huge step in the
> right direction.
In my setup, I just want to run the DC/DC with it wired directly to
the fuse panel with no accessory battery. I'll have LED lights front
and back, the horn, I'll wire up the wiper motor "just in case", an
E-meter, a tach, gauge lights for night time use; that's all the
accessory load I can think of. I wonder how many amps all that will
sap off my pack? What size DC/DC would be needed to support all that?
> In recent discussions with knowledgeable folks I've been clued in as to
> why this is such a difficult thing to produce (at a reasonable price),
What are the hindrances to making a DC/DC that supports higher pack
voltages? I'm unaware to what the difficultly might be.
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I was wrong here:
> Config Vmax Imax Wmax Kb^-1
> 1S4P 48v 135amp 3600RPM 72RPM/V
> 2S2P 96 67.5 7200 36
> 4S1P 192 33.8 10800 18
For the ETEK hypothetical brush rewiring craziness, I made a mistake.
The speed column is WRONG...Wmax instead is 3600RPM in each case...i.e.:
Config Vmax Imax Kb^-1 Kb Kt
1S4P 48v 135amp 72RPM/V 13.9v/kRPM 1.18 lb-in/amp
2S2P 96 67.5 36 27.8 2.36
4S1P 192 33.8 18 55.6 4.72
These remain unchanged:
Wmax = 3600RPM
Tmax = 160lb-in
So what would be the advantage in any dynamic 'rewiring' of this motor since
the top speed remains unchanged?
Someone may find it useful to use the ETEK at higher voltages...ahh, so
perhaps that's the benefit: Run at 96 or 192v as a drag vehicle race motor
with the ability to briefly dump 150amps or so from a 96v pack, for the
equivalent torque you'd get with 300amps from a 48v pack. Advantage?
-Myles Twete
>
> In each case, 8HP is the continuous power rating, 160in-lb
> the continuous
> torque and 3600RPM the no load speed max at 48v/coil.
> So the net result of changing the winding configuration is
> the ability to
> extend the power curve out to higher RPMs....anyone know at
> what speed such
> an ETEK config will blow its rotor up?
>
> -Myles Twete
>
> Ryan estimated:
>
> > > If I'm close then you would have
> > > yourself a 12-24-48v motor, 18v/rpm,36v/rpm,72v/rpm
> motor. Although
> > > it might also change current handeling capacity aswell to
> something
> > > like [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] due to the
> > > loss of
>
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Joe Smalley wrote:
> In order to build a flexible motor like you describe, you must
> change the field polarity on each segment of the field separately.
> You cannot do this with a PM motor but you can do it with a wound
> field motor.
Yes, this is normally true. However, there *are* PM motors that have 4
brushes, and are wound with so they function as two independent
armatures that you can connect in series or parallel. They do this when
then need two different speeds, or need to have one motor that runs the
same speed on either 12v or 24v. For such a motor, you do not need to
change the magnets.
--
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
-- Leonard Cohen, from "Anthem"
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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Look at these in general
http://vicr.com/library/technical_documentation/datasheets/2nd_gen/
and at this one in particular
http://vicr.com/documents/datasheets/V375A12C600A.pdf
You will get 40A-45A out from Maxi series
Vicor also makes 14.3V (+/-) nom output DC-DCs but it is not
their standard line.
--
Victor
'91 ACRX - something different
Christopher Robison wrote:
I don't know of anything that fits this description, at any input voltage.
There are more basic non-automotive-specific units available (eg. the Iota
supplies, etc), but nothing for folks running at higher voltages. At 348V,
I'll have no really good options off the shelf.
--chris
Ryan Stotts said:
Christopher Robison wrote:
Mark Farver said:
The DCP DC/DC is basically no longer available. I understand that a
dozen or so are still around but that the current owner is hesitant to
put them into the retail channel. This leaves the EV industry with no
high voltage capable DC/DC products. Someone needs to start thinking
about repackaging an Vicor or Meanwell device.
I've complained about it before so I won't add too much here, other than
my agreement. This is a hole in the market that would guarantee at
least
a temporary monopoly to the party that fills it.
So the situation currently is that their is not a suitable DC/DC for
the 12 volt needs in an EV?
--
Victor
'91 ACRX - something different
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Roderick Wilde wrote:
> I am personally looking forward to the day when we can have a
> double A class which would be above 360 volts since that is the
> current limit of DC cars. I don't see DC going much above that.
> It's not that efficient up there. The future of electric drag
> racing is in AC so I could logically assume up to and beyond
> 600 volt machines.
Are there AC motors out now that have the performance potential that
you have in mind?
If the motors available now are listed as having a max current rating
of "400 amps", is that a "hard limit", as in; it REALLY is limited to
400 amps? Or is that just the factory under rating their stuff and it
can really take at least double that? ;) Just how many amps can
these water cooled AC motors take?
What's it going to take to get some lower cost high amp inverters made
for AC setups?
When do you see the AC revolution taking place? This year, or next or?
If current high performance DC motored street EV's can run 13's with
12's being possible, what type of performance can be expected with AC
setups? 12's to begin with or better or?
Thanks for any info.
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