EV Digest 2855
Topics covered in this issue include:
1) Re: A new EV begins
by [EMAIL PROTECTED]
2) Re: A new EV begins
by "garry" <[EMAIL PROTECTED]>
3) battery charging
by "garry" <[EMAIL PROTECTED]>
4) Re: Wheelmotors
by "1sclunn" <[EMAIL PROTECTED]>
5) Re: Wheelmotors
by Gordon Niessen <[EMAIL PROTECTED]>
6) Re: Ampabout
by "John G. Lussmyer" <[EMAIL PROTECTED]>
7) Re: S-10 conversion advise
by "1sclunn" <[EMAIL PROTECTED]>
8) Re: Ampabout
by Aaron Birenboim <[EMAIL PROTECTED]>
9) Re: Wheelmotors
by Michael Hurley <[EMAIL PROTECTED]>
10) Auranthetic parts
by Chip Gribben <[EMAIL PROTECTED]>
11) Re: Wheelmotors
by "Mark Thomasson" <[EMAIL PROTECTED]>
12) This is a MUST READ LA Times Article
by "Steven S. Lough" <[EMAIL PROTECTED]>
13) New Yahoo Group for Evercel Nichel-Zinc Batteries
by "Tom Hudson" <[EMAIL PROTECTED]>
14) EV Meter
by [EMAIL PROTECTED]
15) Re: battery charging
by "1sclunn" <[EMAIL PROTECTED]>
16) Re: wheel motor
by Sam Harper <[EMAIL PROTECTED]>
17) Re: wheel motor
by Sam Harper <[EMAIL PROTECTED]>
18) Re: battery charging
by "garry" <[EMAIL PROTECTED]>
19) Re: wheel motor
by Peter VanDerWal <[EMAIL PROTECTED]>
20) Re: New Yahoo Group for Evercel Nichel-Zinc Batteries
by Seth <[EMAIL PROTECTED]>
21) Re: Lowest frequency (was Re: AC vs DC)
by Rich Rudman <[EMAIL PROTECTED]>
22) Re: Lowest frequency (was Re: AC vs DC)
by Rich Rudman <[EMAIL PROTECTED]>
23) Ultralife LiPolymer?
by "Coallier, Steve" <[EMAIL PROTECTED]>
24) Re: wheel motor
by Sam Harper <[EMAIL PROTECTED]>
25) Re: New Yahoo Group for Evercel Nichel-Zinc Batteries
by "Jon \"Sheer\" Pullen" <[EMAIL PROTECTED]>
--- Begin Message ---
> I didn't put the clutch in because it is a huge chunk of weight which would
> be compounded by the bearing system needed to properly mount it, as I doubt
> my motor or anyone's motor for that matter, has a thrust bearing
> specifically designed for the end pressure applied to the motor shaft when
> the clutch is applied.
There is so much ignorance concerning bearings. Some people on the Sparrow
list think the bearings aren't sized adequately for the side loading caused by
the belt. As I recall the output bearing on the Prestolite MTC4001 is 35mm ID
and has a radial loading capacity of about 2500 Kg, the axial (thrust) loading
capacity would be approx. 25% of this figure. Take a look at a typical clutch
release (throwout) bearing, it's taking exactly the same loading as the motor
bearing and many are based on conventional deep groove bearings, not thrust.
The Sparrow does have motor output bearing problems, but I think that's down to
the shaft bending and subjecting the bearing to misalignment.
Paul Compton
BVS technical officer www.bvs.org.uk
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
Hi Paul,
Coming from an automotive background im very aware of the strains and
stresses put on bearings by load and the consequences.
If as you say sparrow motors are experiencing bearing problems then perhaps
when replacing them you could do what we did for Mazda rx7's when we raced
them.
These cars are small and have a lot of horsepower but little torque so Mazda
got away with very light axles, but in race conditions we found that the
axles flexed using the bearing as a pivot and broke just behind the bearing.
The fix for this turned out to be rather simple and may well be just as easy
here.
What we did was buy a double race bearing the same size as the axle bearing
and make a housing to contain its extra length, then fitted this to the
axle, not only does the bearing become twice as durable, but the axle and
bearing are no longer able to flex and it doesn't break anymore.
This would also double the thrust loading of the bearing for other
applications.
Hope this helps you out with your sparrow problems.
Garry Stanley
Cable.net.nz
--- End Message ---
--- Begin Message ---
Hi folks,
Well I have my car built, and while I cant say im disappointed with its
performance its nothing to write home about.
I have the original charger that went with the forklift and its set for an
11 hour cycle which is probably overkill for my batteries.
The batteries are to the best of my knowledge rated at 135 amp hours and the
charger puts out 30 amps.
After a few hours of charging the amp draw drops down to 20 amps and the
batteries are warming and even though sealed are making a nice bubbling
noise.
Not wanting to damage them especially on the first charge I stopped here and
ran the car around the block for 10 k's till they were flattish again and
started recharge.
I recharged for 2 hours on Friday and again added another 2 hours today, at
the end of today's charge the amps were down to 15 amps.
With this simple setup should I treat it like a normal battery and consider
it charged when the amp draw closes in on nothing or should I stop charging
well before it drops near 0 amps draw ?
Garry Stanley
Cable.net.nz
--- End Message ---
--- Begin Message ---
The new model of the lawn mower I use has this ( dixie chopper) and the
wheel is even supported by the Hydraulic motor shaft . They have the wheel
hub right on the motor shaft and the hydraulic motor is then mounted to the
frame. I have heard that you need 2.5 hp in to get 1 hp out with hydraulic
motors ,don't know this for sure.
Steve Clunn
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, June 14, 2003 11:32 AM
Subject: Re: Wheelmotors
> Sam Harper wrote:
> >
> > Has anyone had any success in finding a wheelmotor that is both
> > powerful enough but economical?
>
> Does it have to be electric? There are thousands of wheel motors in
> service in off-road truck, industrial vehicles, and construction
> equipment. They use hydraulic motors, which are small, light, and have o
> problem delivering very high torques at low speeds.
>
> You'd need an electric motor driving an oil pump to run them. This again
> is standard off-the-shelf technology, used in thousands of fork lifts,
> garden tractors, etc.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
>
--- End Message ---
--- Begin Message ---
At 12:34 AM 6/15/2003, you wrote:
Lee Hart asked:
<snip>
#9-5389 -- Parker TG0280SS080AGAU Wheel motor with integral brake, 266
rpm at 20 gpm continuous, 7301 in.lbs torque continuous, 9707 in.lbs
torque peak, 3000psi continuous, 4000 psi peak, 68 lbs, $315.99.
#9-3557 -- Ross wheel motor, 252 rpm at 20 gpm continuous, 334 rpm at 25
gpm max, 4502 in.lbs torque continuous at 2000 psi, 7029 in.lbs torque
peak at 3000 psi, 37 lbs, $279.50.
<snip>
I guess you are looking at either really big wheels or some sort of gearing
to get to rpm's to convert to 55mph.
--- End Message ---
--- Begin Message ---
At 12:18 AM 6/15/2003 -0700, Chuck Hursch wrote:
I have one of those expanded-scale SOC gauges (just a voltmeter)
in the VoltsRabbit. I in fact do find it quite useful to tell me
the internal resistance of the pack. As we all do, I drive the
At one time, someone on this list described an interesting and simple SOC
meter that gave useful results. It was 2 Analog meters, one for current,
one for voltage, pointed at each other in the same case. i.e. one mounted
180 deg rotated from the other. This let their needles cross (without
hitting!).
Max voltage and 0 current were at the same end of the scale. (say, with
meters mounted left-right, both needles at the top.) You then watched the
intersection of the 2 needles. Further left was good, right was bad.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream.... http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
Hi Mark Glad your thinking about an EV , have you been for a ride in one ?
what kind?
> I am about to undertake my first EV conversion. I have a 92 S-10 with a
> dead IC motor. My requirements for the conversion are split into two
> scenarios dependent on attainable range.
This is a good one if it has a manual tranny
> Scenario 1:
> Consistent range in excess of 75 miles on uneven terrain.
> In this case the truck could become my daily commute car. I drive ~60
> miles each way to my Daughter's school---->work. At this point I would
> have 220v available for a charge while at work. Work ---->home is ~45
> miles.
60 miles is not an easy bill to fill and I'm sure you don't want to drive 30
mph . Like making a gas car go over 140 mph ,. can be done but the money
cruve will be there
> The terrain crosses a range of coastal hills from the Sonoma Valley to
> the Napa Valley.
This will use more also
> Scenario 2:
> Less range, used as mainly a weekend car, errands etc. would become
> main weekend transportation. Would be a lot less uesful, as 90% of my
> driving is back and forth to work...
This would be easy and if somthing happened to the gas car that you could
use your Ev .
>
> I have reviewed a "kit" conversion, and spoken with another converter
> with a "generic" kit. Neither made me comfortable with their range.
They don't want you to end up with somthing that dosn't work for you , Seems
to be the thing now with EV's to under state the range. I often tell people
mine has a 30 mile range even though I one time drove it 76 miles at the
Sunday challenge EV rally. I also drove my EV mercury Lynx 90 miles to the
rally one year (the next day the 76mile drive was a piece of cake) . Both
these are/were (lynx was re in car nated to a Mitsubishi truck) 120v golf
cart bat setup.
>
> I guess my question is, how can I extend the range 10-15 miles? Both of
> these kits seem to be slightly older tech, but very easy and proven
> components. Both seem to reject re-gen, or other "slick" range
> extending tactics.
Sounds like they are giving you the "straight talk" which is what you want.
Do you have the money?/// :-) 30 to 40 golfcart batteries and Victors ac
motor come to mind ,
> I have considerable IC engine experience, have restored cars, rebuilt
> motors, done engine swaps, race a Volvo currently, so the hardware side
> of the conversion doesn't intimidate me.
You will love working on EV's then , nice and clean
> As far as electrical experience? Well, I have a tendency to let the
> smoke out of things. I can learn, but do not want to make unnecessary,
> expensive mistakes.
You don't have to be an EE and if your good with IC's you'll pick it up fast
.
> Would this be a recommended project for a first time EV'er?
Probable not but if you said you were going to tow a 1500 lbs trailer 30
miles a day for your first EV people would advise agenst it also , that was
10 years ago for me .
What will happen if you go with No 2 is when you get it done you will love
it so much you'll want to drive it all the time . I gave up my back up gas
car 2 years after my first EV so I could have another EV.
I now also have a need to drive 80 miles and am trying to figure a way (
even though the min speed limit is 40 mph they don't like you drive it on
the hi way) .
> Offline response is ok....
This is stuff I thing people want to know about why not keep it on the list?
Steve Clunn
www.grassrootsev.com
>
> Thanks for any help,
>
> Mark Osborne
> Sebastopol, Ca
>
> __________________________________
> Do you Yahoo!?
> SBC Yahoo! DSL - Now only $29.95 per month!
> http://sbc.yahoo.com
>
--- End Message ---
--- Begin Message ---
John G. Lussmyer wrote:
At 12:18 AM 6/15/2003 -0700, Chuck Hursch wrote:
At one time, someone on this list described an interesting and simple
SOC meter that gave useful results. It was 2 Analog meters, one for
current, one for voltage, pointed at each other in the same case....
yea. he's here in ABQ...
http://www.qsl.net//k5lxp/ev/evgauge/evgauge.html
--
Aaron Birenboim | This space available!
Albuquerque, NM |
aaron_at_birenboim.com |
>http://aaron.boim.com |
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
#9-5389 -- Parker TG0280SS080AGAU Wheel motor with integral brake,
266 rpm at 20 gpm continuous, 7301 in.lbs torque continuous, 9707
in.lbs torque peak, 3000psi continuous, 4000 psi peak, 68 lbs,
$315.99.
#9-3557 -- Ross wheel motor, 252 rpm at 20 gpm continuous, 334 rpm
at 25 gpm max, 4502 in.lbs torque continuous at 2000 psi, 7029
in.lbs torque peak at 3000 psi, 37 lbs, $279.50.
Michael Hurley wrote:
Those are the wheel motors, not the variable output hydraulic pump.
It's the pump that was the really expensive part.
From the same catalog:
#9-4927-D -- Delta model PC variable displacement pump, 3500 psi
continuous, 0-37 gpm at 2400 rpm, 0-49 gpm at 3000 rpm max, 50 lbs,
$725.00.
#9-4323 -- New Eaton-Cessna 78343RAL variable displacement tandem pump.
Levers control speed, direction, and dynamic braking of each pump.
Equipped with tow valves on both pumps. 37 gpm at 3600 rpm, 3000 psi
continuous, 4500 psi max, 66 lbs, $999.00.
Note that these pumps are big enough to drive several of the wheel
motors, so the pumps actually cost less than the wheel motors.
OK, so from between 1300 and 1700 dollars. And the whole setup would
weigh from about 125 - 200 Lbs. Not too bad. A bit more expensive and
heavier than your average transmission, though. The real kicker would
be speed. Direct connection of either of these motors would give a
top speed of under 40 MPH with a 16" wheel. Not very practical in
real world use. You have one in there that has a speed of about 800
RPM and still has useful torque? Like minimum 1800 In/Lbs? What about
a simple hydraulic pump, one that can be driven off a small
motor/controller combo?
--
Auf wiedersehen!
______________________________________________________
"..Um..Something strange happened to me this morning."
"Was it a dream where you see yourself standing in sort
of Sun God robes on a pyramid with a thousand naked
women screaming and throwing little pickles at you?"
"..No."
"Why am I the only person that has that dream?"
-Real Genius
--- End Message ---
--- Begin Message ---
Anyone know where I can get a keyswitch and a meter for the Auranthetic?
A friend dropped one by for me to fix up and I got it running again. It's a
blast to ride. I'm using a temporary keyswitch but would like something
closer to the original. The original meter is shot, rusted and has been
painted over, so I need to find another one of those.
Thanks,
Chip Gribben
--- End Message ---
--- Begin Message ---
.........................................
>
> The Lemco motors are oddly built. They only have bearings at one end, so
> the shaft is poorly designed for side loads. .....it's
> not a good setup for high shaft loads or shock and vibration.
> --
Does this statement apply to the Etek motor:
Motor, LEMCO designed, 24 to 48 volt Etek by Briggs & Stratton, 7/8" keyed
shaft - Item #MT5117
http://www.evparts.com/shopping/product_details.php?id=527&product_id=1592&P
HPSESSID=989512863e3ba8e54c915070085ee6df
I'm planning to put one of these on a motorcycle with a sprocket and chain
off the motor shaft. I would consider this a high shaft load. Thanks,
Mark T.
--- End Message ---
--- Begin Message ---
* LP8.2: HTML/Attachments detected, removed from message *
--- End Message ---
--- Begin Message ---
I went ahead and set up a Yahoo Group for discussion of Evercel NiZn battery
technology with an emphasis on EV applications. I belong to a similar group
for Saft NiCds and it's great for focusing on just that technology -- Not a
lot of traffic on that list but when a question comes up, people respond
very quickly -- No "noise" from non-NiCd traffic. This is not a "snub" to
the EV List, but a way for those of us looking at NiZn technology to have a
dedicated discussion area.
Since the Evercel technology is relatively new, and some of us are working
them into existing EVs I think this group will be a good way for all of us
to share info, ideas and solve problems.
To join the group, go to:
http://groups.yahoo.com/group/Evercel-EV
I hope to see you there.
-Tom
Thomas Hudson
http://portdistrict5.org -- 5th District Aldermanic Website
http://portev.org -- Electric Vehicles, Solar Power & More
http://portgardenclub.org -- Port Washington Garden Club
http://portlightstation.org -- Light Station Restoration
--- End Message ---
--- Begin Message ---
You know,
I REALLY like this idea. This is something simple but really useful. I'm not
an electrical engineer (not by a long shot) but I think I could really get some
use out of something like this.
Any of the EE's on this list intersted in a little joint project with a newbie
to make one of these for my car?
James
Quoting Aaron Birenboim <[EMAIL PROTECTED]>:
> John G. Lussmyer wrote:
> > At 12:18 AM 6/15/2003 -0700, Chuck Hursch wrote:
> >
>
> > At one time, someone on this list described an interesting and simple
>
> > SOC meter that gave useful results. It was 2 Analog meters, one for
> > current, one for voltage, pointed at each other in the same case....
>
> yea. he's here in ABQ...
>
> http://www.qsl.net//k5lxp/ev/evgauge/evgauge.html
> --
> Aaron Birenboim | This space available!
> Albuquerque, NM |
> aaron_at_birenboim.com |
> >http://aaron.boim.com |
>
>
--- End Message ---
--- Begin Message ---
From: "garry"
>
> Well I have my car built, and while I cant say im disappointed with its
> performance its nothing to write home about.
I don't count any of the stuff I did before my first 9" motor as an EV , I
am lucky I didn't give up after a VW with 3 golf cart motors ran so poorly .
Your setup sounds a lot better that this at 72 volts and a real controller
'.
> I have the original charger that went with the forklift and its set for an
> 11 hour cycle which is probably overkill for my batteries.
For some reason I though you were up on all this batterie stuff. That
charger my be set up just to charge the batteries when they are all the way
empty
> The batteries are to the best of my knowledge rated at 135 amp hours and
the
> charger puts out 30 amps.
Are these the standard golf cart bats? they are 220 amp hours ?
> After a few hours of charging the amp draw drops down to 20 amps and the
> batteries are warming and even though sealed are making a nice bubbling
> noise.
I would be looking more at the voltage , but this dosen't sound like they
are charged . Were they gassing?
> Not wanting to damage them especially on the first charge I stopped here
and
> ran the car around the block for 10 k's till they were flattish again and
> started recharge.
Flattish , dose that mean you could "feel" less pull? we need some voltage
reading here.
> I recharged for 2 hours on Friday and again added another 2 hours today,
at
> the end of today's charge the amps were down to 15 amps.
sounds like you need to charge more . Voltage reading
> With this simple setup should I treat it like a normal battery and
consider
> it charged when the amp draw closes in on nothing or should I stop
charging
> well before it drops near 0 amps draw ?
>
There not going to drop to 0 maybe 2 to 5 amps depending on the shape there
in and the charger. Voltage should be between 14to 15 volts (per 12v block)
depending on charger and how old they are.
Steve Clunn
> Garry Stanley
>
> Cable.net.nz
>
--- End Message ---
--- Begin Message ---
I agree, but isnt the problem with Lemco sized motors tied directly to
wheels is that they lack a torque range capable of accelerating a car
with any speed. Since a CVT is continuously variable you can keep the
electric motor at its highest power output level for an infinite amount
of time by simply changing the gearing as you accelerate. When
cruising, simply change the gearing so that the motor is at the most
efficient point. Am I wrong?
-Sam Harper
On Sunday, June 15, 2003, at 01:29 AM, Peter VanDerWal wrote:
CVTs are a good idea with ICEs because you can make up for the
(relatively) lousy efficiency of the CVT by keeping the ICE in it's
sweet spot.
Electric motors have much broader sweet spots and the difference
between
maximum efficiency and the efficiency through most of the torque range
is pretty small.
CVTs are a BAD idea with electric motors. There are much better
solutions available that are lighter, cheaper, more reliable, and much
more efficient.
On Sat, 2003-06-14 at 16:51, Sam Harper wrote:
Wheel motors are fairly light. The Lemco LEM-2x2 is only 22 kilos,
with a CVT being approximately 15-20 kilos, even on four wheels you
have less weight than a motor, transmission, drive-shaft, etc. What I
talk about isnt actually an in-wheel or hub motor, but one that is
just
directly connected to the individual wheel via a CVT.
-Sam Harper
On Saturday, June 14, 2003, at 07:19 PM, Jeff Shanab wrote:
Isn't a wheel motor a move in the wrong direction? won't all
that
unsprung weight make wheel control a nightmare? ( i guess with enough
lead you can get the ratio of sprung to unsprung back in balance.)
BTW Hydraulic motors and pumps are very inefficient :-( Why not
change the upright to one from a front wheel drive mid size, like a
pontic grand-am. and use half shafts. Isn't torque an issue with
wheel motors? generally requiring all 4 wheels to be done?
how would a wheel motor stand up to road vibration in an EV at
highway
speeds?
--
EVDL
--- End Message ---
--- Begin Message ---
James,
I really like this idea. I would like to see a car with four
Lemco/ETEK motors connected to electronic CVTs connected directly to
wheels. They could be powered by slave curtis' or by BLDC drives
centrally controlled by an onboard computer. The accelerator and brake
pots could send information to the computer [maybe even a drive-by-wire
steering system, too]. Acceleration, braking, and ABS could all be
done electronically, with caliper brakes as backup. By removing some
of these legacy components we lighten the car and make more space for
batteries. We also gain more regenerative electricity.
-Sam Harper
On Saturday, June 14, 2003, at 07:56 PM, James Rice wrote:
I'm having problems replying to the list at the mo - but I wrote this
earlier
this evening...
<-- Snip - earlier failed message -->
Going down the wheel motor train of thought for a moment...
Lee wrote:
Wheel motors are a "holy grail" that bright but naive inventors
always seem to
pursue.
Bright but naive is a slightly negative way of putting things, but my
BEng
Automotive Engineering Design final project was titled, "Suspension And
Drivetrain For An Electric Vehicle," so I guess I want to defend one
of my
design routes :^D
Studying the inertia of the drivetrain in a conventional vehicle,
shows just how
much energy is transferred into kinetic energy, which even a very good
regenerative braking system cannot fully recover (I've read that a 5%
to 15%
increase in range from regen is typical, which disappoints me, but
equally
doesn't surprise me). [The Electric Car, Michael H Westbrook,
Institute of
Electrical Engineers, ISBN 085296 013 1]
Regarding inertia - http://www.violetliquid.co.uk/Izz2.xls is an
approximated
breakdown of the inertia of a Fiat X1/9 wheel, tyre, brake disk, hub
and
half-shaft. This is a light wheel (and an average narrow tyre) though
there can
be significant weight savings made in the half-shaft using composite
materials
(actually the weight of the half-shaft was based on that of a Toyota
Celica
Supra 2.8 injection... But it's still an approximation anyway!)
The basic problem with wheel mounted motors is the transfer of weight
to
unsprung mass, despite the weight saving of the half-shaft
(semi-sprung anyway)
and maybe one or two other components dependant on your design. As I'm
sure
we've discussed here in the past unsprung mass has a huge effect on
handling.
Cutting down to its simplest level, the greater the unsprung mass, the
harder it
is to keep the wheel in contact with the ground.
Sam Harper wrote:
Instead of using one main motor with a large controller,
has anyone make a vehicle with 2 or 4 smaller independent
direct-to-wheel motors?
As Sam clarified, he was talking wheel per motor... Now this is a
perfect
solution, torque and speed of each wheel can be controlled by
software, as per
the steering wheel position, drivers preference (gentle oversteer
please) and
accelerator position (plus maybe a gyroscope type of system - like a
Skyline -
which measures the current acceleration direction and magnitude of the
car).
This isn't a great way for home builds right now because it is another
layer of
controllers and sensors - but once a few companies begin to produce
off the
shelf controllers, we can all make some amazing handling cars. The
other
advantages include the fact that there is already the proven wheel and
brake
technology which can be purchased off the shelf.
Lee wrote:
But CVTs are expensive, and have relatively low efficiency.
Which is a shame, because they're a fantastic idea. Modern ones aren't
so bad in
efficiency terms - gone are the days of the slipping rubber bands in a
DAF.
Lee wrote:
As a rule, one large motor is cheaper, lighter, and more efficient
than
many small motors. Same for controllers and transmissions.
Differentials
and driveshafts look hokey, but are actually a pretty good solution.
A limited slip diff is fine, but old fashioned diffs which drive a
single wheel
and let the other trail only lead to sideways take-offs. For most
driving a
standard diff is fine, but as soon as you go to a track day, or reach
the limit
(by accident or otherwise) on the road, you'll wish you had an LSD or
a motor
per wheel :^D
James
This has got me all excited! I can write the software required to
control the
motors, but I need to know more about the hardware... I'm going to
look at
controllers :^P
</--snip message -->
----- Original Message -----
From: "Sam Harper" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, June 15, 2003 12:51 AM
Subject: Re: wheel motor
Wheel motors are fairly light. The Lemco LEM-2x2 is only 22 kilos,
with a CVT being approximately 15-20 kilos, even on four wheels you
have less weight than a motor, transmission, drive-shaft, etc. What I
talk about isnt actually an in-wheel or hub motor, but one that is just
directly connected to the individual wheel via a CVT.
-Sam Harper
On Saturday, June 14, 2003, at 07:19 PM, Jeff Shanab wrote:
Isn't a wheel motor a move in the wrong direction? won't all that
unsprung weight make wheel control a nightmare? ( i guess with enough
lead you can get the ratio of sprung to unsprung back in balance.)
BTW Hydraulic motors and pumps are very inefficient :-( Why not
change the upright to one from a front wheel drive mid size, like a
pontic grand-am. and use half shafts. Isn't torque an issue with
wheel motors? generally requiring all 4 wheels to be done?
how would a wheel motor stand up to road vibration in an EV at highway
speeds?
--- End Message ---
--- Begin Message ---
Hi Steve,
I've charged my share of batteries, but never this many together at once.
My mobility scooter is charged when the battery amp draw goes down to under
5 amps on an 8 amp charger but I was concerned that this was not necessarily
so on a larger pack.
I believe the batteries are 135 amp hour but they are the same weight and a
little larger than t105's.
Their normal use is for emergency lighting and computer back up systems
rather than high drain like an ev, but at $10 each instead of $175 each they
are better than nothing and have worked quite well on my toer over the last
few months.
As this is a forklift charger my guess is it is set to give a full charge
when the forklift is drained and I assumed that an 11 hour cycle with a 30
amp rating would be to charge 300 odd amp hours of batteries but of course
the amps fall off so maybe it only had a 150 amp hour set like the toer
which is from a similar era.
Flattish means it was still going but not accelerating in the higher gears,
it seems to have some protection built in and when getting flat it will cut
out in top gear and then eventually in 3rd gear and when this first happened
it didn't have the power to get the wheels over a little rise at the door
without a push.
Because these have gone flat while sitting I thought that charging for a few
hours and then running down and charging again would be a quick way to get
the batteries evened out and working as a string, but this time around im
going to let them go to below 5 amps cause I want to get some idea of range.
After 4 hours this time they are now below 10 amps and today I will give
them another couple of hours and once I establish what the charge time is I
will reset the charger to run for this time rather than leaving it and
hoping fro the best.
Garry Stanley
Cable.net.nz
--- End Message ---
--- Begin Message ---
> I agree, but isnt the problem with Lemco sized motors tied directly to
> wheels is that they lack a torque range capable of accelerating a car
> with any speed. Since a CVT is continuously variable you can keep the
> electric motor at its highest power output level for an infinite amount
> of time by simply changing the gearing as you accelerate. When
> cruising, simply change the gearing so that the motor is at the most
> efficient point. Am I wrong?
No, the problem is that a single Lemco isn't powerful enough for
anything other than a motorcycle or very small (or very slow) car.
Adding a CVT will rob you of nearly half the Lemco's power making it
even less suitable.
Even you are using the Lemco in a vehicle where it's not powerful enough
for a single speed transmission, then use a manual multispeed
transmission. However you will STILL be limited by how much power it
can produce. A single Lemco-200 in a 3,000 lb EV will be fine as a
parking lot cruiser but will never make it to highway speed, regardless
of transmission.
--- End Message ---
--- Begin Message ---
Tom-
Would you mind sharing a URL for the NiCd group? I didn't manage to find it.
Thanks!
Seth
Tom Hudson wrote:
>
> I went ahead and set up a Yahoo Group for discussion of Evercel NiZn battery
> technology with an emphasis on EV applications. I belong to a similar group
> for Saft NiCds and it's great for focusing on just that technology -- Not a
> lot of traffic on that list but when a question comes up, people respond
> very quickly -- No "noise" from non-NiCd traffic. This is not a "snub" to
> the EV List, but a way for those of us looking at NiZn technology to have a
> dedicated discussion area.
>
> Since the Evercel technology is relatively new, and some of us are working
> them into existing EVs I think this group will be a good way for all of us
> to share info, ideas and solve problems.
>
> To join the group, go to:
>
> http://groups.yahoo.com/group/Evercel-EV
>
> I hope to see you there.
>
> -Tom
>
> Thomas Hudson
> http://portdistrict5.org -- 5th District Aldermanic Website
> http://portev.org -- Electric Vehicles, Solar Power & More
> http://portgardenclub.org -- Port Washington Garden Club
> http://portlightstation.org -- Light Station Restoration
--
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>
> Lee Hart wrote:
> >> Under these conditions you have DC flowing in the motor windings.
>
> Rich Rudman wrote:
> > With DC in the windings you have a very good brake! It don't turn
> > very good!
>
> Exactly! The situation being discussed was a synchronous AC or brushless
> DC motor at stall (0 rpm), or an induction motor that is rotating
> backwards when you want it to go forwards (for which 0 rpm would be the
> "correct" way to produce torque in the opposite direction that it is
> rotating, i.e. brake it).
>
> > But you still need the voltage to push the amps. A 240 volt motor
> > seeing 100 amps is going to need quite a bit of volts to make this
> > happen, say 12 to 24 volts.
>
> Check the DC resistance of a large AC motor. It is VERY low! It *has* to
> be, or its efficiency would be terrible.
>
> For example, I just measured a 15 HP 240vac 3-phase motor at 0.12 ohms
> phase-phase. It would draw 100 amps at just 12vdc. And this is too small
> a motor for a traction drive. Victor can probably tell you the DC
> resistance of his Siemens traction motors, and I'll bet it is even lower
> than this.
>
Yea Lee I darn near painted my self into a corner on this one. I have a
3 Hp 230Vac, and the wires are tiny, like #10 or #12 gage.
100 amps sure won't flow through this very well. But yea yer right. The
bigger ones have pretty beefy wire. And for that starting torque of
10x, they need to move some pretty serious amps.
For
> > Six switches yes, but the low side switches can be locked full
> > on with NO switching losses. Just conduction. You don't have to
> > PWM both sides of the bridge. One is enough for current control.
>
> True, but the ones that *are* switching are having the problem I
> mentioned; not enough time to fully switch on/off due to the extremely
> low duty cycle, and thus very high switching losses.
>
That's not what I see on a state of the art IGBT. At 20Khz they
commutate very cleanly.
> >> Suppose you want to apply 100amps at 3v to the winding with a
> >> 300v battery pack. That takes a 3v/300v = 1% duty cycle. You want
> >> to switch at 15 KHz, so it is inaudible. The on-time is thus 1%
> >> of 1/15KHz = 0.66 microseconds. If you're using IGBTs, they can't
> >> turn on and off that fast.
>
> > This is where you are rather wrong. A power module now a days can
> > be run at 50 to 100Khz.
>
> This was just an example.
>
> Sure, MOSFETs can run faster; but who is using MOSFETs in an AC drive?
> Just about all of them use IGBTs. Give me the specs for a real IGBT
> module used in a real AC induction motor drive. Look at its turn-on,
> turn-off, and storage times.
Powerex CM200DU-12F
The NF switch even faster, and have better Rthetas, and slightly better
diodes
You can get 1000 volt Fets now, and easy 200 and 500 volt Fets.
The 500 volt Fets, now make about as much heat as 600 volt Igbts. You
CAN do 1Meg Pwm switching at 500 volts with Fets. This would enable
Damon at DCP to do 400 volt Mosfet controllers, and use his old gate
drive Vsat circuits, and live to tell about it. AKA A T-REX could come
back with Fets.
The PFC20s use APT80GP60 Igbts good for 150Khz, and 600 volts. I drive
them to 450 VDC and 40 Khz. I have not done limit stress tests on the GP
series, the predicessor, GT series had a switching loss limit in our
apps at 55 Khz. These deices have allowed the PFC20s to become PCF25
and 30s. In the buck enhanced PFC20s I am allowing 30 amps AVERAGE
current, and peaks may get to 2x at switch time. I am killing Caps now,
not Silicon. You can run Igs where fets ruled 10 years ago and Fets
where Igs ruled just months ago.
I intend to evaluate Fets in a PFC20 very soon. I have the samples.
Lee... using Fets in Ac drives??? anybody doing 200 volt work and below.
Also all the fork truck AC induction drives use them, and all the
integreated starter/alternator designs use them. Every BLDC drive that
is under 100 volts use them.
I expect that we will see some industrial drives with 240VAC mains use
Fets this season. Clearly PWM uses with a high switch rate will be the
folks that take advantage of the new SOA that we all want.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
What are you seeing that I am not???
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
>
> Rich Rudman wrote:
>
> > > Siemens drives have 0.7 Hz lowest frequency (spec is 0.7-400 Hz).
> > >
> >
> > Yea and that is a +- number they can go through 0 to reverse rotation
> > right??
>
> I don't know, it must be. Else I can't explain smooth transition.
>
> May be 0.7Hz is specified as lowest still producing rated torque
> (same as in flat const torque region). Below 0.7 Hz you don't get
> this torque (and don't really need) but it still generates
> any freq down to 0.
>
> Victor
A stator with zero rotational HZ, (DC buck mode) Will make the drive
into a negative torque state, with either positve OR negative rotation.
It's a Nice Brake either way.
The controller needs to drop through this state in a smooth reversal
command. I am sure the Siemans drives can do this.
The slowest a AC drive can go is kinda a moot point. How much torque it
can make at this point is not. Since at this point if you put the full
slip hz on it you will get full torque if you can put the full rated
amps on it at the same time. In some drives this results in shearing off
the output shaft!!!
My kinda torque!!
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Does anyone have any experience or information to share on LiPolymer batteries like
UltraLife's?
(http://www.ultralifebatteries.com)
They don't seem interested in the EV market even though their marketing material
implies that they might be down the road, but it certainly seems like their batteries
have some characteristics that would make them ideal for EV use...low weight, no
gassing, lack of memory effect.
The only thing that seems to suck is their capacity, which looks like their highest
rated is only 2.8Ah (3.8V) per cel - but it seems they could be connected in such a
way as to provide increased capacity. The 3V 2.8Ah cel weighs only 80g!
Cheers,
.Steve Coallier
"Attack life, it's going to kill you anyway!"
--- End Message ---
--- Begin Message ---
I agree, but isnt the problem with Lemco sized motors tied directly to
wheels is that they lack a torque range capable of accelerating a car
with any speed. Since a CVT is continuously variable you can keep the
electric motor at its highest power output level for an infinite
amount
of time by simply changing the gearing as you accelerate. When
cruising, simply change the gearing so that the motor is at the most
efficient point. Am I wrong?
No, the problem is that a single Lemco isn't powerful enough for
anything other than a motorcycle or very small (or very slow) car.
Wait - I have been talking about using two or four motor/controller/CVT
combinations, not one. And I'm not speaking of the older Lemcos, I
mean the new 2x2s that are producing 22kw
Adding a CVT will rob you of nearly half the Lemco's power making it
even less suitable.
Where did you come up with this statistic? CVTs are much better than
automatic transmissions due to the improvement/elimination of the
torque converter. You get much less slip. I don't mean pull a CVT
from a Honda Insight, but use a smaller - lighter duty one from an ATV.
You can ever get performance improvement kits, such as this:
http://www.atving.com/editor/review/accessory/hotseat/clutch.htm.
Even you are using the Lemco in a vehicle where it's not powerful
enough
for a single speed transmission, then use a manual multispeed
transmission. However you will STILL be limited by how much power it
can produce. A single Lemco-200 in a 3,000 lb EV will be fine as a
parking lot cruiser but will never make it to highway speed, regardless
of transmission.
Note that none of my initial discussion ever said one Lemco. It said
two, or four.
-Sam Harper
--- End Message ---
--- Begin Message ---
Well, I won't be joining [I don't do Yahoo groups], but if anyone sees any
messages appropriate to me, please send them my way.
----- Original Message -----
From: "Tom Hudson" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, June 15, 2003 1:51 PM
Subject: New Yahoo Group for Evercel Nichel-Zinc Batteries
> I went ahead and set up a Yahoo Group for discussion of Evercel NiZn
battery
> technology with an emphasis on EV applications. I belong to a similar
group
> for Saft NiCds and it's great for focusing on just that technology -- Not
a
> lot of traffic on that list but when a question comes up, people respond
> very quickly -- No "noise" from non-NiCd traffic. This is not a "snub" to
> the EV List, but a way for those of us looking at NiZn technology to have
a
> dedicated discussion area.
>
> Since the Evercel technology is relatively new, and some of us are working
> them into existing EVs I think this group will be a good way for all of us
> to share info, ideas and solve problems.
>
> To join the group, go to:
>
> http://groups.yahoo.com/group/Evercel-EV
>
> I hope to see you there.
>
> -Tom
>
> Thomas Hudson
> http://portdistrict5.org -- 5th District Aldermanic Website
> http://portev.org -- Electric Vehicles, Solar Power & More
> http://portgardenclub.org -- Port Washington Garden Club
> http://portlightstation.org -- Light Station Restoration
>
--- End Message ---
