EV Digest 5507
Topics covered in this issue include:
1) Re: g'bye Porsche
by "Mark Ward" <[EMAIL PROTECTED]>
2) RE: 200 miles highway range on flooded lead acid: Is it possible?
by "Bill Dennis" <[EMAIL PROTECTED]>
3) Re: Three-wheel Go-cart
by "Michael Perry" <[EMAIL PROTECTED]>
4) Re: 200 miles highway range on flooded lead acid: Is it possible?
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
5) Re: Regen-ask a Prius owner
by Cor van de Water <[EMAIL PROTECTED]>
6) Re: 200 miles highway range on flooded lead acid: Is it possible?
by "Michael Perry" <[EMAIL PROTECTED]>
7) Re: Aerodynamics .. viktor's idea .. to reduce 'drag' to near zero
by "peekay" <[EMAIL PROTECTED]>
8) Re: Fans in parallel .. or tesla vacua device in reverse .. to act as a
compressor or fan
by "peekay" <[EMAIL PROTECTED]>
9) Re: Source for NiFe batteries (Was: Question about NIMH patent(s))
by "Michaela Merz" <[EMAIL PROTECTED]>
10) Re: Regen-ask a Prius owner
by "Michael Perry" <[EMAIL PROTECTED]>
11) Re: 200 miles highway range on flooded lead acid: Is it possible?
by "John Westlund" <[EMAIL PROTECTED]>
12) Chevron
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
13) Re: Fans in parallel
by "Mike Phillips" <[EMAIL PROTECTED]>
14) Re: Fw: Vectrix - Now Belt verses Chain verses Shaft drive types
by [EMAIL PROTECTED]
15) Re: AC vs. DC
by "David Roden" <[EMAIL PROTECTED]>
16) Re: UK Electric Van on Ebay 4640056459
by "David Roden" <[EMAIL PROTECTED]>
17) PFC and the humming breaker
by "David Roden" <[EMAIL PROTECTED]>
--- Begin Message ---
I would have to agree about the path for current being necessary. The
battery by itself isn't going to do anything without a load on the string.
There has to be some other catastrophic failure of insulation or a device.
Of course this may never be known.
Maybe a Poltergeist?
Mark Ward
95 Saab 900SE "Saabrina"
www.saabrina.blogspot.com
----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 5:13 PM
Subject: RE: g'bye Porsche
michael bearden wrote:
I was way puzzled until Brian came over on Monday and said
that he had talked to Roderick (Wilde) who said he remembers
one other time this happened to an EV with Optimas (which I
had). One cell reversed, and turned into a very hungry
resistor/heat sink which caused the destruction of the EV.
This sounds like a possibility, but only if there was some path for
current to flow through the failed cell, and a source of voltage to
force the current to flow.
In a buddy-pair setup, the good battery will discharge into the its
lower voltage partner in the event that a cell fails shorted or
reversed.
In a setup with paralleled strings, the higher voltage string will
discharge into the lower voltage string should a cell fail shorted or
reversed in one string.
In a single string pack, there shouldn't be any source of voltage to
send current through the shorted/reversed cell unless the car is on
charge.
The only way that an internal battery failure could have resulted in
your fire is if an Optima somehow failed internally such that the
remaining cells in the battery were able to discharge through this
internal resistance and cause localised heating sufficient to ignite
some combustible materials; a simple shorted or reversed cell would not
do it.
I hesitate to say it, but another possibility is that the failure was
*external* to the batteries. You mention that you were using regs, and
that the fire appeared to have started near a couple of the weakest
batteries. Regs could provide a possible path through which a battery
could drive sufficient current to cause a fire if conditions were right.
If a battery/cell failed *open*, and there was some load connected
across the pack (dc/dc, or possibly even an inactive charger, depending
on its design) to provide a path for current to flow, then that
battery's reg would be subjected to full pack voltage, and if not
appropriately fused this could result in enough power dissipation in the
reg to start a fire. Regs also do not take well to exposure to the
elements, and your car was parked outside. It could be one of those
situations where the failure actually occurred during charge; something
got hot enough to start some flammable materials smoldering, but it
wasn't until hours later that things got fanned into full blaze...
It seems at least as likely as the failed cell theory, especially since
with your single string setup a cell failure should just have left you
with a pack voltage 2V or 4V lower than expected.
Cells failing shorted is certainly not unique to Optimas; it is a
possible failure mechanism for any lead acid battery, and for
cylindrical Li cells. I've never heard of a cell spontaneously
reversing, though cell reversal during discharge is certainly a
possibility for any lead acid battery.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I heard a segment on the radio yesterday that got me wondering. We usually
try to use small, light cars. But, instead, how about going the opposite
way and using something like one of those old Checker Cabs? Those things
had cavernous space inside. They even had a fold down third seat that you
could remove for extra battery space. Big, trunk and under-hood area too.
Yeah, they were heavy and probably not too aerodynamic, but you could fit
scads of PbA batteries in them.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tom Shay
Sent: Friday, May 19, 2006 2:02 PM
To: ev@listproc.sjsu.edu
Subject: Re: 200 miles highway range on flooded lead acid: Is it possible?
Yes, the Red Beastie concept could be improved on a little, but
should it be? I think Beastie was an interesting demonstration
of what can be accomplished by stuffing more batteries into a
pickup truck. It isn't a practical electric vehicle. As I recall, it
weighed 5300 lbs without occupants or payload. Of what use
is a pickup truck that is already 1000 lbs overloaded before
adding occupants or payload?
I wonder if anyone has built a copy of Beastie or if she's one of
a kind?
----- Original Message -----
From: "John Westlund" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 7:18 AM
Subject: 200 miles highway range on flooded lead acid: Is it possible?
> Most here are familiar with Dick Finley's "Red Beastie", a
> converted Toyota XTraCab that is loaded with 40 Trojan T105
> golf cart batteries and gets 120 miles highway range(At
> roughly 60 mph).
>
> But I think it is time to expand upon this concept. I don't
> feel the long range 'lead sled' concept has seen its full
> potential.
--- End Message ---
--- Begin Message ---
That's what I was working with, also. The C-lyte requires 48V.
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>; <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 7:52 PM
Subject: Re: Three-wheel Go-cart
> Hi-
> The battery weight has been increaced to 67lb.
> This will allow two 33lb. optima red tops.
> Check "Electathon America" web sight, lots of info there.
> F.T.
>
>
> > [Original Message]
> > From: Michael Perry <[EMAIL PROTECTED]>
> > To: <ev@listproc.sjsu.edu>
> > Date: 5/19/2006 4:57:48 PM
> > Subject: Re: Three-wheel Go-cart
> >
> > I'd like to hear more, Juergen. I was thinking of something similar w/
the
> > spare C-Lyte motor I had. My problem was voltage. They'd allow 2 batts,
> when
> > I was looking at the rigs, but that was several years ago. I was one of
> the
> > fairly early adopters of this motor and, despite lots of probs, did
manage
> > to get a bike assembled, albeit at a high cost.
> >
> > Which motor did you use? What range/speed did you get on your run? What
> > battery set?
> >
> > W/ the 400/500W motor, I manage to get about 25/20 out of the rig, on
800W
> > from the wall... somewhere around 850-1100MPG equivalency... w/o
pedaling.
> > That's on 4 "old/new" Hawker 13S.
> >
> > ----- Original Message -----
> > From: "Juergen Weichert" <[EMAIL PROTECTED]>
> > To: <ev@listproc.sjsu.edu>
> > Sent: Friday, May 19, 2006 7:07 AM
> > Subject: Re: Three-wheel Go-cart
> >
> >
> > > I used this configuration last year in my first ever Electrathon entry
> > > and came in third overall. I used a Crystalyte hub motor in the front
> > > wheel and it handled great. A weak battery pack (my fault) kept us
from
> > > winning speeds unfortunately. This year it will be different! ;-)
> > > J
> > >
> > > p.s. we had lots of juice left at the end of the run but not quite
> > > enough voltage during the run for top speeds due to two sagging
> > > batteries in the string - again my fault - didn't leave enough time
for
> > > testing prior to the event.
> >
>
>
--- End Message ---
--- Begin Message ---
John,
I like your forward thinking and I agree whole heartedly that
aerodynamics is a much under considered property. I've read threads
(elsewhere) that were bold enough to state that aerodynamics doesn't
matter in modern car design for speeds under 100mph ... I'd say this is
hog wash. I'd like to see these same individuals drive a refrigerator
box around with the open side facing forward if they don't think air
resistance isn't important.
I've been so intriqued here of late with aerodynamics (deja vu ... just
prior to your msg regarding Phil Knox ... excellent timing) that I've
been contemplating the following design:
http://faculty.washington.edu/jbs/itrans/roane.htm
http://www.tritrack.net/
... and combining it along with (some modifications) the following idea
of design:
http://www.rqriley.com/frp-foam.htm
There are a lot of design considerations; and I'm certain some would
argue why re-invent the wheel, but that's what we're all talking about
anyway. If there were a way to get a custom roll cage built that would
accommodated the front end of a modern car with air bags, where the
bodys' structural members were narrow something interesting might be
able to be created using the shape of the TriTrack.
With something like this in mind your constraints of:
a) 0-60 mph in 18 seconds or less
b) Top speed 90 mph or greater
c) 200 miles range or greater at 60 mph
d) Capability to seat 4 or more adults
e) Under $20,000 total cost, including donor chassis and shipping for
components
should be more than possible.
I like your proposal and it seems that you have been thorough in your
research. By chance do you have your donor yet? I don't have a Madza
B2000, but I do have an '83 Ford Ranger (a bit older and clunker) I'd
part with for $500 if your close by on the east coast. As you take
comment, keep in mind this is what experimentation is all about. You've
devised the first stages of the scientific methodology, now to test your
hypothesis (no one will really know till it's tried ... Einstein never
thought a sustained nuclear reaction would be realized, so who really
knows). God's speed and good luck with your ideas.
Ralph.
John Westlund wrote:
Most here are familiar with Dick Finley's "Red Beastie", a
converted Toyota XTraCab that is loaded with 40 Trojan T105
golf cart batteries and gets 120 miles highway range(At
roughly 60 mph).
But I think it is time to expand upon this concept. I don't
feel the long range 'lead sled' concept has seen its full
potential.
Why? Aerodynamics, aerodynamics, and again, aerodynamics.
Trucks have horrible aerodynamics. But it is possible to
change that.
In another topic I linked and mentioned an article
describing how Phil Knox improved his highway fuel economy
nearly 30% by building aerodynamic modifications to his
truck. I'll link it again:
http://www.evworld.com/view.cfm?section=article&storyid=870
Of all the long range 'lead sled' trucks built, none of them
have made such extensive use of aerodynamic modifications.
These conversions could benefit greatly from these
modifications insofar as range and top speed are concerned.
If it can result in a 30% fuel economy increase for a gas
truck, it can result in at least the same increase in range
for an electric truck. In the case of "Red Beastie", this is
an additional 40 miles range or more.
Many think advanced batteries are needed for an EV to
achieve range and performance comparable to the minimum
gasoline-powered car.
I say hogwash.
It is theoretically possible to get range comparable to an
IC passenger vehicle on lead acid batteries, given proper
attention to efficiency.
What would be interesting is if someone could build a lead
acid powered EV that could meet ALL of the following
constraints:
a) 0-60 mph in 18 seconds or less
b) Top speed 90 mph or greater
c) 200 miles range or greater at 60 mph
d) Capability to seat 4 or more adults
e) Under $20,000 total cost, including donor chassis and
shipping for components
The performance parameters above are basically what an IC
economy car could achieve in the late 1970s/early 1980s. It
may not be fast at all, even could be described as anemic,
but it is acceptable performance for keeping up with
traffic. Even the cruising range is there.
Is it possible to achieve these parameters using flooded
lead acid golf cart batteries? Without any advanced
batteries needed? I'm about to explore this possibility.
Demonstrating this sort of performance would make an
electric vehicle conversion practical and palatable to a
much larger percentage of the population.
The following setup will be simulated, with costs and weight
tallied and donor vehicle cost not included. Shipping is
assumed to cost 10% of all components marked with *.
-WarP 9'' series DC motor x1 160 pounds $1,575 (EV Source)*
-Trojan T145 flooded lead acid Golf Cart battery x40 2,840
pounds $5,140 (Trojan Battery)*
-Godzilla Controller(72-300V DC, 1,000 amp max, HEPI) x1 16
pounds $2,555 (EV Source)*
-PFC 20 Charger x1 20 pounds $1,525 (EV Source)*
-Vicor DC-DC converter (300Vmax, 12Vout, 200W) x1 8 pounds
$700 (Vicor)*
-E-Meter x1 $229 (Xantrex)*
-Solid-State Ceramic Heater Core x1 $75 (Grassroots EV)*
-Adaptor Plate x1 15 pounds $800*
-Miscallaneous components(Heat shrink tubing, fuses, steel
for battery racks, ect.) 150 pounds $1,500*
-Donor Vehicle 1980s Mazda B2000 pickup truck w/extended cab
2,600 pounds $1,000
-Sheet metal, plastic, fiberglass, and other components for
aerodynamic modifications 30 pounds $100
-Nokian 205/70R15 LRR tires x4 $268 (Nokian)*
-Leaf Springs x4 $300 (Renegade Hybrids)*
-Redline MTL synthetic transmission oil $15
-alignment correction to 0 camber, 0 toe is free with tire
replacement
Roughly 600 pounds of IC related components can be removed
from the donor. The donor has an estimated drag coefficient
of .45 and an estimated frontal area of 22 square feet. With
aerodynamic modifications, the drag coefficient is expected
to be reduced to .25. The donor vehicle cost was an
estimate. It is assumed normally 2 passengers will occupy
the vehicle, so 350 pounds will be added to account for 2
passengers and any other onboard items.
The Nokian NRT2 LRR 205/70R15 tires chosen have a .0085
rolling resistance coefficient. The specific model was
chosen for its ability to handle a 1,480 pound payload per
tire. This allows room for a gross vehicle weight of 5,920
pounds, or 681 pounds of passengers and luggage. These tires
are also rated to 118 mph. The tires are assumed to have no
weight change over stock tires. This is incorrect, but the
weight of the stock tires is unknown.
Total Cost: $17,249
Total Weight with two occupants and lugage: 5,589 pounds
Max Weight: 5,920 pounds
In order to maximize range, the following aerodynamic
modifications could be done with sheetmetal, plastic, and
fiberglass:
-aeroshell, a tapered bed cover made of fiberglass
-underbelly, made of corrugated plastic
-grille block, made of corrugated plastic
-rear wheel skirts, made of sheet metal
-front air dam, made of sheet metal
-side skirts, made of sheet metal
-rear diffuser, made of sheet metal
-wheel covers, made of corrugated plastic
-build shaved door handles from parts found in junkyard,
weld a sheetmetal backing plate to where the door handles
were
This would get the drag coefficient down to an estimated
25, similar to Phil Knox's pickup truck.
Further, the brakes can be adjusted so that they don't drag.
So the following truck will be modeled:
Weight: 5,589 pounds
Drag Coefficient: .25 (from aero mods)
Frontal Area: 22 square feet
Drivetrain efficiency: 93% (slight boost from synthetic oil)
Tires: 205/70R15, which means a tire diameter of 25.34
inches.
The Mazda B2000 pickup has the following gear ratios:
1- 3.622
2- 2.186
3- 1.419
4- 1
5- .858
F- 3.909
The batteries would be arranged in a single 240V string. The
Zilla would be configured to limit maximum current draw to
450 amps, maximum motor current to 1,000 amps, and maximum
motor potential to 170V. At 450 amps, the Trojan T105
batteries would sag to roughly 4.5V, allowing a maximum of
122 horsepower from the batteries. The 500A limit is imposed
to prevent battery damage.
Thus modeling the 9" motor, we get the following torque
versus speed curve and power versus speed curve under
maximum acceleration:
0 RPM 220 lb-ft 0 HP
1000 RPM 220 lb-ft 42 HP
1500 RPM 220 lb-ft 63 HP
1750 RPM 220 lb-ft 73 HP
2000 RPM 195 lb-ft 74 HP
2500 RPM 178 lb-ft 85 HP
3000 RPM 164 lb-ft 94 HP *peak motor horsepower, limited by
battery pack*
3500 RPM 132 lb-ft 88 HP
4000 RPM 105 lb-ft 80 HP
4500 RPM 83 lb-ft 71 HP
5000 RPM 69 lb-ft 66 HP
5500 RPM 55 lb-ft 58 HP
6000 RPM 44 lb-ft 50 HP
A motor redline of 6,000 RPM was chosen to prevent motor
damage. The batteries are the limiting factor in
acceleration and power that the motor can deliver. Stiffer
AGMs would extend the torque curve out more dramatically
improving acceleration but add greatly to the cost.
Now it is time to simulate acceleration and top speed. The
following acceleration calculator was chosen for its ease of
use and accessability:
http://www.nightrider.com/biketech/accel_sim.htm
The proper gear ratios, torque versus RPM, weight, drag
coefficient, and tire rolling resistance parameters were
input. A drivetrain loss was estimated at 7%, which would
account for a slight efficiency boost from synthetic
transmission oil. It is estimated the front/rear weight
distribution will entail 70% rear, 30% front due to the bed
being loaded with batteries, and wheelbase was estimated at
110 inches. In order to prevent the program from committing
an error, a launch RPM of 100 was chosen.
The optimum shift points for maximum acceleration were 3,920
rpm for 1st to 2nd gear, 3,810 rpm for 2nd to 3rd gear,
3,650 rpm for 3rd to 4th gear, and 3,300 rpm for 4th to 5th
gear. A shift duration of ½ second was assumed.
We get the following estimations:
0-30 mph acceleration: 4.6 seconds
0-50 mph: 12.7 seconds
0-60 mph: 17.7 seconds
Top speed: 111 mph
1/8 mile drag race: 12.7 seconds @ 50 mph
¼ mile drag race: 20.5 seconds @ 64 mph
This meets the specified performance parameters. It's about
as fast as a typical gasoline powered car from 0-30 mph, and
from 0-60 mph, about as fast as an 80s model pickup truck
with an anemic 4 cylinder engine. It wouldn't be fast, but
it would be able to safely merge with traffic. An added perk
from the Zilla is that it would easily smoke its tires and
pull tree stumps.
For range, a simulation is going to be performed with Uve's
Calculator. The above parameters will be entered, along with
a brake/steering drag coefficient of .002 to account for
corrected alignment and machined brakes. A relative wind
factor of 1.2 was chosen to represent an aerodynamic
vehicle, and a wind speed of 7 mph was chosen to represent
outside wind conditions in average weather.
http://www.geocities.com/hempev/EVCalculator.html
The following results were obtained:
Range at 50 mph was 377 miles in 3rd gear.
Range at 60 mph was 216 miles in 3rd gear.
Range at 70 mph was 162 miles in 4rd gear.
And just for curiosity's sake, range at 90 mph was
calculated at 102 miles in 4th gear.
This is within the constraints outlined above.
In theory, such a vehicle is possible. In practice, no one
has tried it. The closest to it are John Wayland's "Red
Beastie" and Brian Methany's "Polar Bear", two trucks
that have achieved 120 miles highway range on similarly
large battery packs. Neither truck has extended cab, so they
could only seat 2 or 3 adults.
This truck I outlined would be a passenger vehicle capable
of seating 4 adults, accelerating from 0-60 mph in under
17.8 seconds, topping out at 111 mph, and doing 200 miles
per charge at 60 mph. This would require the proper
efficiency modifications to achieve this range and top
speed. Without the efficiency modifications, range and top
speed would be comparable to the two conversions referenced
above.
Such a vehicle as I outlined would not only be beneficial in
demonstrating that advanced batteries are not needed for a
conversion to compete with gasoline powered cars in range
and top speed, but it would also serve as a viable platform
for a conversion business to harvest ideas from.
If the $17,000 component price is too high, performance
could be sacrificed for a significant cost reduction. A
lower voltage setup with two battery strings in parallel, a
cheaper charger and controller, and less luxuries such as
heating could result in a conversion with similar range and
a price tag around $8,000. But 0-60 acceleration would
increase to around 40 seconds with a 120V, 400A Curtis
controller and the batteries split in 2 parallel strings.
For a few thousand dollars greater than the projected $17k
concept, AGMs and regs could be put in place of the flooded
batteries, allowing performance comparable to the new cars
of today. But this would bring costs near $20,000. A Zilla
2k would add even greater costs, but allow rapid
acceleration.
A custom built midsize or luxury car based on a pickup truck
chassis would have similar carrying capacity, increased
passenger and cargo room, but also significantly less weight
and frontal area compared with the fully outlined conversion
concept of the Mazda B2000. Purpose built as an EV, the same
battery pack could be fit into the car concept. This reduced
weight and frontal area would result in dramatically
increased acceleration and increased range provided the same
attention is paid to efficiency. Perhaps in a purpose built
car with this setup, a 0-60 acceleration time of 14
seconds(comparable to a 1st generation Toyota Prius) a range
of 250 miles at 60 mph, 200 miles at 70 mph, and top speed
in excess of 120 mph could be achieved. No advanced
batteries needed.
So, what do you think of this idea? Criticisms? Suggestions?
If I had the cash, I'd attempt this truck!
Is it a feasible concept?
Dick Finley pushed the envelop with his pickup. Were he
alive today, I'm sure he would keep pushing it more. This
concept appears to expand upon his final conversion in a big
way.
--- End Message ---
--- Begin Message ---
Hi Michael,
Interesting - you gave the missing data yourself:
The Prius goes a mile on 200wHs of juice, this is probably not a
measured value but all smaller EV sedans will have somewhere
between 150 and 200 Wh per mile figures, a truck will typically
need 250 to 300 Wh per mile (or more).
So if you take the data of the leaves (400 - 600 Wh) and
divide by 200 Wh/mi then you get 2 - 3 miles for the Prius.
Since 2 to 3 miles is 1/6 to 1/4 of the total distance driven,
the average is assumed: about 1/5 or 20%.
If you take 5 times as much energy (2000 to 3000 Wh) then you
should be able to propel the Prius for 12 miles if you can feed
its electric motor this battery power.
Again, its not exact math - in stop & go traffic the Prius may
need more power than this, but the figures are consistent with
the power measured by other EV'ers for sedan EVs.
Since the terrain for this test is not specified, I have seen
other assumptions/estimations from the Prius screen that came
out much lower. I like to coast to a traffic light, so I typically
have very little regenerated power.
Therefor the last line reads YMMV.
Hope this clarifies,
Cor.
Michael Perry wrote:
Please, what am I missing? I'm not trying to be sarcastic... this is a
serious question.
The post says "Each leaf represents 50wh so that makes 400 to 600 wHs of
regen. That's about 2 to 3 miles. Right around 20%."
I'm trying to relate how 3 miles of extended range is shown by regen... or
20% regen rate given back? I know the Prius' little gauge and have seen it
in operation. I'm trying to see how that relates to the real world and how
that extrapolates into 2 to 3 miles of range.
----- Original Message -----
From: "Cor van de Water" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 6:54 PM
Subject: RE: Regen-ask a Prius owner
> Michael,
>
> Please read the message below carefully,
> especially the translation from the Prius display to WattHours.
>
> Regards,
>
> Michael Perry wrote:
> I've been following your posts on Regen. Please elaborate. If you can go a
> mile on 200wHs of juice, then you are getting around 100MPG?
>
> I'm not following. How do you know that that represents 20% of your power
> back through regen?
>
> ----- Original Message -----
> From: "Chet Fields" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Friday, May 19, 2006 6:57 AM
> Subject: RE: Regen-ask a Prius owner
>
> > Why didn't I think of that! I have a Prius and on a typical
> > 12 mile commute I get about 8 to 12 'little green leaves'.
> > Each leaf represents 50wh so that makes 400 to 600 wHs of regen.
> > That's about 2 to 3 miles. Right around 20%.
> >
> > YMMV
--- End Message ---
--- Begin Message ---
Well said... and part of why NEVs go so far on so few batts. At below 30MPH,
rolling and wind resistance have little effect on vehicles. In a limited
fashion, I see this with my toys. My e-bike gets much better range at below
20, than at 25MPH, though the motor comes into it's peak performance at the
higher range.
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 8:36 PM
Subject: Re: 200 miles highway range on flooded lead acid: Is it possible?
> I like your forward thinking and I agree whole heartedly that
> aerodynamics is a much under considered property. I've read threads
--- End Message ---
--- Begin Message ---
in the company of experienced experts, it is not with great confidence that
one can suggest .. yet .. may i ?
the drag is caused by the air molecules sticking to the surface of cars,
planes, etc ..
viktor schauberger patented an idea to reduce drag to near zero .. which is
absurdly simple .. but works for a different application ..
maybe an adaptation of that "theory" would see wierd rhombic thingys all
over the car front, to make the air flow "away" from the surfaces
..peekay
----- Original Message -----
From: "Lock Hughes" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Saturday, May 20, 2006 2:37 AM
Subject: RE: Aerodynamics
> EVen though my Currie scooter struggles to reach 20kmh on a good day, I
> regularly see 40+kmh air as headwinds...
> So I am still interested in aero re a "next gen" scooter, even at these
> slower speeds!
> Tks
> Lock
> Toronto
>
>
> --- Don Cameron <[EMAIL PROTECTED]> wrote:
> > If the car isn't driven much over 50kmh (30mph) aero improvements
> > probably won't make much difference.
> > Don
> > Don Cameron, Victoria, BC, Canada
> >
> > see the New Beetle EV project www.cameronsoftware.com/ev
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> > On
> > Behalf Of Mike Phillips
> > Sent: May 19, 2006 8:26 AM
> > To: ev@listproc.sjsu.edu
> > Subject: Aerodynamics
> >
> > I'm sure every little bit helps. But what I think would tell me just
> > how
> > much aero resistance is costing, is to put a vehicle on a chassis
> > dyno and
> > use the onboard Emeter to see what the WH/mile is without wind as a
> > factor.
> > Then drive it on the road at the same speed. The difference would be
> > mostly
> > due to aero resistance. Then do the same thing with aero
> > "improvements".
> > This may generate more facts than lore
> > ;)
> >
> > Mike
>
>
> __________________________________________________
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--- Begin Message ---
venturing to suggest .. as before .. may i ?
tesla patented a device called vacua .. which is very highly
effective for creating vacuum .. run in reverse, it can work
as a very effective compressor or fan .. it is absurdly simple !
..peekay
----- Original Message -----
From: "Mike Phillips" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 10:34 PM
Subject: Fans in parallel
> So if 5 fans of 30cfm each are in aerodynamic parallel, so they add up
> to 150 cfm total? In other words, if 5 fans were connected to the same
> box, can they push 150 cfm thru it? I bet not, but wanted to see if
> someone has been there and done that.
>
> Mike
>
>
>
> Here's to the crazy ones.
> The misfits.
> The rebels.
> The troublemakers.
> The round pegs in the square holes.
> The ones who see things differently
> The ones that change the world!!
>
> www.RotorDesign.com
>
>
>
> --
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--- Begin Message ---
So - let's say I would put 12 x 12V in my truck. Gives me 144 V nominal
for about 6500 $ and 220 Ah @ 20hrs rate. Weight would be 1600 pounds,
same as for T-125s. My question would be, if there is a high discharge
penalty like we have with LA - the more you draw, the less you'll get ;)
I may just be to stupid to understand the datasheet ....
Michaela
>>Has anybody looked at how much current could be drawn?
>
> Looking at the one hour discharge rate with the voltage dipping below
> 1 V immediately, you could go by the AH rating of the battery to
> determine the max. So the 220 AH battery would have a max draw of
> about 220 A. Very interesting battery I think considering the life
> cycles and cost per mile. If a dual battery arrangement were used,
> AGMs for acceleration, and NiFE for cruising, it could make for decent
> performance and low cost/mile. Assuming one can work out the logistics
> of a dual battery system...
>
> The 220 AH cells would make for a heavy car, but 144 V of 150 AH NiFE
> + 144 V of Orbitals might make an interesting combo and weight
> tolerable. They do say in their FAQ that capacities down to 20 AH are
> available, presumably special order.
>
> The NiFE datasheet:
> http://www.beutilityfree.com/batteryNiFe/battery_flyer.pdf
>
> Brad Baylor
>
--- End Message ---
--- Begin Message ---
OK... 200wHr w/ the engine running, per mile, right? I seem to recall a
post, just a couple hours ago, saying the EV1 took 8 times that amount to
travel at 60. The return seems a bit high to me, but since you are pulling
down around 70MPG, it's your dream to live.
I was also stumped by the 20% regen recovery. I would assume this is 20% of
the forward momentum? If it's 20% of the power to reach your destination,
then perhaps this is in town where it's all stop/go? Sort of like the
commercial where they guy is impressing his wife?
----- Original Message -----
From: "Cor van de Water" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 19, 2006 8:55 PM
Subject: Re: Regen-ask a Prius owner
> Hi Michael,
>
> Interesting - you gave the missing data yourself:
> The Prius goes a mile on 200wHs of juice, this is probably not a
> measured value but all smaller EV sedans will have somewhere
> between 150 and 200 Wh per mile figures, a truck will typically
> need 250 to 300 Wh per mile (or more).
> So if you take the data of the leaves (400 - 600 Wh) and
> divide by 200 Wh/mi then you get 2 - 3 miles for the Prius.
--- End Message ---
--- Begin Message ---
chemcat9 wrote:
>I like your proposal and it seems that you have been
>thorough in your research.
I wouldn't exactly call it thorough, but it seems to come
from the school of "that sounds about right".
>By chance do you have your donor yet?
Yes. I'm not doing a slow truck for my first conversion, but
a high performance sports car.
You can read about my plans for it here:
http://www.austinev.org/evalbum/630
Of course, given my budget constraints, it's not going to
start that way. I'm starting with as cheap a motor as I can
find, a contactor controller, homemade charger, and 72-96V
of flooded batteries. I'll keep upgrading as I obtain the
necessary money. Eventually, it will be where I want it: 25
Optima YT batteries, Zilla 1k, 9" motor, PFC charger, regs,
and a shitload of aerodynamic modifications. In theory, I
would be able to get 100 miles range from that setup to full
discharge. In practice, we'll see. There's a lot of big
"if's", most importantly how much I will really be able to
minimize the drag of this car. In reality, I might only get
30-40 miles, and I'd be happy with that. But I'm aiming much
higher.
--- End Message ---
--- Begin Message ---
More information on Chevron and its suppression of the building of
large Nickle Metal Hydride batteries.
http://www.evworld.com/blogs/index.cfm?page=blogentry&authorid=12&blogid=83
<http://www.evworld.com/blogs/index.cfm?page=blogentry&authorid=12&blogid=83>
--
Daniel Rivest
--- End Message ---
--- Begin Message ---
The blowers I'll be using are for Prius packs. So there is some
substantial airflow resistance.
Mike
--- In [EMAIL PROTECTED], "Mark Ward" <[EMAIL PROTECTED]> wrote:
>
> Hi Mike,
>
> Not sure what you are trying to cool, but a couple of suggestions
from my
> research.
> I have two Plymouth Neon 12" fans that put out HUGE amounts of air with
> about 4 amps. Plan to use one of them for my AC condenser as
opposed to the
> one the Saab had originally that was fused at 30 amps. I don't even
want to
> try and reconnect that one. I plan on using that for the AC, the
> transmission and Zilla coolers. The neon fans will take your hat
off! Got
> mine free of a junker. Additionally the Neon fans are multi-speed
and the
> control relay is on the frame.
>
> As a traction motor fan I have chosen in a BILGE fan easy to find on
ebay
> and plan to install that in the original path of the air intake
using the
> original filter box and hoses from the ICE. Bilge fans do about 250
CFM and
> are available in 3 and 4 inch sizes. (3 inch will match my hose
perfectly)
> These again use low current. Around $20 in price, produce very low
noise
> level and cosmetically pleasing to look at vs the ugly squirel cage
blowers
> offered by some EV outlets.
>
> Just my 3 cents worth
>
> Mark Ward
> 95 Saab 900SE "Saabrina"
> www.saabrina.blogspot.com
>
>
> ----- Original Message -----
> From: "Mike Phillips" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Friday, May 19, 2006 12:04 PM
> Subject: Fans in parallel
>
>
> > So if 5 fans of 30cfm each are in aerodynamic parallel, so they add up
> > to 150 cfm total? In other words, if 5 fans were connected to the same
> > box, can they push 150 cfm thru it? I bet not, but wanted to see if
> > someone has been there and done that.
> >
> > Mike
> >
> >
> >
> > Here's to the crazy ones.
> > The misfits.
> > The rebels.
> > The troublemakers.
> > The round pegs in the square holes.
> > The ones who see things differently
> > The ones that change the world!!
> >
> > www.RotorDesign.com
> >
>
--- End Message ---
--- Begin Message ---
I have two follow on thoughts....
First to mperry regarding the noise of a belt. How wide was the noisy belt
in your car? I was speaking about a fairly narrow belt say 3/4 inch. I am told
that a wide belt is noisy as air get trapped between the belt and the
pulleys. This is typically addressed by drilling holes that allow the air to
escape. Perhaps a shaft and belt drive are similar in terms of the noise they
generate.
Second to the efficiency issue. Would a tensioner that provides a fairly
constant pressure help the efficiency of a belt drive? Does anyone have
experience to share?
Mike Bachand
DEVC
Colorado
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--- Begin Message ---
Ah, nothing like a good old fashioned DC vs AC flame war! ;-)
Several posts, notably Lee Hart's, have summed up the overall difference
nicely. I'm not going to go near the technical differences nor will I weigh
in on the dispute between Otmar and Victor.
The following is a user's perspective on the matter. It's my 100% personal
opinion, having owned and driven both types. It's limited to the systems I
have experience with : Prestolite and ADC motors, Curtis controllers; and
Brusa medium-voltage AC drives. I say it's from a user's perspective, since
although I work on EVs, I do so because I have to and would give it up
gladly if I could buy a good OEM one that suited my needs.
Acceleration: IMO there is a significant difference between the driving feel
of a series DC motor with a typical on-road controller, and that of an AC
induction motor with a matched inverter. The induction motor seems to have
a smoother torque curve, which IMO improves driveability. The series motor
system feels - forgive me here - somewhat cruder. Others may not agree with
this, or may not care, so YMMV.
Regen: Regenerative braking, IMO, is also mostly a driveability issue. Most
neophyte EV owners are used to having at least a little engine drag in an
ICE car. When they release the accelerator in a series motor EV and the car
doesn't slow down, it causes a moment of "heart-in-mouth" disease. If you
get used to driving an EV with regen, you'll have the same reaction when you
drive one without. I realize that this is something one gets used to, and
most of us are savvy about such things, but IMO it's still a driveability
issue. Again, YMMV.
Regen certainly does extend range. How much depends on where you live; if
it's flat, the answer is "not much," but it can be significant (5 - 20%) in
a hilly area. This can make the difference between not quite enough range
and just enough.
If you want to coast instead (which can be more efficient use of momentum),
most AC systems allow you to either hold the neutral position of the
accelerator or shut off the regen.
It's usually impractical to do regenerative braking with a series DC motor.
OTOH, almost all AC systems provide it.
Safety: It could be said that there is more inherent safety in an AC system
because it is less likely to fail full-on, a typical failure mode with DC
systems. The practical consequence is that DC systems require extra
redundant failsafe shutdown systems to ensure that there is a way to remove
power should the controller unexpectedly apply full battery voltage and
current to the motor. In the best case this is done automatically. A big
red STOP button is darn good to have, but there is still the chance that one
may mash it 200ms after hitting the car (or kid) in front of him. What's
more, IMO, too many hobbyist EVers don't even have that much. Many home
builders simply don't provide enough protection against uncontrolled
acceleration in DC EVs. (I can say that because I've been guilty of being
similarly careless. ;-)
Parenthetically, IMO a DC EV should have at least three means of shutdown.
One main contactor should open when the accelerator is released, another
when the power switch or key is opened. The main breaker should be
accessable from the driver's seat. A fourth disconnecting means, such as a
mechanical shutdown (the Big Red Button), will improve the safety further.
(End of parenthetical DC safety lecture.)
Go power: It does appear that you get more raw torque per dollar with a
series DC motor and controller. In my view, this matters if you are racing,
but not so much for a daily driver. Those who like the excitement of neck-
snapping, tire-squealing acceleration may disagree with me. I got that out
of my system years ago. No slight intended; perhaps I'm just old before my
time. I freely admit that I drive like your grandpa. ;-)
BTW, regen comes more naturally to separately excited DC motors than to
series DC motors. But for some reason road EV sep-ex systems are not widely
available nor is the motor type very popular with EV hobbyists. Too bad;
sep-ex is a useful compromise, IMO.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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On 13 May 2006 at 14:53, John Luck Home wrote:
> My electric Van now listed on ebay in the UK
>
> item 4640056459
Looks nice!
Those Yuasa batteries are supposed to last 10 years? Do you really think
they will? What can you tell us about them?
Thanks,
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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Bob Rice stopped by here a couple of days ago, on his way back from Joliet.
He arrived with a hungry 120 volt Rabbit, so I hacked up a quick adapter for
him to plug in to the 240v 20a receptacle in my garage. Then we went inside
and watched his raw video footage for a while.
A few hours later, I went down in the cellar for something, and noticed that
my main electrical panel was humming quite loudly. The hum was coming from
the 100 amp main breaker (it's a Square D QO type). Both it and the 50 amp
QO breaker that feeds my garage subpanel were noticeably warm, though not at
all hot.
Bob has a 120v pack and a PFC-30 in the Rabbit. Although I didn't check it,
presumably the PFC was shoving 30 amps into the pack. (Right?) If the
PFC's efficiency claims are true, and I have no reason to doubt them, it
should have been drawing only a little over 15 amps from my 240 volt
receptacle. So why were the breakers getting warm? And why did the main
breaker hum so loudly?
I've never seen (heard) that effect with any other similar load. Not even
with my 240v Brusa switchmode charger, nor with my 120v K&W BC-20 glorified
triac light dimmer charger with its truly awful power factor. What's the
deal here? Anyone have an idea?
Thanks for the thoughts.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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