EV Digest 4484
Topics covered in this issue include:
1) Re: Dual Motors and Single Transmissions
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
2) Re: Crash safety and micro EV's
by John Wayland <[EMAIL PROTECTED]>
3) Re: Venturi Fetish video
by john bart <[EMAIL PROTECTED]>
4) Re: Engine Generator Question
by "Doug Hartley" <[EMAIL PROTECTED]>
5) RE: OT: Another idea that probably won't work
by Jeff Shanab <[EMAIL PROTECTED]>
6) Re: Venturi Fetish video
by Ryan Stotts <[EMAIL PROTECTED]>
7) Re: SAFT NiMH charging
by Ben Apollonio <[EMAIL PROTECTED]>
8) Please critique adapter
by David Dymaxion <[EMAIL PROTECTED]>
9) Re: Thermal runaway (was: RE: Another PFC Caution?)
by "Rich Rudman" <[EMAIL PROTECTED]>
10) Re: Pollution in small engines, Re: Rules of thumb for engine,
Generator Eff ...
by "Peter VanDerWal" <[EMAIL PROTECTED]>
11) 20 yr old 9" DC motor
by Marvin Campbell <[EMAIL PROTECTED]>
12) Re: I'm getting closer! (found a donor car) Comments?
by "STEVE CLUNN" <[EMAIL PROTECTED]>
13) Re: State of Charge calculations
by "Philip Marino" <[EMAIL PROTECTED]>
14) Re: Dual Motors and Single Transmissions
by "STEVE CLUNN" <[EMAIL PROTECTED]>
15) Re: EV smart car
by "Mark Hanson" <[EMAIL PROTECTED]>
16) Re: Please critique adapter
by "Roland Wiench" <[EMAIL PROTECTED]>
17) RE: Please critique adapter
by "Philip Marino" <[EMAIL PROTECTED]>
18) Re: State of Charge calculations
by Eric Poulsen <[EMAIL PROTECTED]>
19) Re: State of Charge calculations
by Evan Tuer <[EMAIL PROTECTED]>
20) Re: 20 yr old 9" DC motor
by brian baumel <[EMAIL PROTECTED]>
21) Re: State of Charge calculations
by "Philip Marino" <[EMAIL PROTECTED]>
--- Begin Message ---
Otmar, John Wayland, BadFish and others have used dual motors. Otmar uses a
tranny and leaves it in third I think. Wayland has two motors stright to
the differential. Dual ETEKs are somewhat common & mostly driven with two
sprockets. I even have Gemini. It's the two Motor/Controller scooter.
That just has two stock sprockets. I haven't had problems but I can climb
most any hill and I weigh 260. Lawrence Rhodes.....
----- Original Message -----
From: "justin vandeusen" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, July 06, 2005 9:32 AM
Subject: Dual Motors and Single Transmissions
Hello EV'ers!
Finally got back to list and have been enjoying
reading the posts that I missed while I was away. This
leads me to a question I have thought about alot
during that time: Has anyone used a dual motor single
transmission setup? If so:
1. How difficult was it to setup?
2. Are there more problems with mechanical wear and
tear with a dual setup?
3. Is this a common technology on EVs and hybrids?
Any information regarding this subject would be
greatly appreciated! Thanks your time!
____________________________________________________
Sell on Yahoo! Auctions - no fees. Bid on great items.
http://auctions.yahoo.com/
--- End Message ---
--- Begin Message ---
Hello To All,
Ryan Stotts wrote:
> Stu or Jan wrote:
>
> > Should small or micro EV's be built on a roll cage chassis for safety?
> > Has anyone made one?
>
> The Tango is built like that:
>
> "Because safety is such a concern for small cars in particular, we
> have designed the Tango around a roll cage that meets or exceeds both
> SCCA and NHRA regulations."
>
Boy, is that true! I had to somehow, find a way to fit a largish car stereo amp
in Tango.
I ended up suspending it from the front section of the roll cage...it's very
beefy! The
Tango is the car I'd rather be in, if I 'had' to be in a bad accident. Those
giant SUVs
out there would be in for quite a surprise if one of them tangled with the
Tango! With its
mass of batteries in the floor giving it surprisingly heavy weight for such a
narrow small
car, imagine the look one a Chevy Suburban driver's face as he get's out of his
demolished
land barge after running into the tankish Tango! Hopefully, with its rarity
status of
being a limited production hand-built machine, we won't be hearing of how well
the car
held up in an accident.
Kudos to Rick and Bryan for the thoughtful safety design.
See Ya......John Wayland
--- End Message ---
--- Begin Message ---
This file doesn't seem to be working. I downloaded the one bit torrent program
on the link and it doesn't seem to be working. Under "Tracker Status" it
keeps saying "Connecting Tracker to say Start, waiting for response". Is
anyone else getting this error?
Ryan Stotts <[EMAIL PROTECTED]> wrote:Towards the end of this program (at 18:49
minutes into it):
http://www.mininova.org/tor/46195
Amazing how quiet Ev's are after being around gas and diesel powered
vehicles for so long..
Video is very clear full screen. No need to watch it in a 4" square window.
__________________________________________________
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Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Hi Jerry and others interested in range extender generators,
I have found the Robin Subaru EX series engines, such as the EX-21 7 HP to
be ideal for this purpose and a good value for lightweight generators up to
9HP. These are steel timing chain driven OHC engines, rather like small
motorcycle engines in that aspect. They are designed to fight for market
share against the better known Honda GX series, by offering better quality
and performance, better cooling and lubrication, lower cost, lower emissions
and lower fuel consumption. They are "drop-in replacements" for the Honda
GX models, but typically offer a little more power in each case (e.g. the
7HP EX-21 at 35.3 pounds replaces a 6.5HP GX200 at 36 pounds) and have a
higher RPM rating as you would expect. I have a brochure which is 8 pages
just comparing the Robin EX with the Honda GX and showing the improvements
of their newer design, pictures of parts in each, etc. There are lots of
nice touches, like a fuel strainer in the gas tank filler. Many of the
things you might like to do or wish for, to improve a standard industrial
engine are already done.
Best Regards,
Doug
----- Original Message -----
From: "jerry dycus" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, July 06, 2005 10:47 PM
Subject: Engine Generator Question
snip
I'm open to an industrial engine though it would
have to be modified to lower emissions and some power
increase that would result from making it more eff as
a bonus. In fact probably what I'll do as I need new
units for this. The MC was for others who could use
used motors.
snip
--- End Message ---
--- Begin Message ---
I am not sure this is really off topic, we all must contend with the
best way to do the occasional 240 mile trip. My personal last impediment
to totally replace my ICE would be my typical 120 mile ending in a climb
of 2000-3000 feet (moms house), or 180 miles at 75mph also climb 2/3
way( alemeda or sf EV club meeting), 140 miles at 75 again with climb
in later half of trip(Sun Users group) Living in a valley pattern.
The other 362 days a year I go about 24 miles a day and can charge at work.
I think this is a great idea and will have the least waste for
combustion, I have wondered about it for years.
I would use rings and reverse flows to help cool the magnet area, if it
gets hot the magnets go by-by.
I remember seeing a build it yourself bounce engine that ran on
acetelene and used water in the exhaust to create thrust for a go-cart
in a popular mechanics magazine years ago. The details of construction
were there, it was a 2 cycle engine bouncing off the compression of the
gas using glow plugs and natural asperation, but I can remember how they
started it.
I wonder how different eff would this really be from a flat opposed 2
cyl with a simple flywheel that brings out the power to a rotary gen head?
Heat is the effiency bullshit detector and the exhaust is hot :-( a
lot hotter than the bearings from the reciprical to rotary conversion
So perhaps bring it out to a shaft and let the heated exhaust drive
steam generator to a multistage turbine on the same output shaft.
Co-generation generator :-)
Anyone; what is the best way to convert heat to electricity, could we
bolt something on to our dino-burners to put that heat to good work?
(after the cat of course)
This also reminds me of a discussion I started about shock absorbers.
How much energy is there in driving down a bumpy road? Imagine
chargeing your aux battery with power generated in an active suspension
system that is dampening the spring oscillations. The way the honda uses
it's motor to dampen engine vibratios. The shock would be a rare earth
magnet piston in a multilayer 3 phase winding body. It could be also
used the other way to activly push the wheel down faster than the spring
rate when going over a bump, this allows softer springs for a better
ride while also allowing better wheel control at higher speeds.
--- End Message ---
--- Begin Message ---
More then likely, if you have a hardware firewall(router), or are
running a software firewall, the ports that program uses are being
blocked.
Here is a link to the original, simple, bare bones client:
http://www.bittorrent.com/
You can configure the ports in it.
Two other programs:
http://www.bittornado.com/
http://azureus.sourceforge.net/ (Java program)
--- End Message ---
--- Begin Message ---
I don't know about Saft, specifically, but I can tell you that NiMH in
general is constant-current. It must be regulated & monitored
carefully -- at the end of charge (fast charge, anyway), the voltage
will peak, then actually drop 20mV/cell. Charge termination is
triggered when that voltage drop is detected. After termination of
charge, a small trickle charge is applied until the pack reaches 1.5V
per cell, or until a set time limit (90 minutes, I think?) is reached,
whichever comes first. If you can find a Saft specsheet, it should
tell you what charge & trickle currents to use.
If the pack nominal voltage is 336, can I safely
charge at, say, 1 Amp up to 340 Volts ? Even with no
individual cell monitoring ?
I would say that if your pack is more or less in balance, that's more
than safe, assuming you have large capacity cells. If I remember
correctly, trickle charge is something on the order of C/40, so if you
have 40Ah cells (or larger), then yes, 1A is plenty safe enough. NiMH,
like NiCd, is nominally 1.2V/cell, so chances are that, by the time
you're done fast charging, you'll already be above 340V. If you plan
on doing 1A the whole way, 340V is certainly safe, but it's quite low
and probably won't offer you much (if any) usable charge. Open circuit
voltage for a charged cell is typically around 1.3V.
In small numbers it's safe to charge NiMH in series -- it happens a lot
in consumer electronics -- but I don't know what happens in a large
string of large cells. I'm pretty sure you wouldn't need to monitor
every individual cell, probably just every 10 or so. The Ovonics packs
were 11 cells in series (designed to match a typical 12V battery),
although I'm not sure exactly how those were monitored.
Hope this helps!
-Ben
--- End Message ---
--- Begin Message ---
Here's my basic idea: Use steel and weld.
More details: 3/8 inch steel (thick enough or too thick?)
Bend a steel sheet into a circle and weld (i.e. make a short steel
pipe), to use as a spacer.
Rough cut an undersized hole in the tranny plate.
Weld the pipe/spacer to the tranny plate.
Machine the edge of the pipe/spacer to the right dimensions to match
the "magic number" flywheel surface to tranny mounting surface.
Machine a 4 inch centering hole and motor bolt holes in motor plate.
Weld the motor plate to the pipe/spacer.
Center the unit on a rotary table on a milling machine, using the 4
inch hole, and machine the tranny plate hole and bolt holes. Weld on
an oversized centering ring, and machine to size. The Porsche centers
the motor with the tranny via a male centering ring on the motor.
Centering on the 4 inch hole and machining the centering ring should
make these two concentric.
Any major oops in there? The benefits are that steel is much cheaper
than aluminum, fewer bolts, and smaller, and hopefully a bit lighter,
than most adapter designs.
One more crucial detail: The porsche tranny is held up at one end, is
bolted directly to the motor, and the motor is help up at the other
end. The motor+tranny assembly tries to rotate about the axles. With
torque multiplication up to about 4500 ft-lbs of torque (drag race
setup with drag tires and a heavy car) goes through the axles. So the
adapter doesn't just resist motor torque, it also has to hold the
motor and tranny together against the axle torque.
Thanks!
__________________________________________________
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Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, July 06, 2005 8:03 PM
Subject: Re: Thermal runaway (was: RE: Another PFC Caution?)
>
> >
> > > I did some surfing last night to try to understand the mechanics of
> >thermal
> > > runaway. I didn't have much luck. I get the basics - batteries heat
up,
> > > resistance drops, current rises, batteries heat up more, repeat until
> > > meltdown.
> > >
> > > Question 1: What I couldn't find any info on is how the charger
affects
> >the
> > > cycle. If you're in runaway before you hit constant voltage, the
> > > timer-on-constant-voltage will obviously do you no good.
>
> > But what's the
> > > probability of a thermal runaway during bulk charge? If it happens in
the
> > > constant voltage phase, can the pack voltage drop to the point where
the
> > > timer resets?
>
> Yes. When the batteries are in the finish portion of the charge, they are
> generating the most heat. Thus, they are at the highest temperature during
> this phase. Thus, they are quite likely to go into thermal runaway during
> the finish charge.
>
> If your pack is a little too warm, and you are just over the edge
> for thermal runaway, it will happen during the finish charge (because the
> voltage will dip below the trigger voltage and the timer will reset.) If
> your pack is insanely hot to begin with, you will never reach the trigger
> voltage and the charger will never shut off (because there is no "total
> time" limit timer.) In either case, you pack will be ruined.
>
> Don't be confused. I am talking about lead-acid batteries. (They
> do this just like Ni-Cads.)
>
> > It apparently did on Bill's pack, is it possible with lead?
>
> Yes. See above.
>
>
> >Most certianly if you have your peak voltage set too high. This is the
> >key... All batteries will if you drive them to too high a voltage.
>
> Even very slightly too high. This voltage changes with
temperature
> as well as the age of the batteries. (Yes, I'm still talking about
lead-acid.)
>
> > They do
> >it even faster if you hold them at high voltages for long times.
> >
> >So Yea you can drive PbLa to run a way.
>
> It is easy, actually.
>
>
> > > > That timer latch was pursposely set to unlatch. I wanted it that
way.
> >And
> > > > so
> > > > do about %40 of my installed base.
> > >
> > > Question 2: What advantage is realized by allowing the timer to
unlatch
> >if
> > > the voltage drops? Who are these 40% of your installed base?
> >Marine applications where they have a on board charger, and they want it
to
> >time out shut off and restart at the command of the throttle.
> >Works slick I might add for the "Charge as we go crowd" with Gensets on
> >board.
>
> This makes no sense. If the timer has timed out, the charger does
> not restart if the battery voltage drops. It only resets if the battery
> voltage drops BEFORE it times out.
>
> After time-out, the only way to restart the timer is to turn off
> the charger and turn it back on again.
***** Wrong..
If Dip Switch 8 is on on a Rev 7 and higher controller It will Auto Restart.
Clearly you don't want to do this Bill.
Your does not have this feature.
So... Be Warned it's a documented feature. Setting this up takes some
effort. I dial them into restart at 170 VDC if the peak is set to 191. This
is 13 Yts and pretty healthy battery pack.
I set most here unless I know exactly what the customer needs and wants. I
set them all to OFF when shipped.
Your ease of entering thermal runaway..... Just doesn't stack up with my
experiences. I have to beat on batteries to get them to warm up enough to
Care.
Take this from one who has a 50 Kw charger in his shop....Believe me... I do
have the means.
*****
>
> > >
> > > Question 3 (the big one for me): Since thermal runaway is an unlikely
but
> > > very expensive possibility, what is the best way for me to prevent it
in
> >my
> > > 120 V flooded lead-acid pack? Will the time-from-constant-voltage
timer
> >on
> > > my PFC-20 suffice, or do I need a separate timer in the charger line
cord?
> > >
> >This is really easy... never let your pack get over 150 VDC. And if you
do
> >know that your pack is over 120 Deg F, Don't charge it until it cools.
And
> >don't leave your pack at 150 volts for
> >days. If you want to float your pack drop it down to about 138 volts.
>
> The charger doesn't sense temperature. You can start the charge
> with the pack at some reasonable temperature and have it go over 120 while
> it is charging. (Parked in the hot sun, for example.) It will reach peak
> temperature during the finish charge WHILE YOU ARE NOT THERE.
>
>
> >What this means if you keep the charger set to where you should thermal
> >runaway is a very rare issue on Lead Acid.
>
> It would be even more rare if your finish timer did not reset
> itself. :^)
>
Very ture Bill, but I don't have my finsish voltage set high enough for a
thermal run away in the first place.
And this is the WHOLE point if this thread.
Assume Dip Sw 4 will be the latching voltage option...
Can I ask a couple of questions with out getting Branded any more Bill??
First do you have any clue what your pack temp got to????
What temp do you consider to be "in thermal runaway"? I use 110 to 120 F
for AGM lead Acid, but this is a rough data point.
I could hack a MK2B Reg to lock off the charger at just about any temp, but
it's a 1/4 watt toss type hack using the heatsink temp channel. This would
at least stop the show, and allow things to cool down.
I would also allow the timer to time out locking the charger off until
supervision returns.
It would be cool to actually get enough resolution to track the changing
temp curves to, one detect a thermal event in progress, and two , to use
this as a Safe end of charge should we get enough precision to see the temp
rise bump that happens at every end of charge on a NiCad.
Ohyea and My AGM Yts COOL while being charged. Since I am not sucking 1000
amps from them while on the stinger....
Lets learn from this Bill. Plugging holes in my feature list is why I am
here.
Rich Rudman
Manzanita Micro
--- End Message ---
--- Begin Message ---
>> Raise compression AND advance the sparc?
>>
>> Yup, that'll reduce emissions.... mostly because,
>> once they blow up, they
>> can no longer convert hydrocarbons to mechanical
>> power.
>
> Also many of these motors have 5-1/6-1
> compression ratio's that can easily stand a point or 2
> higher without problems as all better engine have for
> eff and better emissions.
> Many modern low emissions motors now use 10.5-11
> to 1 compression ratio's so 8-1 isn't a big deal, just
> more eff. Many times this can be achieved by just
> removing the head gasket and replacing it with a
> thinner one or of 'Form a Gasket' that's made to do
> this. Many times you must adjust the valves too as
> their distance can change.
Make up your mind Jerry, are you talking about cheap B&S lawnmower engines
or modern (relatively) high efficiency OHV engines?
All of the small OHV engines I've seen are running 8.5:1 compression which
is about as high as you can go on an Air cooled engine without detonation
unless you RETARD the sparc or run higher octane fuel.
If you are going to take one of these OHV engines, INCREASE the
compression and at the same time INCREASE the sparc advance, either you'll
end up with a lot of broken shiny bits or you'll need to run racing fuel
or AVgas in order to get high enough octane.
> Or Peter, would you rather have more pollution?
> How would you solve this problem?
If I was going to use a gasoline engine, I'd use 3 cylinder Geo Metro
engine. It's a relatively small engine with excellent emissions.
Or (my preference) a Diesel engine running biodiesel or WVO, both of which
have fairly low emmisions roughly comparable to a decent auto gas engine.
And, since sulfur is not an issue with these fuels, add either a catalytic
converter or a reactor to further clean up the exhuast.
I've got an old rabbit diesel engine that I'm going to play with when I
get back to the states.
Propane is another possible option, but in the states, you'll have to find
a licensed shop to setup/convert the engine and certify your vehicle.
> It's easy and sometimes funny to criticize but a
> good person would offer a solution too.
> One of my main goals is to get our soldiers,
> country out of future wars over oil, energy which you
> of all people should appreciate I'd think though could
> be wrong.
We are drifting into politics here, but changing US cars alone will have
little effect on our policy in the middle east. The US imports very
little oil from the middle east. Stabilizing the middle east is about
helping the World's economy, not just the US.
China, Japan, and other countries more directly effected by middle eastern
oil, are already heading towards EVs (yeah), it's mostly just the US
that's dragging it's feet.
> EV's with sometimes gens are I believe the way
> out of these and on to a good economy.
I don't know about that, but I agree that plug in hybrids are a good idea
and probably the way of the future. Though I can also see the advantages
of two vehicles with different missions, i.e EVs for around town and ICEs
for long trips.
My current ideas are geared towards EVs with ICE assist for long trips,
possibly making the ICE removeable so you don't have to lug the extra
weight when not needed. I intend to do some experiments to see how much
effect carrying the extra weight has on EV range.
My idea is to use the ICE to directly drive the wheels via a single, or
possibly two speed, transmision and only use the ICE when cruising on the
highway (this allows you to run the ICE at it's sweat spot AND avoid dual
conversion losses). The E-motor will be used in town, at low speed, and
accelerating up to highway speed.
When you encounter hills the E-motor can assist the ICE; down hills and on
the flats, the e-motor can regen to charge the batteries. Add a small,
part time, generator to the ICE for those rare occasions when you run the
pack flat.
> Any good racing Go-cart shop can do these mods
> for you as they do it all the time along with
> converting small engines to methanol for racing so can
> also convert them to ethanol or E85 as it's just a
> matter of changing the carb jet size and advancing the
> timing, both very easy, cheap to do..
Check with those go-kart shops to see how long these engines live with
these modifications.
> So for under $100 you can have a good, eff, low
> polluting engine modified from your industrial engine
> by someone else. Much lower cost if you do your own
> work.
> And using ethanol in a correctly set up engine
> can lower emissions a lot Vs gasoline which is a
> witches brew of chemicals. Same with propane, butane,
> and NG which can be much cleaner than gasoline, diesel
> when done correctly.
Perhaps, though I'd like to see a well-to-wheels (or dirt to wheels)
comparison of ethanol vs gas.
Also, FWIW, even a low emissions honda OHV engine produces about 8 times
as much pollution as a decent auto engine. Simply because it doesn't have
any of the extra emission control devices, etc. of a modern auto engine.
So if you start with one of these and even manage to cut the emissions in
half (doubtful) you are still producing four times as much emissions as
the auto engine. And that is probably the best case scenario.
Personally this is why I like the idea of waste vegetable oil. Since you
are reusing a waste product, all of the energy and emissions produced
prior
to use as a fuel are irrelevant since they are going to happen anyway.
The reports I've seen indicate that even with an ordinary diesel engine,
WVO produces far less polution than Diesel and comparable emissions to a
modern gas engine.
Note: these are TAIL PIPE emissions, so WVO comes out WAY ahead because
you don't have the added polution caused during producion and
transportation (it's already been produced and transported before it
became a waste product)
--- End Message ---
--- Begin Message ---
It's a sepex- 400A 800Hz
The car was converted by Soleq. All the traction components were
manufactured by them.
Marv
> From: "M.G." <[EMAIL PROTECTED]>
> Date: Wed, 06 Jul 2005 18:38:18 -0400
> To: [email protected]
> Subject: 20 yr old 9" DC motor
>
> What are you using for a controller?
> Mike G
>
>
> I just replaced the brushes in my GE sepex. Four pair (eight brushes in
> all). I think it all ran about $130 or so.
>
> Runs a lot better without those rivets dancing on the commutator:^O
>
> Marv
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--- Begin Message ---
Its always good to hear sombody is going to do a conversion ,
that is has a standard tranny is good , do you know the weight on it , ?
What are you looking for it to do , range and speed ?
steve clunn
----- Original Message -----
From: "Chris Seeley" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, July 06, 2005 8:28 AM
Subject: I'm getting closer! (found a donor car) Comments?
Hi list,
I have been offered a 92 Mazda Protégé. The price is right (free). It's
been parked for several years, and it did run when it was parked. It
needed
a water pump, at the time. The code enforcer has given him till this
weekend to get it off of his property, so either I get it or the local
bone
yard does. The body is in excellent shape. I didn't try to start it, as
I
don't care if it runs, but the clutch is stuck. What do you folks
think....
Is this a god car to do? Have any of you converted one?
Best
Chris Seeley
--- End Message ---
--- Begin Message ---
From: Eric Poulsen <[EMAIL PROTECTED]>
Philip Marino wrote:
C = 200 Ahr N = 1.25
I20 = 200 Ahr / 20 hr = 10 A
Cp = (10 A)^1.25 x 20 hr = 355.6 Ahr
This last equation is wrong. The units on both sides of an equation MUST
be the same, for the equation to be correct. Here, we have Ah on the
right side, and (A) ^1.25-h on the left. No engineer would even write out
an "equation " like that. As I was glancing through this, just seeing a
term with units raised to a non-integer power raised a red flag for me.
Not as I see it. On the left side, you have A * 20hours (omitted
exponent for clarity) on the right, you have amp-hours. Both are
amp-hours, as in amps * hours ... ?
Eric - It works it you omit the exponent, but, if you include the exponent(
which is the source of the error) , the units on the left side of the
equation are (A)^N * hours and the units on the right are A*hours. This is
because the exponent applies to the units as well as the numerical value.
This equation can only be true if the exponent is 1.
For example, if N=2 in that equation, you would have units of
Amps*Amps*hours on the left, and Amps*hours on the right. The left side
can never equal the right ( except for the useless case where both sides are
zero)
Also, I'm not sure why a non-integer exponent is so troubling; it's
mathematically valid.
Sure it's mathematically valid. But, it's unusual to see a value with
units raised to a non-integer power. And, it's OK it the other side of the
equation has the same units. But, in this case it doesn't.
This pages clearly indicate that n is a
fractional
power:
http://www.amplepower.com/pwrnews/beer/
http://www.gizmology.net/batteries.htm
They both include the same equation as above. And, it's still wrong, even
though it's on the web. This equation is no more correct than saying that
12 sq. ft = 12 ft ; it's just not as obvious.
If you really want to do this right, try to find some reliable references to
Peukert's work (preferably not on the web) and start from that.
As best I can find (only searching the web, though, so it's still iffy)
Peukert actually applied his exponent ONLY to the ratio of two currents.
Then, the units cancel out (and you get a dimensionless ratio) BEFORE you
apply the exponent. That way the exponent doesn't create some weird units
on one side of the equation, and you end up with the same units on both
sides, regardless of the value of N.
Phil
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--- Begin Message ---
----- Original Message -----
From: "justin vandeusen"
during that time: Has anyone used a dual motor single
transmission setup? If so:
I have a project going on now with Paul of and http://www.paulsexotics.com/
its kind of on hold , The Porsche 912 has 2 8" motors in it , and a 2k 300v
zilla , I have the motors hooked in series as Paul and I are both waiting to
see who will buy the contactors to do the series/parallel switching . This
set up gives lots of torque but not a lot of motor rpm , as each motor sees
only 120v , ( 240 worth of orbitals) . What has this project on hold is that
the clutch can not come close the handling the motor toquire , yes 1st and
2ed it will spin the wheels but runs out of speed very quick , 3ed would be
the gear but even a light touch on the go peddle slips and smokes the
clutch.
steve clunn
1. How difficult was it to setup?
2. Are there more problems with mechanical wear and
tear with a dual setup?
3. Is this a common technology on EVs and hybrids?
Any information regarding this subject would be
greatly appreciated! Thanks your time!
____________________________________________________
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--- Begin Message ---
Hi Ryan,
My rate went from 8c to 12.66c per Kwh, a 58% increase (on a Co-op), I was
told was due to the supplier (AEP) raising their rates by 9% and they had to
mark it up with the transportation (diesel) costs of transporting coal going
up. Sounds like they needed a raise too. So I'm trying to figure out how
to cut costs since my jeep (geo Tracker) is about 600 w per mile and a
cheese wedge or small EV would be 300 w per mile. I also put my geothermal
loop in my septic tank (aka GeoPoop) to improve my Waterfurnace efficiency
(by switching to Gieco) by 20% (tied into the solar panels & water heater
saving 480 watts per hour).
Mark
----- Original Message -----
From: "Ryan Stotts" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, July 06, 2005 5:17 PM
Subject: Re: EV smart car
> Mark Hanson wrote:
>
> > My electric rates just went up 58%
>
> What was the reasoning behind that?
>
--- End Message ---
--- Begin Message ---
The best way to find out how thick your adapter plate should be is, slide the
transmission pilot shaft into the motor pilot bearing. Take measurements from
the transmission bell housing to the rear motor face.
You have some slight adjustment there, as where you don't want to have the
transmission pilot shaft butt up tight in to the pilot bearing.
You will find that this gap will be as large as 2 inches or more. You will
note that on a ICE engine, the crank flange is recessed from the back surface
of a engine which you should take in account. Take a straight edge across the
back of a engine and measure from this point to the crank flange.
This should be the same distance from the EV motor adapter flange to the
transmission bell housing.
Roland
----- Original Message -----
From: David Dymaxion<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Wednesday, July 06, 2005 11:23 PM
Subject: Please critique adapter
Here's my basic idea: Use steel and weld.
More details: 3/8 inch steel (thick enough or too thick?)
Bend a steel sheet into a circle and weld (i.e. make a short steel
pipe), to use as a spacer.
Rough cut an undersized hole in the tranny plate.
Weld the pipe/spacer to the tranny plate.
Machine the edge of the pipe/spacer to the right dimensions to match
the "magic number" flywheel surface to tranny mounting surface.
Machine a 4 inch centering hole and motor bolt holes in motor plate.
Weld the motor plate to the pipe/spacer.
Center the unit on a rotary table on a milling machine, using the 4
inch hole, and machine the tranny plate hole and bolt holes. Weld on
an oversized centering ring, and machine to size. The Porsche centers
the motor with the tranny via a male centering ring on the motor.
Centering on the 4 inch hole and machining the centering ring should
make these two concentric.
Any major oops in there? The benefits are that steel is much cheaper
than aluminum, fewer bolts, and smaller, and hopefully a bit lighter,
than most adapter designs.
One more crucial detail: The porsche tranny is held up at one end, is
bolted directly to the motor, and the motor is help up at the other
end. The motor+tranny assembly tries to rotate about the axles. With
torque multiplication up to about 4500 ft-lbs of torque (drag race
setup with drag tires and a heavy car) goes through the axles. So the
adapter doesn't just resist motor torque, it also has to hold the
motor and tranny together against the axle torque.
Thanks!
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--- Begin Message ---
From: David Dymaxion <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Please critique adapter
Date: Wed, 6 Jul 2005 22:23:00 -0700 (PDT)
Here's my basic idea: Use steel and weld.
More details: 3/8 inch steel (thick enough or too thick?)
Bend a steel sheet into a circle and weld (i.e. make a short steel
pipe), to use as a spacer.
Rough cut an undersized hole in the tranny plate.
Weld the pipe/spacer to the tranny plate.
Machine the edge of the pipe/spacer to the right dimensions to match
the "magic number" flywheel surface to tranny mounting surface.
Machine a 4 inch centering hole and motor bolt holes in motor plate.
Weld the motor plate to the pipe/spacer.
Center the unit on a rotary table on a milling machine, using the 4
inch hole, and machine the tranny plate hole and bolt holes. Weld on
an oversized centering ring, and machine to size. The Porsche centers
the motor with the tranny via a male centering ring on the motor.
Centering on the 4 inch hole and machining the centering ring should
make these two concentric.
Any major oops in there? The benefits are that steel is much cheaper
than aluminum, fewer bolts, and smaller, and hopefully a bit lighter,
than most adapter designs.
This is a great idea. But, I think that, to get any weight reduction using
a steel weldment, you would have to use even thinner material and add
stiffeners (or, "ribs") . That's the real benefit of a weldment - adding
stiffeners, rather than a single heavy plate.
For example, you could use a thinner main tranny plate, and add several
triangular gussets that are welded to the OD of the tube section and the
surface of the tranny plate. ( It would look cool, too). These gussets
could also attach to the backside of the forward ring - that would really
tie everything together.
Otherwise, you're probably better off weight-wise with aluminum.
Here's an example weight and stiffness comparison of steel vs aluminum
plate. ( plain plate, no stiffeners)
A 5/8 inch thick aluminum plate ( 6061) , compared to 3/8 steel, would
have:
Lower weight : 9.0 lb/ft^2 compared to 14.6 lb/ft^2 for the steel (
38% less than the steel)
1.54 times the bending stiffness of the steel plate
1.85 time the bending strength of the steel plate.
Both bending stiffness comparisons are independent of the steel you use,
since the modulus of all steels is the same. ( All steel is 30 Mpsi, all Al
is 10 Mpsi) The bending stiffness is proportional to the cube of the
thickness - that's why the aluminum plate is so much stiffer in this case.
10% more in-plane strength than the steel.
About 1/2 half as stiff in-plane as the steel.
The strengths are based on a yield stress for the steel of 60 Kpsi, and 40
Kpsi for the Al ( 6061-T6).
The lower in-plane stiffness of the aluminum wouldn't matter. The in-plane,
or membrane stiffness of either of these plates is so high ( think of trying
to stretch each plate like a sheet of rubber) that this will make no
difference in real use.
If you add stiffeners, you might be able to go to 1/4 inch steel plate -
then you could possibly end up lighter than the aluminum. ( The stiffeners
could be 3/16 or even 1/8.) I'll bet the tube section could also be 1/4
inch thick or less. A short tube section welded to plates at both ends is
very stiff and strong.
Here's a picture of a weldment I made to connect the comm end of my motor (
ADC 8) to the original right side engine mount ( Toyota Echo)
http://nick.homelinux.net/phil_echo_b_u/Pictures/Adapter_plate3.jpg
The four holes on the right are used to attach it to the motor. The three
holes in the plate at the left (hard to see in this picture) attach to the
bottom side of the OEM engine mount.
By using thin steel plate, and adding stiffeners ( notice the diagonal
stiffener made from a piece of steel angle to prevent the whole thing from
twisting) it ended up lighter than the same part made of simple aluminum
plate, Also, the short stiffener plate ( hard to see - it runs top to
bottom in this picture, about 2/3 of the way to the right) is there to
provide stiffness near one of the mounting holes in the thin ( .105 ") main
plate. There is some stiffener near all of the motor-mounting holes.
This part weights a bit under 3 #, is very stiff, and ( I think) looks good.
And, doing it this way also gave me a chance to work on my welding (torch
- that's all I have).
Phil
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--- End Message ---
--- Begin Message ---
You wrote:
> Cp = (10 A)^1.25 x 20 hr = 355.6 Ahr
> This last equation is wrong.
This is Peukert's Equation:
I ** N * T = Cp (Current raised to the Peukert's constant multiplied by
time equals Peukert's capacity in Ah)
It's the same as the example above. This is the equation you are
claiming is wrong.
It boils down to this:
You're claiming the equation is invalid, and that every source that
indicates the equation is valid is wrong. You're claiming that if
researched, this will be shown to be true. The burden of proof is on
you. You have not cited a single book, article, or website to back up
your assertions.
P.S. I understand your explanations about the equation perfectly -- I
just think you're wrong. I don't see anything at all wrong with
modifying the current with an exponent before using it in an amp-hour
calculation. The whole point of Peukert's equation is to account for
higher currents having a non-linear effect on battery discharge time;
using an exponent provides this non-linearity by providing a greater
exaggeration of the current as it rises.
--- End Message ---
--- Begin Message ---
On 7/7/05, Eric Poulsen <[EMAIL PROTECTED]> wrote:
> You wrote:
>
> > Cp = (10 A)^1.25 x 20 hr = 355.6 Ahr
> > This last equation is wrong.
>
> This is Peukert's Equation:
>
> I ** N * T = Cp (Current raised to the Peukert's constant multiplied by
> time equals Peukert's capacity in Ah)
>
> It's the same as the example above. This is the equation you are
> claiming is wrong.
I think Eric is right. An exponent is simply a way of expressing a
number, it's not an operator or a term. The equation is not
unbalanced by it's inclusion.
That said, algebra class was a long time ago :)
--
EVan
http://www.tuer.co.uk/evs2
--- End Message ---
--- Begin Message ---
Hi Jerry and everyone,
They made a few prototypes to test the marketability
of an electric kit car. After discovering the battery
technology wasnt what they needed, they scrapped the
project. I'm angling for the "hair curl" pick up. the
main bank is (10) 180GXL alphacell gel cells (12V,
[EMAIL PROTECTED], 66lbs each) the controller is a Zapi H2B
[EMAIL PROTECTED] w/regen. Not bad for my first EV huh? Any
predictions? Range? speed? Spontaneous combustion? Any
suggestions for chassis/structural improvement (Im
thinking roll cage over the next couple years)?
Brian B.
--- jerry dycus <[EMAIL PROTECTED]> wrote:
>
> Hi Brian and All,
> --
> With a few mods in power, batts and
> handling,
> it could curl your hair at it's weight?
> Was it a factory EV from Bradley? Some were
> produced that way.
> As it's so light, you don't need a Zilla 2k
> to
> go fast as even a low voltage 1k would do the trick
> with Orbitals or YT batts.
> Or other controllers like the SRE 600 amp
> 96vdc using 8 Orbitals for power and 8 floodeds for
> range depending on what type of EV, range you want
> for
> much less money. You will have no problem smoking
> your
> tires!
> What voltage, controller, batts, charger do
> you have?
> What do you want to do with it?
> You have a very light, aero EV there that
> has
> lots of potential for range or sport or both.
> There are several on the web including a
> very
> nice one by a high school in Melboure, Fla.
> HTH's
> Jerry Dycus
>
> - brian baumel <[EMAIL PROTECTED]> wrote:
>
>
>
>
> ____________________________________________________
> Sell on Yahoo! Auctions no fees. Bid on great
> items.
> http://auctions.yahoo.com/
>
>
____________________________________________________
Sell on Yahoo! Auctions no fees. Bid on great items.
http://auctions.yahoo.com/
--- End Message ---
--- Begin Message ---
From: Eric Poulsen <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: State of Charge calculations
Date: Thu, 07 Jul 2005 07:21:10 -0700
You wrote:
> Cp = (10 A)^1.25 x 20 hr = 355.6 Ahr
> This last equation is wrong.
This is Peukert's Equation:
I ** N * T = Cp (Current raised to the Peukert's constant multiplied by
time equals Peukert's capacity in Ah)
It's the same as the example above. This is the equation you are claiming
is wrong.
It boils down to this:
You're claiming the equation is invalid, and that every source that
indicates the equation is valid is wrong. You're claiming that if
researched, this will be shown to be true.
Yes - that's exactly what I am saying.
The burden of proof is on you. You have not cited a single book, article,
or website to back up your assertions.
No references are necessary to show that an equation must have the same
units on both sides. (And, citing a website certainly wouldn't help -
that's how we got into this mess. )
That is basic to the idea of an equation.
Both sides of an equation are equal; that means: equal value, AND equal
units.
How can 10 Amp-Amp-hours = 10 Amp-hours ? ( That's what happens if N=2 in
that equation) Do you think that is correct?? Is it possible that 10
sq-inches = 10 inches ?? How many chickens equals 20 degrees Faranheit ?
Although I don't really know, I say again that I would be surprised if the
above equation actually is Peukert's Equation. He was most likely an
engineer or scientist, and would not write an "equation" with different
units on both sides.
So, I am not attacking Peukert or his concept that battery capacity is
reduced at increase current draw. Just this particular equation. Most
likely, someone misinterpreted his work, and put it on the web. After,
that, people could just copy it without thinking for themselves.
To summarize, I claim that:
1. The units of that equation are not the same on both sides. ( for values
of N that are not = 1)
and
2. The units of ANY equation must be the same on both sides for it to be
valid.
Do you disagree with either of these statements ?
If so, we must agree to disagree. ( and get back to real EV-related stuff)
Phil
PS. I apologize to all of you if I reacted too strongly ( or harshly) to
this. I have been an engineer, and working with number and calculations
most of my life, and I reacted to this error without considering how others
would feel about it. I just assumed that everyone would also see the
problem, and move on from there.
A little more tact on my part would have been wise.
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