EV Digest 6655
Topics covered in this issue include:
1) Misco Refractometer for Specific Gravity measurements
by JS <[EMAIL PROTECTED]>
2) Re: "largish" brushless motors available
by "Evan Tuer" <[EMAIL PROTECTED]>
3) Re: "largish" brushless motors available
by "Evan Tuer" <[EMAIL PROTECTED]>
4) Re: Fantasy batteries
by robert mat <[EMAIL PROTECTED]>
5) Re: "bulging" case a visual sign of a bad floodie?
by robert mat <[EMAIL PROTECTED]>
6) Re: "largish" brushless motors available
by "Kaido Kert" <[EMAIL PROTECTED]>
7) Re: Oklahoma - Alternative Fuels Act, Regs an' Stuff
by "Bob Rice" <[EMAIL PROTECTED]>
8) Re: "largish" brushless motors available
by "Evan Tuer" <[EMAIL PROTECTED]>
9) Re: Kokam LiPoly Batts
by Marcin Ciosek <[EMAIL PROTECTED]>
10) Prius Hackers needed
by Chip Gribben <[EMAIL PROTECTED]>
11) Re: "largish" brushless motors available
by "Peter Gabrielsson" <[EMAIL PROTECTED]>
12) Lithium production, was: Fantasy batteries
by Christopher Robison <[EMAIL PROTECTED]>
13) Re: EV APU (genset) emissions & FE
by Jeff Major <[EMAIL PROTECTED]>
14) Re: Regen is a bit better than you think
by Tom Watson <[EMAIL PROTECTED]>
15) Re: Misco Refractometer for Specific Gravity measurements
by Frank John <[EMAIL PROTECTED]>
16) HOW TO DRIVE AN EV FOR MAXIMUM RANGE. Re: EVLN(Tofu maker Toya pulses &
glides his hybrid to nenpimania)
by robert mat <[EMAIL PROTECTED]>
17) Re: "largish" brushless motors available
by "Kaido Kert" <[EMAIL PROTECTED]>
18) Re: Balancing Lithium batterys - how does this work?
by "Scott Littledike" <[EMAIL PROTECTED]>
19) Re: EV APU (genset) emissions & FE
by john fisher <[EMAIL PROTECTED]>
20) RE: HOW TO DRIVE AN EV FOR MAXIMUM RANGE. Re: EVLN(Tofu maker Toya
pulses & glides his hybrid to nenpimania)
by "Paschke, Stephen" <[EMAIL PROTECTED]>
21) Re: Wise A** Bad Boy Charger
by Tim Humphrey <[EMAIL PROTECTED]>
--- Begin Message ---
I got my Misco Model 7064VP-Plus yesterday. (139.98 included shipping).
After checking the specific gravity of 33 flooded cells I will never use
a float type hydrometer again!
1. Ease of use.
2. Accuracy
3. Cleaner. No dripping acid.
4. The applicator can be used to check acid level by watching for the
meniscus to form and seeing
how much farther down to the top of the plates.
5. Faster.
6. Temperature compensated.
7. It also works for anti-freeze.
8. Easy to check calibration using distilled water.
I ordered it at www.misco.com
Thanks for the suggestion!
John in Sylmar, CA
PV EV
--- End Message ---
--- Begin Message ---
On 4/11/07, Kaido Kert <[EMAIL PROTECTED]> wrote:
Seriously, people have shown interest in UQM PM brushless motors for
example, but UQM isnt selling.
The RC BLDC motors are (somewhat) similar in operating principle and
construction, and its reasonable that one or few manufacturers would
be willing to "grow" and sell for EV hobbyists as well. The power
range already starts to show up, with enough interest, experimentation
and trial&error they might even be willing to design some stuff for
There's a group which are building their own motors (having
laminations pressed and so on) - there is software and instructions
for designing them: http://groups.yahoo.com/group/lrk-torquemax/
- this was introduced on this list by Ron van Sommeren some time ago.
I think that this is one of the motors which has come from this ethos,
a 30kW peak motor which weighs only 7.5kG.
www.rc-unionen.dk/nytforum/uploads/9302/2006918173952_Aspach%202006%201.JPG
http://www.rs-e-motoren.de/joomla/index.php?option=com_content&task=view&id=86&Itemid=79
Even this monster motor is small in conventional EV scale, but it
shows what could be possible (e.g. for a geared hub motor) with the
appliance of science :)
--- End Message ---
--- Begin Message ---
Correction, that motor is rated 30kW for 30 minutes.. That's about
the same as my EV, except its motor weighs 72kG rather than 7.5 :)
On 4/11/07, Evan Tuer <[EMAIL PROTECTED]> wrote:
On 4/11/07, Kaido Kert <[EMAIL PROTECTED]> wrote:
> Seriously, people have shown interest in UQM PM brushless motors for
> example, but UQM isnt selling.
> The RC BLDC motors are (somewhat) similar in operating principle and
> construction, and its reasonable that one or few manufacturers would
> be willing to "grow" and sell for EV hobbyists as well. The power
> range already starts to show up, with enough interest, experimentation
> and trial&error they might even be willing to design some stuff for
There's a group which are building their own motors (having
laminations pressed and so on) - there is software and instructions
for designing them: http://groups.yahoo.com/group/lrk-torquemax/
- this was introduced on this list by Ron van Sommeren some time ago.
I think that this is one of the motors which has come from this ethos,
a 30kW peak motor which weighs only 7.5kG.
www.rc-unionen.dk/nytforum/uploads/9302/2006918173952_Aspach%202006%201.JPG
http://www.rs-e-motoren.de/joomla/index.php?option=com_content&task=view&id=86&Itemid=79
Even this monster motor is small in conventional EV scale, but it
shows what could be possible (e.g. for a geared hub motor) with the
appliance of science :)
--- End Message ---
--- Begin Message ---
I like your Header, Fantasy Batteries.
No, I don't like Lithium, because it comes from only two countries, and it
would be too easy for a corporation, or a war, to bottle up supply, and Lithium
EV's would end up with another Killed Electric Car.
IMHO, we have to stay and perfect the only battery that is cheaper than
gasoline: Lead Acid.
Well, our Vancouver hobby group has a kind of "fantasy battery". We've also got
three battery breakthroughs. Care to read about it?
EV Diary, part V (lots of photos), link
http://evdiary-revived-pickup.blogspot.com/
Check out our trip photos, click on link above. People love to talk to us about
this, especially after the CBC aired David Attenborough's complete "The Truth
About Climate Change", of which, part two was about solving what the scientists
called, "a foreseeable catastrophe."
Cheers, Rob
David Hankins <[EMAIL PROTECTED]> wrote: Just browsing around and came on
these. Made me drool(more). :)
http://www.saftbatteries.com///060-MS_Military/50-30-10_produit.asp?sSegment
=Military+%26+Defence&sSegmentLien=10%2D10%2D10%5Fmilitary%2Easp&sSecteurLie
n=50%2D10%2D10%5FNaval%5Fapplication%2Easp&Secteur=Naval+application&Intitul
e_Produit=RA3
If my calculations are correct a 120v single string pack would weigh ~340#
and do 120 amps continuous for an hour + or 70 amps for 2 hours. Compared to
this Li-Ion:
http://www.saftbatteries.com/130-Catalogue/PDF/mp_176065_integration.pdf
which looks pretty potent to me and would do the equivalent output at ~850#
(2742 cells).
I'm not even going to try and imagine what they cost.
Good hunting
David Hankins
The island-country of Kiribati will be sunk in 15 years
by climate change. May be one solution:
Newspapers and TV news coverage of
our 'no cost' battery for electric vehicles,
solving global warming and pollution at once..
http://tv-news-revived-batteries.blogspot.com/
---------------------------------
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Try the free Yahoo! Mail Beta.
--- End Message ---
--- Begin Message ---
Also, on VRLAs (sealed) on ebikes, my guess is that the valves aren't
releasing. Very cheap build, and mfg cheated by not putting in valves, imho,
like on the Raylight ebikes. Raylight vendor told me 100% of his batteries
bulged at the end of battery life.
David Roden <[EMAIL PROTECTED]> wrote: I think this results from positive grid
corrosion - typically a symptom of
chronic overcharging.
David Roden - Akron, Ohio, USA
EV List Administrator
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The island-country of Kiribati will be sunk in 15 years
by climate change. May be one solution:
Newspapers and TV news coverage of
our 'no cost' battery for electric vehicles,
solving global warming and pollution at once..
http://tv-news-revived-batteries.blogspot.com/
---------------------------------
Be a PS3 game guru.
Get your game face on with the latest PS3 news and previews at Yahoo! Games.
--- End Message ---
--- Begin Message ---
On 4/11/07, Evan Tuer <[EMAIL PROTECTED]> wrote:
> Even this monster motor is small in conventional EV scale, but it
> shows what could be possible (e.g. for a geared hub motor) with the
> appliance of science :)
Yes, i know about the lrk-torquemax thing. Thanks for the motor links.
The listed price is a tad expensive though 130$/KW, but might be well
worth it.
My 150cc Honda NSR "pocket rocket" has 29KW currently, and does
180km/h if pushed .. i wonder what that it would do with one of
these... hmm.
-kert
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Michael Barkley" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, April 11, 2007 6:42 AM
Subject: OT: Oklahoma - Alternative Fuels Act
> Here's some snips from the Alternative Fuels Act regarding EV's. When I
found this out, I was really upset with Oklahoma. If there's an attorney in
the group, can some OKIES, get some advice? I could private you the entire
statute. I think it's the only state that has done this. This is stated
in Statues: 74-130.12 through 74-130.24:
> Hi EVerybody;
Scary? You Bet! IF that were to go nationwide!? I guess a guy in Okie
COULD build his own car as a hobbiest? But not sell/ service them?Don't we
have a few Okie Listers? If you want to do your own dental work, nothin'
stopping you?Too.
In the same vein; the Electrical Regs that styfle the plug in of EV's
EVen though the RV Industry uses outdoor( I know of very few Win-a-bagels
used INDOORS?) You can plug THEM in almost anywhere.I think the Greyhound
buzz size ones use 50 amp plugs, 240 volts? For their Jacuzzi, wine celler,
heated pool? SOOOO to symplify the charging thing, we COULD just use RV
plugs EVerywhere. But, NO that's too easy!
Seeya
Bob
> §74-130.12. Legislative intent.
Bla Bla Bla
--- End Message ---
--- Begin Message ---
On 4/11/07, Kaido Kert <[EMAIL PROTECTED]> wrote:
On 4/11/07, Evan Tuer <[EMAIL PROTECTED]> wrote:
> > Even this monster motor is small in conventional EV scale, but it
> > shows what could be possible (e.g. for a geared hub motor) with the
> > appliance of science :)
Yes, i know about the lrk-torquemax thing. Thanks for the motor links.
The listed price is a tad expensive though 130$/KW, but might be well
worth it.
Remember that it's a hand-built motor, with no doubt a lot of research
and tinkering time involved in designing it. Although it must have
expensive magnets, the rest of the construction and the amount of
material involved does not look like anything inherently expensive or
difficult.
In fact, it looks simpler than our traditional motors: who here is
designing and making series wound DC motors from scratch, and how much
would a one-off cost if you did?!
And as you say, even at that price it's obviously got a market due to
the extreme power/weight ratio, even though there isn't an off the
shelf controller..
My 150cc Honda NSR "pocket rocket" has 29KW currently, and does
180km/h if pushed .. i wonder what that it would do with one of
these... hmm.
Don't forget "some" A123 cells to go with it :)
--- End Message ---
--- Begin Message ---
Steve,
1. I asked friends in Kokam for cells you wanted datasheets with different
currents discharge results so right after I get them I'll e-mail you
2. so far cells I used have Ri (measured at 1kHz) below 1 mohm and generally
cells of one type are no different from eachother more than 10%
3. as was mentioned here, for ProEV Kokam used titanate spinel anode material
so the acceptable current was enormous but even the typical Kokam NCM-LiC
chemistry is capable for high constant discharge currents (it's worth to
notice that Kokam measures its cells capacity at 1C discharge current)
4. If you want to purchase single amount of cells Kokam will send you to local
distributors. Prices are really high... Predicting the future trend is like
betting on lottery.
5. BMS - situation is quite opposite ;) than you ask.
6. If you fulfill factory's conditions (like operational temperature regime,
charging method, voltage limits etc.) you will even 800 FULL cycles with DOD
not higher than 80%.
I can not confirm it right now but so far I've no reason to doubt.
Rgs,
Marcin
--- End Message ---
--- Begin Message ---
Anyone know of anyone who hacked into their Prius to increase the
mileage?
I just got a call from the Washington Post and they want to write a
story on this, particularly anyone in the DC area who has hacked into
one.
I personally don't know anyone around here who has.
I'm aware of the Plug-In Priuses that have been done. And the only
one I know of in the DC area is the one owned by Fairfax County that
had their Prius converted by Hymotion (sp?) in Canada.
But I think they are really looking for people who have actually
hacked into the system to tweak it to improve the mileage. I'm not
even sure if this is possible or not. It would seem you would be
limited by the capacity of the existing battery pack and messing with
the air/fuel mixture may cause performance issues. So it maybe like
drawing blood out of a rock.
So if anyone has any reason why it can't easily be done that would be
good to know too. Lee? The Post maybe chasing a myth and this would
be a good time to nip it. We need to fight the myths as well as tout
technological gains.
Email me off list or call if you are interested or know someone who
has or have any information that would help
Thanks,
Chip Gribben
240-687-1678
Electric Vehicle Association of Washington DC
http://www.evadc.org
NEDRA
http://www.nedra.com
--- End Message ---
--- Begin Message ---
Don't forget that RC airplane brushless controllers are usually
sensorless designs. In order to find the rotor position they will jerk
the motor back and forth for a few seconds before starting up. This is
obviously not very desirable in a car.
On 4/11/07, Kaido Kert <[EMAIL PROTECTED]> wrote:
hey,
i stumbled on these: RC BLDC motor makers have scaled their offerings
up increasingly, and now you can get a complete 15KW system from them.
for example Hacker A200 motor with a MasterSpin 300 controller would
cost around $1600
With a pair of those, you could move a light car.
There are other alternatives ( Plettenburg has Predator 37/06 in the
same power range )
So for a $3200, you'd be running what is essentially a 30KW AC system ( as
BLDC motors differ from PMAC motors only in winding distributions on
stator )
There would be quite a lot of mechanical work though, as the motors
are intended to be mounted on RC airplanes. They are very lightweight
for their available max power, however.
Now, if the demand is there, i believe those same manufacturers would
be willing to ship a line of motors and controllers modified for EV
apps.
anyone interested ?
-kert
--
www.electric-lemon.com
--- End Message ---
--- Begin Message ---
On Wed, 2007-04-11 at 08:22 -0700, robert mat wrote:
> No, I don't like Lithium, because it comes from only two countries, and it
> would be too easy for a corporation, or a war, to bottle up supply, and
> Lithium EV's would end up with another Killed Electric Car.
For a somewhat more informed representation of worldwide Lithium
production:
http://minerals.usgs.gov/minerals/pubs/commodity/lithium/lithimcs07.pdf
http://minerals.usgs.gov/minerals/pubs/commodity/lithium/lithimyb05.pdf
http://minerals.usgs.gov/minerals/pubs/commodity/lithium/
http://en.wikipedia.org/wiki/Lithium
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
--- End Message ---
--- Begin Message ---
Hi John,
I use a D&D SepEx motor on an IUV (industrial utility vehicle) with a Sevcon
controller and it works very well. It does regen nicely. I have also used it
with the Curtis SepEx controller. Also works well. This is at 48 volts.
Sevcon does have a 72 volt version. I am not sure of motors available for
that. This is much smaller than an on-road EV and has a top speed of about 15
mph. I run the motor TENV (totally enclosed, non ventilated). And also limit
it to 300 amps, where max on the controller is 500 (maybe 600). Controller
never gets hot. Running a lot of ventilation on the motor, the system may work
for smaller/slower on-road EVs.
Jeff
john fisher <[EMAIL PROTECTED]> wrote:
<snip>
How is the D&D sepex-regen-controller option, anybody used it?
JF
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--- End Message ---
--- Begin Message ---
Hi
on my electric moped I found ways to increase my use of regen and for
just this reason... on my way home I would go up a 1/2 mile hill and
then come down the other side closer to my house... the regen brought
the battery up again and I could ride at 30kph the rest of the way
home... on a normal run without climbing and coming down the hill the
batteries would be lowering the voltage so I could only go about
15kph max speed... that made quite a difference for me! of course
hill climbing on one of those isn't easy(you slow down going up
hill), but it was still worth doing.
Tom
-----------<<<>>>-----------
You get a bit more than you would first think from regen.
Around town in stop-and-go traffic, you would calculate that you
would save about 10% or 15%. Then you travel that extra 15%. While
traveling that extra 15%, you get 15% more of that!
Also, batteries really like to "flip over" and charge for just a bit
during discharge. They are not simple beings chemically, and the
brief charge during regen, especially for lead-acid batteries, makes
a greater range increase than you would expect, when just using a
simple calculation. Also, you move to a different part of the
Puekert's curve on the batteries, helping just a bit more.
Al these "non-linear" effects work together to add perhaps an extra
5% that you would not at first calculate.
On the highway, or in light traffic that allows you to drive
efficiently without using the brakes, regen makes no difference. It
is also expensive to add to a DC drive system. It is generally much
cheaper to simply add another battery or two.
Bill Dube'
--- End Message ---
--- Begin Message ---
I've used this model a lot while winterizing boats and checking freeze
protection. It's nice to be able to write down an actual number in case
something happens when a boat's in storage. I agree that they're a great tool
and well worth the money.
----- Original Message ----
From: JS <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Wednesday, April 11, 2007 10:32:35 AM
Subject: Misco Refractometer for Specific Gravity measurements
I got my Misco Model 7064VP-Plus yesterday. (139.98 included shipping).
After checking the specific gravity of 33 flooded cells I will never use
a float type hydrometer again!
1. Ease of use.
2. Accuracy
3. Cleaner. No dripping acid.
4. The applicator can be used to check acid level by watching for the
meniscus to form and seeing
how much farther down to the top of the plates.
5. Faster.
6. Temperature compensated.
7. It also works for anti-freeze.
8. Easy to check calibration using distilled water.
I ordered it at www.misco.com
Thanks for the suggestion!
John in Sylmar, CA
PV EV
____________________________________________________________________________________
8:00? 8:25? 8:40? Find a flick in no time
with the Yahoo! Search movie showtime shortcut.
http://tools.search.yahoo.com/shortcuts/#news
--- End Message ---
--- Begin Message ---
This post could be better titled, perhaps as: HOW TO DRIVE AN EV FOR MAXIMUM
RANGE.
If you've been watching an ammeter carefully, you can see how its possible to
reduce amps by ~80% at little cost in speed, by coasting, once the EV has gone
up to speed (assuming no regen brakes. My motor is an Advanced 9 inch.)
Its a sobering lesson for gasoline drivers: Seems that driving in the "normal"
way is burning up gasoline needlessly. Is there a way to have an ammeter-like
gauge for gasoline cars?
Rob Matthies
bruce parmenter <[EMAIL PROTECTED]> wrote: EVLN(Tofu maker Toya pulses & glides
his hybrid to nenpimania)
[The Internet Electric Vehicle List News. For Public EV
informational purposes. Contact publication for reprint rights.]
--- {EVangel}
http://www.iht.com/articles/2007/04/05/business/sxhybrid.php
Mileage maniacs push limits of hybrids
By Terje Langeland Bloomberg News April 5, 2007
TOKYO: Toyota Motor says its Prius gasoline-electric hybrid car
can get about 55 miles to the gallon, making it one of the most
fuel-efficient cars on the road. That is not good enough for
Takashi Toya.
Toya, a 56-year-old manager for a tofu maker in central Japan,
puts special tires on his Prius, tapes plastic and cardboard over
the engine and blocks the grill with foam rubber. He drives
without shoes and hacks into his car's computer - all in the
pursuit of maximum distance with minimum gasoline.
Toya is one of about 100 nenpimania, Japanese for "mileage
maniacs," or hybrid owners who compete against each other to
squeeze as much as 115 miles per gallon out of their cars. In a
country where gasoline costs more than $4 a gallon, at least $1
more than the average U.S. price, enthusiasts tweak their cars
and hone driving techniques to cut fuel bills and gain bragging
rights.
"My wife thinks I've joined some strange secret society," Toya
said last January at a nenpimania gathering in Nagoya in central
Japan.
Mileage maniacs are not alone in pushing the limits of hybrid
vehicles. As the U.S. automakers General Motors and Ford Motor
race to introduce their own models, first rolled out by Japanese
companies in 1997, engineers at Toyota and Honda Motor are trying
to increase hybrid performance to maintain their advantage.
[...]
Hybrids combine a conventional gasoline engine with an electric
motor. The electric motor powers the vehicle at low speeds, and
the gasoline engine kicks in as the car accelerates. The motor
uses the motion of the wheels to recharge the batteries.
[...]
While the nenpimania may take things to extremes, there is a long
history of car owners tinkering with their machines to improve
gas mileage.
"The Gas Mileage Bible" (Infinity Publishing, 2006) promises to
help drivers improve fuel efficiency by more than 30 percent. It
is the latest in a line of books stretching back to at least
1942, when an American author named Lee Richter published a
64-page pamphlet on increasing tire and gas mileage to help save
resources for the U.S. war effort.
Since the 1997 release of the Prius, the first mass-market
hybrid, owners in Japan and elsewhere have fiddled with their
cars to raise mileage and shared tips, including the best driving
techniques, over the Internet. The mileage maniacs strive to
perfect what they call the "pulse and glide" driving method.
On a chilly Saturday afternoon in Aichi Prefecture, a short drive
from Toyota's world headquarters in Toyota City, Toya removes his
right shoe to demonstrate. Pulsing and gliding demands
sensitivity when pushing or releasing the accelerator, so only
his big toe touches the pedal.
Toya accelerates, or pulses, to 29 mph, then glides down to 25
mph before pulsing again. The car uses no fuel when gliding.
While driving, Toya monitors three pocket-sized electronic
gadgets designed by Yoshiyuki Mimura, a fellow hybrid enthusiast.
The dashboard devices use the car's computer to display engine
rotation speed, coolant temperature, accelerator position, brake
pressure and battery charge.
[...]
"We listen to our customers' opinions and accept them as
materials for product development," a Toyota spokeswoman, Shiori
Hashimoto, said in response to questions about the mileage
maniacs.
Toyota and other Japanese automakers are focusing on improving
hybrid batteries and making the vehicles cheaper, Endo said. The
cars now cost about �600,000, or $5,100, more than the equivalent
conventional vehicles.
Toyota plans to introduce a new Prius by 2009 that will be
smaller and cheaper, Endo said. The mileage maniacs say they look
forward to the challenge of improving its fuel efficiency.
"The vehicle will be high-tech," said the enthusiast, Mimura. "I
think it'll be more difficult to hack."
Copyright � 2007 the International Herald Tribune All rights
reserved
-
Bruce {EVangel} Parmenter
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor & AFV newswires
. (originator of the above ASCII art)
===== Undo Petroleum Everywhere
: MEPIS Linux & WiFi powered :
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The island-country of Kiribati will be sunk in 15 years
by climate change. May be one solution:
Newspapers and TV news coverage of
our 'no cost' battery for electric vehicles,
solving global warming and pollution at once..
http://tv-news-revived-batteries.blogspot.com/
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--- End Message ---
--- Begin Message ---
There are ones with hall sensors available, and adding three sensors
to an existing motor shaft does not break the bank either. Sensored
design should be better anyway for better low-speed control and
torque.
BTW, most of the RC ESCs or controllers drive the motors using
trapezoidal commutation, but there are some available that drive with
sine wave which makes for even better efficiency , lower losses in
motor and thus lower heating, and also makes the torque smoother (
less or no "cogging" )
-kert
On 4/11/07, Peter Gabrielsson <[EMAIL PROTECTED]> wrote:
Don't forget that RC airplane brushless controllers are usually
sensorless designs. In order to find the rotor position they will jerk
the motor back and forth for a few seconds before starting up. This is
obviously not very desirable in a car.
On 4/11/07, Kaido Kert <[EMAIL PROTECTED]> wrote:
> hey,
>
> i stumbled on these: RC BLDC motor makers have scaled their offerings
> up increasingly, and now you can get a complete 15KW system from them.
> for example Hacker A200 motor with a MasterSpin 300 controller would
> cost around $1600
> With a pair of those, you could move a light car.
> There are other alternatives ( Plettenburg has Predator 37/06 in the
> same power range )
>
> So for a $3200, you'd be running what is essentially a 30KW AC system ( as
> BLDC motors differ from PMAC motors only in winding distributions on
> stator )
> There would be quite a lot of mechanical work though, as the motors
> are intended to be mounted on RC airplanes. They are very lightweight
> for their available max power, however.
> Now, if the demand is there, i believe those same manufacturers would
> be willing to ship a line of motors and controllers modified for EV
> apps.
>
> anyone interested ?
>
> -kert
>
>
--
www.electric-lemon.com
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Many thanks for your replies, they have been extremely helpful!
So to summarise, you either pause charging to bleed voltage from the highest
cell and waste this energy, or more efficiently, use some sort of relay
circuit to transfer voltage from say the highest cell to the lowest (with
current regulation obviously, e.g. a resistor/chip)
I was thinking of building a charger for myself, that monitors the cell
voltages - when one cell reaches sat 3.6V, charging would be stopped and
transferred to the lowest cell, until the lowest cell is close to the
average of the string. charging would then continue etc until all cells are
above say, 3.55V but below 3.6V?
Good point about temperature variation - i would not be using this BMS
during actual battery use so i would hope that temperature variation would
be minimal.
As for the question abut charging cells in parallel banks, this is a good
idea as it is self regulating but i can see the downside being that the Ah
rating of the bank would be large, and you would therefore need a high
current charger = expensive components
Many thanks once again for the excellent replies!
Scott
From: Ian Hooper <[EMAIL PROTECTED]>
Subject: Re: Balancing Lithium batterys - how does this work?
Date: Mon, 9 Apr 2007 23:49:12 +0800
To: ev@listproc.sjsu.edu
On 09/04/2007, at 9:37 PM, Scott Littledike wrote:
> Hi there,
>
> I have been reading the recent thread on charging lithium batteries
> and was interested in how they should be balanced, what the process
> is etc. For example,from what i understand the A123 cells need a
> constant current charge to 3.6V. (please correct me if im wrong)
Yep that's correct, 3.6 volts for the A123 cells, though the peak
voltage does vary for different lithium chemistries.
The charging scheme for lithiums is known as "constant current,
constant voltage". As I understand it, for the first stage of
charging the charger needs to adjust its voltage to maintain a
constant current until the cells reach a peak voltage, then stage 2
is holding that voltage while the charge current tapers off. Charging
terminates when the current has dropped off sufficiently, e.g to
about 1/10th the original current.
> So, the basic job of a balancer is to ensure none of the cells are
> overcharged above 3.6V, and is to move charge into the least
> charged cells? how would this be performed - during the charging
> process i assume?
The most common charge balancing method is shunt or bleed, a form of
passive balancing, whereby each cell has its own little monitoring
circuit able to bypass the cell or bleed off the charge current once
the cell reaches it's target voltage to avoid overcharging. What you
speak of (moving charge into the least charged cells) is active
balancing, and is less common because it's much harder. In fact I
don't really know how they do it.. anyone?
> Would a balancer scan each individual cell voltage, and stop
> charging if any of the cells were overcharged?
It's best for the charger to keep going until all the cells are
charged, and have the battery management systems bypass any fully
charged cells to avoid overcharging. But yes, the BMS does have to
monitor each individual cell voltage in some way or another.
Also, the BMS should definitely be capable of isolating the pack (e.g
opening the main contactor) when any cell reaches it's lowest voltage
point (2.0 volts for the A123 cells) to avoid damage due to over-
discharging.
> Then, to top up the least charged cell - would the balancer charge
> this cell individually, or would say, the cell be connected with
> another in parallel (with some form of current limiting) to move
> charge across?
Yeah, not sure. It's tricky because the cells are always connected
together in the pack so you always have different voltage potentials,
so you can't easily transfer charge between them. You'd need some
form of isolated charge transfer system, maybe relays and
capacitors..? If anyone knows how active charge balancing works I'd
be keen to know too!
-Ian
Message-ID: <[EMAIL PROTECTED]>
Date: Mon, 9 Apr 2007 11:14:15 -0700
From: "Peter Gabrielsson" <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Subject: Re: Balancing Lithium batterys - how does this work?
MIME-Version: 1.0
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> Yeah, not sure. It's tricky because the cells are always connected
> together in the pack so you always have different voltage potentials,
> so you can't easily transfer charge between them. You'd need some
> form of isolated charge transfer system, maybe relays and
> capacitors..? If anyone knows how active charge balancing works I'd
> be keen to know too!
There's a number of ways to do this. Lee Hart's battery balancer uses
a charger that is powered off of the full pack and switched to the
weak cell with relays. A microprocessors measures the cell voltages
and determines which cell need to be boosted.
Another way is to switch an energy storage device like a capacitor
from cell to cell, the capacitor will be charged from the highest
potential cell and discharged on the lower potential cells, thus
eventually equalizing the pack. This is not an ideal system for EVs
though, the equalizing is generally to weak to extend your range while
driving.
The reason to use active balancing is to extend your range. In a long
series string of batteries the weakest battery determines your range,
when the weak battery reaches its cut off voltage you have to stop
driving, even if the rest of the pack has 50% charge left, or you'll
kill the weak cell and in case of lithium; that may result in a fire.
By using a Lee Hart style balancer you can prop up the weak cell and
keep driving.
-Peter
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thanks Jeff.
The dealer, who it seems may never have actually sold one ( !?) is saying he can do a 72-96 V system, using I think a
matched Curtis controller. The prices are in the same ballpark as the less-expensive DC motors with a common controller,
though I better recheck the output numbers to make sure. My application is aimed at less than 1200-1500 lbs total
vehicle weight, less than 50 mph top speed, and minimal EE knowledge. and low-bucks too.
I got no answer from D&D when I asked :(
JF
Jeff Major wrote:
Hi John,
I use a D&D SepEx motor on an IUV (industrial utility vehicle) with a Sevcon controller and it works very well. It does regen nicely. I have also used it with the Curtis SepEx controller. Also works well. This is at 48 volts. Sevcon does have a 72 volt version. I am not sure of motors available for that. This is much smaller than an on-road EV and has a top speed of about 15 mph. I run the motor TENV (totally enclosed, non ventilated). And also limit it to 300 amps, where max on the controller is 500 (maybe 600). Controller never gets hot. Running a lot of ventilation on the motor, the system may work for smaller/slower on-road EVs.
Jeff
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There is a gauge for ICE's. It is a vacuum gauge or at least based on vacuum.
I remember my cousins 79 chevy Malibu having one.
> Stephen Paschke
> DAR, ERISA, Plan Review, and IPI/ICTMS support,
>TIAA-CREF Denver
> Senior Consultant
> Keane, Inc.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of robert mat
Sent: Wednesday, April 11, 2007 9:43 AM
To: ev@listproc.sjsu.edu
Subject: HOW TO DRIVE AN EV FOR MAXIMUM RANGE. Re: EVLN(Tofu maker Toya pulses
& glides his hybrid to nenpimania)
This post could be better titled, perhaps as: HOW TO DRIVE AN EV FOR MAXIMUM
RANGE.
If you've been watching an ammeter carefully, you can see how its possible to
reduce amps by ~80% at little cost in speed, by coasting, once the EV has gone
up to speed (assuming no regen brakes. My motor is an Advanced 9 inch.)
Its a sobering lesson for gasoline drivers: Seems that driving in the "normal"
way is burning up gasoline needlessly. Is there a way to have an ammeter-like
gauge for gasoline cars?
Rob Matthies
bruce parmenter <[EMAIL PROTECTED]> wrote: EVLN(Tofu maker Toya pulses & glides
his hybrid to nenpimania)
[The Internet Electric Vehicle List News. For Public EV
informational purposes. Contact publication for reprint rights.]
--- {EVangel}
http://www.iht.com/articles/2007/04/05/business/sxhybrid.php
Mileage maniacs push limits of hybrids
By Terje Langeland Bloomberg News April 5, 2007
TOKYO: Toyota Motor says its Prius gasoline-electric hybrid car
can get about 55 miles to the gallon, making it one of the most
fuel-efficient cars on the road. That is not good enough for
Takashi Toya.
Toya, a 56-year-old manager for a tofu maker in central Japan,
puts special tires on his Prius, tapes plastic and cardboard over
the engine and blocks the grill with foam rubber. He drives
without shoes and hacks into his car's computer - all in the
pursuit of maximum distance with minimum gasoline.
Toya is one of about 100 nenpimania, Japanese for "mileage
maniacs," or hybrid owners who compete against each other to
squeeze as much as 115 miles per gallon out of their cars. In a
country where gasoline costs more than $4 a gallon, at least $1
more than the average U.S. price, enthusiasts tweak their cars
and hone driving techniques to cut fuel bills and gain bragging
rights.
"My wife thinks I've joined some strange secret society," Toya
said last January at a nenpimania gathering in Nagoya in central
Japan.
Mileage maniacs are not alone in pushing the limits of hybrid
vehicles. As the U.S. automakers General Motors and Ford Motor
race to introduce their own models, first rolled out by Japanese
companies in 1997, engineers at Toyota and Honda Motor are trying
to increase hybrid performance to maintain their advantage.
[...]
Hybrids combine a conventional gasoline engine with an electric
motor. The electric motor powers the vehicle at low speeds, and
the gasoline engine kicks in as the car accelerates. The motor
uses the motion of the wheels to recharge the batteries.
[...]
While the nenpimania may take things to extremes, there is a long
history of car owners tinkering with their machines to improve
gas mileage.
"The Gas Mileage Bible" (Infinity Publishing, 2006) promises to
help drivers improve fuel efficiency by more than 30 percent. It
is the latest in a line of books stretching back to at least
1942, when an American author named Lee Richter published a
64-page pamphlet on increasing tire and gas mileage to help save
resources for the U.S. war effort.
Since the 1997 release of the Prius, the first mass-market
hybrid, owners in Japan and elsewhere have fiddled with their
cars to raise mileage and shared tips, including the best driving
techniques, over the Internet. The mileage maniacs strive to
perfect what they call the "pulse and glide" driving method.
On a chilly Saturday afternoon in Aichi Prefecture, a short drive
from Toyota's world headquarters in Toyota City, Toya removes his
right shoe to demonstrate. Pulsing and gliding demands
sensitivity when pushing or releasing the accelerator, so only
his big toe touches the pedal.
Toya accelerates, or pulses, to 29 mph, then glides down to 25
mph before pulsing again. The car uses no fuel when gliding.
While driving, Toya monitors three pocket-sized electronic
gadgets designed by Yoshiyuki Mimura, a fellow hybrid enthusiast.
The dashboard devices use the car's computer to display engine
rotation speed, coolant temperature, accelerator position, brake
pressure and battery charge.
[...]
"We listen to our customers' opinions and accept them as
materials for product development," a Toyota spokeswoman, Shiori
Hashimoto, said in response to questions about the mileage
maniacs.
Toyota and other Japanese automakers are focusing on improving
hybrid batteries and making the vehicles cheaper, Endo said. The
cars now cost about �600,000, or $5,100, more than the equivalent
conventional vehicles.
Toyota plans to introduce a new Prius by 2009 that will be
smaller and cheaper, Endo said. The mileage maniacs say they look
forward to the challenge of improving its fuel efficiency.
"The vehicle will be high-tech," said the enthusiast, Mimura. "I
think it'll be more difficult to hack."
Copyright � 2007 the International Herald Tribune All rights
reserved
-
Bruce {EVangel} Parmenter
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On Wed, 11 Apr 2007 10:00:41 -0400 (EDT), Lee Hart <[EMAIL PROTECTED]> wrote:
> From:
>> Can a 48 volt Lester automatic charger be used as a Wise A**
>> Bad Boy on a 36 volt pack?
>
> It will work, but will fry your batteries the first time you forget to
> turn it off in time!
>
>
> --
> "Those who say it cannot be done should not interrupt the one who is
> doing it." -- Chinese proverb
>
Does the Lester charger reset (turn back on) after a power outage?
If so, this may help;
http://members.alcisp.com/[EMAIL PROTECTED]/mowerinst.doc
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Stay Charged!
Hump
I-5, Blossvale NY
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