EV Digest 4941
Topics covered in this issue include:
1) Re: Myers motors update
by "Rich Rudman" <[EMAIL PROTECTED]>
2) Re: Question about MK battery AGMs and Gel cells
by <[EMAIL PROTECTED]>
3) Let's be good out there! was Re: Myers motors update
by "Clyde R. Visser, P.E." <[EMAIL PROTECTED]>
4) The merits of new-technology large motors
by Lock Hughes <[EMAIL PROTECTED]>
5) RE: Myers motors update
by jerry dycus <[EMAIL PROTECTED]>
6) Re: Extra TAX on High-Milage Hybrids ?? WHAT !!
by Victor Tikhonov <[EMAIL PROTECTED]>
7) Re: what about battery swapping ? was: Look at fast charging from the
other end of the plug
by Doug Weathers <[EMAIL PROTECTED]>
8) RE: The merits of new-technology large motors
by "Phil Marino" <[EMAIL PROTECTED]>
9) Re: Zinc-Air "refueling" - was: Re: what about battery swapping ? was:
Look at fast charging from the other end of the plug
by Doug Weathers <[EMAIL PROTECTED]>
10) NAPA Floddies
by "Michaela Merz" <[EMAIL PROTECTED]>
11) Re: Low rolling resistance tires
by Ricky Suiter <[EMAIL PROTECTED]>
12) RE: Myers motors update ...whats wrong with a sparrow
by "John G. Lussmyer" <[EMAIL PROTECTED]>
13) Re: NAPA Floddies
by "Roland Wiench" <[EMAIL PROTECTED]>
--- Begin Message ---
has it occured to anyone that maybe the NmG is a rebadged Sparrow???
Madman
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: "EV Discussion List" <[email protected]>
Sent: Thursday, November 24, 2005 6:28 AM
Subject: Re: Myers motors update
> <<<<
> The company calculates that a driver charged 11 cents
> per kilowatt
> will pay about 55 cents for the "fill up" that powers
> the NmG about
> 30 miles.
> The pollution-free NmG can be fully recharged in 4 to
> 6 hours using a
> 110-volt outlet and less than half that time using a
> 220-volt outlet.
>
> Priced at $35,000, the NmG comes in dazzling exterior
> colors.
> >>>>
>
> 6mi/kwh for a one-seater isn't really that efficient, is it? If I run the
Ranger
> at 45mph on the level, it would give >4mi/kwh.
>
> I hope Jerry's 3-wheeler is less than half that price and not nearly as
> goofy-looking - at least in yellow, it still looks like a duck...
>
--- End Message ---
--- Begin Message ---
Mike and those considering Gel batteries,
My friend Carlo in Germany is now at over 80,000 km (nearly 50,000 miles)on a
set of 14 6V 160 A-Hr golf cart size Gel batteries from Varta in his Skoda
electric hatchback.
He uses no regulators or block by block equalization equipment, just a
temperature compensated charger set to the correct lower voltage for a gel
pack. Other than selecting a suitable charger, his setup is as simple as
flooded GC batteries, without the maintenance or mess. Gentle driving and a
careful deep discharge every month or so to maintain capacity helped them give
their long life, according to Carlo.
Let's give a round of applause for Gel batteries! (Led by someone who spent
way too much money on TS lithium ion cells that do not last as long and require
special BMS modules. However, light weight and longer range are still
important considerations.)
Best Regards,
Doug
>
> From: M Bianchi <[EMAIL PROTECTED]>
> Date: 2005/11/27 Sun AM 11:01:16 EST
> To: [email protected]
> Subject: Re: Question about MK battery AGMs and Gel cells
>
Snipped
>
> I have long argued that having block-by-block continuous equalization of a
> pack
> will pay off, and now I claim to have the evidence. 13 blocks, 10 years,
> 23,000 miles.
>
but the bottom line is that a good, intelligent, block-by-block
> equalizing charger is essential to having an electric car that delivers long
> battery life and is not an on-going maintenance chore.
>
> --
> Mike Bianchi
>
--- End Message ---
--- Begin Message ---
On 26 Nov 2005 at 19:10, David Roden wrote:
> They definitely aren't shy about wearing their religion on their sleeves,
> but I don't see anything on the site that says "God told them to overprice
> this stuff." Can you provide a URL? ;-)
No, but I can refer you to a good book. THE Good Book, actually. But I
digress...
Guys & gals, let's keep the topics EV related and stay clear of comments
relating to
religion or politics, topics that are guaranteed to beget flame wars.
Clyde R. Visser, P.E.
List creator, admin, chief cook, bottle washer, conservative Republican, &
Christian
(not necessarily in that order)
--- End Message ---
--- Begin Message ---
This is an old article from February 2001.
In my own efforts to understand EVerything, it appears that this
article makes some good points pro and con for DC vs AC and brushed vs
brushless.
I'm only hoping that knowledgeable folks here might comment if they see
anything that's perhaps dated now.
Thanks
Lock Hughes
http://autos.groups.yahoo.com/group/TorontoEVA/
The merits of new-technology large motors
Technical advances give Large Brushless Drive Systems significant
advantages over conventional DC or AC induction motors, as Ed Lee
describes in this article
Brush DC motors have been the most prominent variable speed technology
since the DC motor was invented (1) by Werner Von Siemens in the late
1800s. It revolutionized variable speed control of industrial machines.
The AC induction motor came much later in 1924 invented by Nicolas
Tesla.
In 1962 two engineers, T.G Wilson and P.H Trickey published a paper (2)
in which they described a "brushless DC" motor.
Magnet and power switching device technology prevented this invention
from becoming a practical general purpose drive technology until the
late 1980s when Powertec Industrial Corporation started manufacturing
general purpose brushless systems at prices competitive with brush DC
systems.
AC drives were beginning to see widespread use during this time as
well, since power bridge technology was allowing inverter drives to
make AC induction systems a practical alternative to DC in some
applications.
AC inverters did not provide good torque control or smooth speed
control, however, and could not be used in many applications.
By 1993, AC inverters developed into "vector" technology that gave the
vector inverter the ability to use an AC induction motor to provide
independent torque and speed control similar to DC and Brushless DC,
but using an AC induction motor.
A war has been raging ever since between the three technologies, a war
that has benefited the industrial consumer.
The prices of DC systems has remained at 1980 levels in spite of
inflation while the price of brushless and AC vector systems has
dropped to the point that all three technologies are close to the same
pricing (with exceptions being at the size extremes).
Brush DC systems have reached the pinnacle of their design, with better
motors, brushes, frame configurations, and drives with software control
providing the best possible performance and reliability.
AC induction motor systems have advanced to solving most of the
standard induction motor problems running on the most modern AC vector
drive designs with high speed IGBTs (Insulated Gate Bipolar
Transistors) and advanced control algorithms.
Brushless drive systems have also gained ground with better magnets and
much improved drive controls (3).
Today's brushless drive systems include motors made with the robust 3rd
generation Neodymium-Iron-Boron magnet materials that have much better
thermal characteristics and high magnetic strength.
With today's corona-resistance magnet wire insulation and these
improved magnets and the exceptional performance of a modern brushless
drive, the industrial consumer has available a drive system capable of
the roughest application that will also provide high accuracy
performance at competitive prices.
Applications where brushless drives are being used today include those
not typically requiring very high performance drives, but requiring
tough, dependable, continuous duty operation.
A significant number of applications on extruders, wire drawers,
winders, cranes, cable tensioners, conveyors, pullers, printing
presses, roll formers, and other traditional "tough" applications are
being done with brushless drives from the major drive system
manufacturers.
Why Brushless?
What is the reason machinery manufacturers and users choose brushless
over the time-proven DC drive or the now widely accepted vector
induction drive/motor systems?
1- Performance: Brushless systems offer the highest available dynamic
accuracy of any of the three major types of drive systems.
Dynamic accuracy results in consistent and repeatable machine
performance creating less product variation resulting in higher quality
product and higher production rates.
Extensive tests were performed on a blow-molding machine of Brush DC
versus Brushless and a clear advantage was shown in production
performance from the brushless drive system (4).
2 - Size: brushless motors are the smallest available motors for a
given power rating.
The small size fits the requirements for smaller machines taking up
less plant floor space, and the lighter weight results in lower
shipping cost, easier handling, and lighter machine structure to
support the motor, which is usually a substantial part of the mass in
many machines (3).
3 - Efficiency: The brushless motor is the most efficient motor
technology available today for an industrial application.
This means less heat to get out of the machine, less heat into the
manufacturing area, and lower power consumption.
Brushless system efficiencies are typically 2 to 3 percentage points
higher than induction vector systems and greater than this against
brush DC.
3 Formal tests were conducted by Ontario Hydro (Canada) in a
before/after comparison of a machine conversion from brush DC to
Brushless DC, in which efficiency improved 13% minimum, and a whopping
78% at 25% speed (7).
4 - Bearing Stress: Unlike AC induction motors 6, particularly large
motors 50 or more hp, brushless motors with surface-mounted magnets
have very large air gaps and therefore very low stator-rotor capacitive
currents.
Large AC motors have substantial difficulty (5) with bearing damage due
to current flow from the rotor through the bearing.
Additionally, both brush DC and AC induction motors create very high
heat levels in the rotor and much of this heat must be conducted
through the shaft and bearings to the stator before being removed by
the ambient air.
Brushless motors produce very little rotor heating because there is no
electrical current (other than minor eddy-current loss) and no slip in
the permanent magnet rotor.
Advancements in magnet technology (reducing cost of magnets), combined
with smaller physical size, results in today's brushless motors being
less costly to make.
The proliferation of PWM type drives and improvements in manufacturing
procedures and economies of scale has created a high performance drive
control that costs much less to make than in years past.
This means brushless systems do not necessarily cost more.
In fact, brushless systems may even be less costly that either of the
other two primary variable-speed drive technologies in the 20 to 200 hp
range.
Brush DC drives still have the cost advantage in the above-200 hp range
due to the simple elegance of the controller using SCRs rather than the
more costly IGBTs used by both induction vector and brushless.
Motors smaller than 20 hp are made in very high volumes and the
induction vector systems, as well as brush DC have the cost advantage
in those smaller sizes, where the smaller brushless motor is not enough
smaller to make up for the magnet cost.
Who makes large brushless drives today?
Any induction vector drive has the basic power system to run a
brushless motor, but brushless motors must be shaft-position commutated
and require a different control algorithm (software) than the induction
motor.
It is relatively easy to make a standard vector drive run a brushless
motor by having a menu choice that selects this different algorithm.
With most manufacturers, their standard drive will run brushless as a
menu choice, or EPROM change.
Therefore, virtually all major drive manufacturers make drives today
that run PM brushless motors and unlike 10 years ago, there are several
manufacturers of large PM brushless motors to choose from.
Summary: Given that efficiency, size, and low maintenance are key
issues in drive system selection, brushless motors and drives have
enjoyed a growth of use in heretofore "standard" applications where
performance at all costs has not been an issue.
California's energy woes will spread to other areas in time.
The nation's energy costs will continue to rise, stressing all parts of
our economy and that stress will continue to push high efficiency ASD
systems to the front.
References (1) Siemens Corporate Brochure (2) T.G.
Wilson, P.H.
Trickey, "DC Machine with Solid State Commutation", AIEE paper #
CP62-1372, Oct 7, 1962 (3) Dan Jones "Very Large Brushless DC Motors in
Industrial Applications", Incremotion Associates, Thousand Oaks, CA (4)
Test results, Owens-Brockway Corp, results available from Powertec
Industrial Motors, Fax 803-328-1870 (5) Thomas Lipo, Donald Novotny,
"Circulating Type Motor Bearing Current in Inverter Drives", IEEE
Journal # 0-7803-3544 9/96, Sep 1996 (6) Richard Nailen, P.E., "Are
ASDs More Trouble Than They're Worth?", Electrical Apparatus, November
1996 (7) Power Study commissioned by Ontario Hydro to third party
testing lab, Ortech International Energy Technologies, 1994.
Copies available from Powertec Industrial Motors Fax 803-329-1870 About
the author: Edward Lee earned a BSEE from NC State University in 1995
and has worked in all areas of the adjustable speed drive business.
He has designed brush DC and AC induction drives and assisted in the
design of brushless DC drives.
Mr.Lee has published several papers on the subject of brushless system
design and application.
He is currently employed as General Manager and VP Sales of Powertec
Industrial Motors in Rock Hill SC, which makes brushless motors and
drives 1/2 to 400 hp.
Original URL here:
http://www.engineeringtalk.com/news/poc/poc100.html
__________________________________________________________
Find your next car at http://autos.yahoo.ca
--- End Message ---
--- Begin Message ---
Hi Jody and All,
"Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]> wrote: You have to put
some of that stuff into context though - who would need to
replace a swingarm?
Their original swing arm made it really hard to replace the belt
which is a common problem on them, misadjusted as they had no adjustments.
But $1900+ is rather high. I built mine from new parts for under
$100 on the E woody.
For the Freedom EV it will be a little more pricy, about $300
which would be a selling price of $450-500. My whole swing arm system, twin
motors, brake, belt drive will be under $1800 with more torque and endurance
than the Sparrow/NmG's.
Rich, most know the NmG is a rebadged Sparrow though they have
done some good improvements for reliability. Not worth the $35k though by any
means.
They are not the easiest things to manufacture.
Yes they are !! Just a tube, bearing, spindle and brake assembly..
As easy as the front brake assembly.
The
brakes are definately too expensive though.
Actually at $409 for the full assembly, not that bad, probably 2x's
cost in their low production and what the swing arm should have cost..
I would have thought that if
you were building a car like that you would use ready off the shelf parts so
someone could go to a regular auto parts store for brake and suspension
parts.
That's what I'm trying to do.
HTH's,
Jerry dycus
-----Original Message-----
From: jerry dycus [mailto:[EMAIL PROTECTED]
Sent: Saturday, November 26, 2005 11:16 AM
To: [email protected]
Subject: Re: Myers motors update
Hi Rod and All,
Look under sevice. Check out the price for the rear
swing arm, $1900+ !! I'd have a hard time keeping a straight face charging
$500 for that assembly !!
If you look under values, you'll find that apparently
God told them to overprice this stuff !!
Rod Hower wrote:
I looked all over and could not find pricing, just a
page that said 'contact Myers Motors'.
Where did you find prices?
Rod
--- Roderick Wilde wrote:
> If you think the price for the vehicle is high go to
> the service section to
> see what it will cost you for new brake pads.
> http://www.myersmotors.com/index.html It appears
> they only come with the
> spindle, hub, disc, and caliper assembly. At least
> that is the impression
> you are left with.
>
> Roderick Wilde
>
>
> ----- Original Message -----
> From: "Shawn Rutledge"
> To:
> Sent: Thursday, November 24, 2005 11:00 AM
> Subject: Re: Myers motors update
>
>
> > On 11/24/05, Ken Trough
> wrote:
> >> > Myers Motors Unveils
> >> > the NmG (No More Gas) Electric Vehicle
> >>
> >> I'm very glad that a freeway capable EV is being
> produced domestically,
> >> but they should have hired a marketing firm to
> come up with a good name
> >> for the product. I think that name choice is as
> weird as the body of the
> >> car.
> >
> > Yeah no kidding. What was wrong with Sparrow?
> Back in 2000 or so I
> > actually knew a girl who wanted one, and she
> wasn't even very weird.
> > Goes to show they had marketing figured out, at
> least.
> >
> > But at this price we can just pretend it doesn't
> exist, like everyone
> > else is going to do.
> >
---------------------------------
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--- End Message ---
--- Begin Message ---
Dewey, Jody R ATC (CVN75 IM3) wrote:
How would they compute it? I would think that an odometer check and a
vehicle weight calculation would be more fair than a gas tax.
Very easy, CA already proposed this - a cheap GPS mandated just the same
way as seat belt or CA converter. It doesn't track where you go, so
privacy advocates are satisfied, just how many miles.
Data read at the pump at the time of fueling and the tax computed
on the fly as you pump.
You pay extra per weight at the time of yearly registration,
few weight classes will take care of that. Obviously 8 ton truck
does more damage in 100 miles than a rabbit in the same distance.
It sure not truck driver's fault that he must drive it to get his
job done, but someone still *has* to pay for *his truck's* damage,
so why should it be Rabbit driver?
Bottom line - everyone must pay for the degree of damage they do;
no less no more. If we all reduce tax, great for pocketbooks,
but we will have no roads. So we must do it, but efficiently and fair.
Businesses pay for their fleet use. Individuals discouraged
to buy heavy vehicles or if they still want to - pay accordingly.
If you complain you must commute far (as that student in recent
article) - sorry, tough luck. Why should *I* pay because *you*
choose to live so far away that commute 500 miles per day??
Can't afford so much gas - move closer! Isn't it obvious?
Of course there will be separate tariff for commercial trucks,
city buses, etc, as always bunch of adjustments and exceptions,
but you get the general idea. Technical implementation is not
difficult. It's all in big interests groups hands (read - *not*
going to be fair) so if ever materialize, it will be after some
critical mass runs out of patience or circumstances force it.
Unfortunately not because of common sense now.
Victor
--
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Hi Mark,
You did a good job addressing the points I raised about battery
swapping. Of course all of these issues can be solved or worked
around. My central thesis, which I didn't do a very good job of
articulating, is this:
"Battery swapping, because of the additional complexities it
introduces, will add costs at both ends of the charging cable. Both
the vehicle and the recharging infrastructure will become more
expensive, perhaps to the point of making this technology economically
unviable when compared to competing approaches."
We can certainly design a modular battery swapping system that works
(see for example forklifts). I just see more problems with battery
swapping that with competing technologies, such as advanced batteries
and fast charging. Such as:
- chicken-and-egg problem (infrastructure needs to be in place before
the vehicles will be useful)
- screwy economics of storing and moving electrons from place to place
inside thousand-dollar boxes
I just can't see how to get from where we are to the future where we're
all swapping battery packs. I can't imagine a business plan that
doesn't require an enormous up-front investment. And we've seen that
the companies with the dollars to burn aren't very interested in
getting production EVs on the road.
For whatever reasons, the massive effort to develop the infrastructure
and the EV in parallel has failed in the USA. What's working?
Hybrids. They are an incremental step away from the ICE and towards
the EV. The next step I expect to succeed is the plug-in hybrid. From
there, I expect to see the market start emphasizing the batteries and
de-emphasizing fossil fuels. Slowly, the ICE will begin to disappear,
first from short range vehicles. Eventually it will only be used on
long-range vehicles and trucks. Nowhere in this smooth transition do I
see a place for battery swapping. I'm not saying it's impossible, mind
you, just that this kind of abrupt paradigm shift hasn't yet worked.
I'm not a business owner or any kind of student of economics, so I
don't know how to judge if these basically economic problems are
solvable. Does anyone on the list have a more informed opinion? Or
some examples of analogous situations that work out economically?
The rest of this message discusses Mark's points individually and goes
on for a while. You may want to skip it.
On Nov 25, 2005, at 3:28 PM, Mark Fowler wrote:
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Doug Weathers
- who owns the pack?
Whoever you decide to lease it from - car mfr, rental company,
whatever.
Not you.
Leasing leads to the possibility that the packs can be recalled,
orphaning a bunch of cars. If the cars are also leased, then we end up
in the same place as the users of the EV1 ended up. Chicken-and-egg
problem: EVs with modular packs will be more expensive, making them
less popular. Swap stations won't be economically viable until there
are enough customers on the road.
- who is responsible for taking good care of it?
The user.
This pack will be worth a couple of thousand dollars - there will be a
small micro onboard logging things like deep discharges, high currents,
overcharges, and any other battricidal events.
You will pay a penalty rate for the bad things you do to the battery.
(The onboard micro will talk to your controller and charger and let
them
know the appropriate limits.)
This requires the onboard charger and controller have a standard
interface and API to talk to each other. New chargers and controllers
will need to be developed, and the standards will need to be developed
too. Some of the standards development work is going on right now on
the EVTECH list (EViLBus discussions), but it's a long way from being
finished, and even farther from being implemented.
It's important that the user understand the ramifications of battery
abuse. Unless the vehicle can prevent damage to the modules, we'll end
up with unhappy people who didn't know they'd get slapped with a huge
bill for running the pack to 0% SoC, and with unscrupulous people who
claim they didn't know.
Further complications arise when we start talking about swapping out
more than one battery module, to provide greater flexibility in vehicle
design. Now the car needs to have an internal discussion between all
the modules and the controller to decide what's safe. On the other
hand, if the car can be configured to pull varying amounts of current
from the different battery modules, you end up with a great way to do
hybrid packs. If you have, say, four battery bays in your EV, you can
choose from various combinations of high-capacity and
high-discharge-rate modules to tailor your pack for today's driving
tasks. Tomorrow you can choose differently.
- how much infrastructure will be needed? Lead ain't light.
Your local battery swap centre will use small forklifts to remove and
replace your standard sized pack from (one of) the standard battery
position(s) in your car.
I don't know about you, but I'd be nervous seeing a bored attendant on
a forklift driving several tons of mass towards my beautiful car. Are
my fears unfounded? Am I slandering both forklift drivers and service
station attendants?
I imagine that forklifts that get their batteries routinely swapped
pick up a certain amount of wear and tear from the process. Nobody
cares, since it's not important what they look like as they run around
inside a warehouse. However, the way a car looks on the street is of
much greater importance. I certainly wouldn't enjoy driving a car
that's as beat-up as the average forklift.
Am I slandering the average forklift?
They will have test, recharge and storage facilities on site.
Ah yes, test facilities. How often do the packs get tested? Testing
would presumably involve a discharge test. How would you deal with the
pack energy? Burn it off as heat, put it back into the grid, put it
into other packs that need charging? Would the customer know if the
pack was recently tested? Would she be able to ask for packs that have
just been tested to ensure her vehicle will have the range needed?
- how many battery packs will we need? Probably more than one per EV.
Isn't this wasteful?
Depends on how quickly they can charge depleted packs. (See lithium
nanothingy discussion)
If the packs can be recharged quickly enough, we don't need to swap the
modules. The longer it takes, the more packs we need lying around
taking up space and capital.
Depends on how long a typical pack lasts between swaps.
Depends on when customers come to get batts swapped (eg rush/peak hour)
One scenario:
The pack provides a day's worth of typical driving.
It can be fully recharged in 1 hour.
They can charge any number of batteries at once.
All customers visit the swap centre spread evenly over a 4 hour window.
The battery swap is instantaneous.
(Yes, some of these are completely BS)
Anyway, the swap centre will need to have enough charged packs on hand
to provide for all the customers in the first hour.
However, the final three hours of customers can be served with the
recharged packs of the customers earlier in the day.
The depleted packs from the final hour go into storage overnight (after
being charged) ready for the first hour of customers the next day.
In this scenario, there needs to be only 25% more packs than customers.
Not really that wasteful.
Your numbers sound reasonable, but I don't think that a 25% increase in
the number of packs is negligible.
Given that the pack in my EV is the second most expensive component
(and that it has a limited lifespan) adding 25% to the cost of battery
packs seems like a terrible idea.
- how can you tell if you just got a good pack or a bad one?
The onboard micro keeps track of the Ah capacity and V sag under load.
Once these get below set limits, the battery is marked "bad" and is
sent
off for recycling.
You will always get a pack that is "good enough".
Does the user know this? Will the user get used to having a certain
amount of range, but then get a marginal pack one day and end up
stranded? The problem of determining the remaining range in your pack
is a very hard one. Can we do it well enough to make the driving
experience consistent across all of the packs that will be in service?
- how many battery pack standards will there be? One for each
manufacturer, as with power tools? (Philippe sees this problem too.)
Depends if govts get involved and mandate a standard (not likely, I
know).
Mfrs MIGHT set a standard themselves, like CDs and DVDs.
(Then again, they will probably come up with multiples: DVD+R, DVD-R,
HD-DVD, BluRay, etc)
The swap centres will just arrange themselves to handle the multiple
standards.
I suppose that's doable, analogous to the different types of liquid
fuels available in today's filling stations. I don't see anyone
spending any money on infrastructure until there's an agreed-upon
standard.
- how will you upgrade your car to new battery technologies? If we
make lead-acid batteries the standard, how long will we be stuck with
them?
This is the good part with swappable battery packs.
When something better comes along, there's no technical reason why you
couldn't start using it straight away.
The onboard micro would let your controller and charger know the max
and
min voltage, the max current draw etc.
This requires controllers and chargers and instruments to be quite
flexible. Nice idea, but again it adds cost.
- what if you want an EV with more range or more performance than a
multiple of standard modules can provide?
There would be two or three different sizes available.
Eg small, medium and large.
You could design a small car that takes a large pack (or two small
packs).
- how about the guy who buys an old cruddy pack cheap, then swaps it
at
the filling station for a nice new one, then sells the new one? What
if this guy runs the filling station?
Customers don't own the packs.
The swap stations only accept "their" packs to swap.
Whoa, there goes the main reason for doing battery swapping -
long-distance driving. I thought the idea was to be able to drive your
EV until you need a pack swap, then drive into the nearest swap center
and get a new pack. If you can only swap at XYZ's swap center, then
the infrastructure requirements just exploded. XYZ needs swap centers
all throughout my driving range.
We may end up with "peering agreements" between the various module
owner companies. Say for example XYZ and ABC agree to accept each
other's modules. I'd expect the user to have to pay a premium to drop
off his XYZ pack at an ABC center, and then pay another premium when
he's going the other direction. I'd also expect to find that DEF Corp.
refuses to take either, the way you sometimes find a cash machine that
can't reach your bank account.
More annoyances.
The unique ID in the onboard micro makes it fairly easy to keep track
of
who has their packs.
...
To solve the pack ownership problem we'd need:
- much better determination of state-of-charge and state-of-health of
a
battery pack (I want this right now!)
You can get this right now.
There are simple regulators (Rich Rudman's that tell the PFC charger to
back off).
There are smarter regulators (Metricmind.com and EVBMS Yahoo list) that
report voltage of each cell.
An Emeter will keep track of state of charge.
All you really need to do is add some brains and memory that keep track
of these things over time, and you have a pretty good picture of where
this battery pack is in its overall "life"
- a way to track each pack with this information, in a way that can't
realistically be tampered with
Onboard micro.
Perfect tamper-proofing is practically impossible.
"Good enough" tamper-proofing is reasonably easy.
- a financial model to charge or credit users for the difference
between the SoC/SoH of the pack they're trading for the pack they're
getting
Compared to the cost of the battery, the cost of the charge is so
insignificantly tiny that it can be safely ignored.
SoH only really comes into it if the customers keep the batteries for
months on end, charging them at home, and swapping them only when
travelling long distances.
Unless the pack was on the edge of failure, and dies in my EV when I
drive it away from the swap center. Can this be prevented well enough
to make it rare enough to not worry about? (Probably it can.)
Once again, the onboard micro tracks the use of the battery while in
the
customers care.
It will be something along the lines of Ah throughput - X dollars per
1000 Ah.
- a method to track users who put unusual amounts of wear on their
packs, so they can be billed. (What happens when someone unknowingly
murders a pack and then gets slapped with a $1000 fee for one fillup?
What happens when someone knowingly murders a pack and then acts like
he's ignorant?)
A corollary to using an onboard micro to track this stuff is to have it
talk to the customer's controller and charger and let them know the
appropriate limits.
The customer won't be able to overcharge, overdischarge or overcurrent
the pack.
Their controller and charger won't let them.
(see above for penalty rates for exceeding the set limits)
See above for the need for a standards development process to create
the protocols by which these components talk to each other. To be
fair, fast charging will also need some standards, although perhaps not
as many.
Of course, this system is for the general public, with enough of a
safety net built in to stop ignorance of the underlying processes from
costing anyone a lot of money.
It's not for the drag racers.
It's not for the do-it-yourself-as-cheap-as-possible crowd.
It's for the John and Mary Average, who are used to driving a car until
it is almost empty of fuel, then filling it up within a few minutes.
This market would also be served with a fast charging solution. Or, it
could possibly be educated away from the
"five-minute-refuel-every-week" model over to the
"several-hour-refuel-every-night" model, especially with advanced
batteries that provide the range that John and Mary require.
I consider myself a John. I'm only converting an EV because I can't
buy the one I want for the amount I can pay.
Mark
--
Doug Weathers
Bend, OR, USA
http://learn-something.blogsite.org
--- End Message ---
--- Begin Message ---
From: Lock Hughes <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: The merits of new-technology large motors
Date: Sun, 27 Nov 2005 13:54:29 -0500 (EST)
This is an old article from February 2001.
In my own efforts to understand EVerything, it appears that this
article makes some good points pro and con for DC vs AC and brushed vs
brushless.
I'm only hoping that knowledgeable folks here might comment if they see
anything that's perhaps dated now.
Thanks
Lock Hughes
http://autos.groups.yahoo.com/group/TorontoEVA/
The merits of new-technology large motors
Technical advances give Large Brushless Drive Systems significant
advantages over conventional DC or AC induction motors, as Ed Lee
describes in this article
.
.
.
.
Additionally, both brush DC and AC induction motors create very high
heat levels in the rotor and much of this heat must be conducted
through the shaft and bearings to the stator before being removed by
the ambient air.
This last claim is hokum. At least in the brushed DC motors we are familiar
with ( eg. ADC) the heat flow "through the bearings" is probably close to
zero. The motor is primarily cooled by air flowing between the armature
and the stator. So, the temperatures of the stator and rotor are similar.
And, the thermal resistance of the shaft itself, not to mention the very
high thermal resistance throught be bearing balls ( that have miniscule
contact area with the races) would prevent any real heat flow through the
shaft and bearings - even if the armature were much hotter than the stator.
It's hard to imagine a motor so poorly designed that significant heat would
flow through the bearings.
We should take all of these claims with a bucket of salt. The last sentence
below says it all.
Phil
References (1) Siemens Corporate Brochure (2) T.G.
Wilson, P.H.
Trickey, "DC Machine with Solid State Commutation", AIEE paper #
CP62-1372, Oct 7, 1962 (3) Dan Jones "Very Large Brushless DC Motors in
Industrial Applications", Incremotion Associates, Thousand Oaks, CA (4)
Test results, Owens-Brockway Corp, results available from Powertec
Industrial Motors, Fax 803-328-1870 (5) Thomas Lipo, Donald Novotny,
"Circulating Type Motor Bearing Current in Inverter Drives", IEEE
Journal # 0-7803-3544 9/96, Sep 1996 (6) Richard Nailen, P.E., "Are
ASDs More Trouble Than They're Worth?", Electrical Apparatus, November
1996 (7) Power Study commissioned by Ontario Hydro to third party
testing lab, Ortech International Energy Technologies, 1994.
Copies available from Powertec Industrial Motors Fax 803-329-1870 About
the author: Edward Lee earned a BSEE from NC State University in 1995
and has worked in all areas of the adjustable speed drive business.
He has designed brush DC and AC induction drives and assisted in the
design of brushless DC drives.
Mr.Lee has published several papers on the subject of brushless system
design and application.
He is currently employed as General Manager and VP Sales of Powertec
Industrial Motors in Rock Hill SC, which makes brushless motors and
drives 1/2 to 400 hp.
__________________________________________________________
Find your next car at http://autos.yahoo.ca
_________________________________________________________________
Is your PC infected? Get a FREE online computer virus scan from McAfee®
Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
--- End Message ---
--- Begin Message ---
On Nov 26, 2005, at 4:57 PM, toltec wrote:
Even if we manage to do solve these problems, we'd still have to
develop a pack-swapping infrastructure.
instead of pack-swapping, a much better solution would be investing
the capital on zinc-air "refueling" stations...
There are other similar systems, like the ones that use chemical
reactions to liberate hydrogen from fuel pellets. Here's one:
<http://www.millenniumcell.com/>
just as fast as swapping, with far less problems
I wouldn't say fewer problems, just different problems.
(zinc-air is a primary battery chemistry - it needs to be mechanically
"recharged")... given that zinc-based chemistries are environmentally
benign and there aren't serious resource limitations, and that
zinc-air recharging systems alredy exist (in prototype, at least), and
that zinc-air has a decent power-density, and that the "refueling"
system )ie: a driver can plug the gose into the car to remove the
spent zinc pellets and load in new ones, etc) is self-servable, etc,
it makes a lot of sense...
It requires the creation of an infrastructure, though. Your car can't
move unless you have a source of the pellets. By contrast, a
battery-swap EV would potentially be able to be charged at home or
anywhere there's an outlet. A battery-swap EV would be able to move
even without a bunch of battery swap stations being available.
Then there's the environmental impact of mining the zinc, refining the
spent fuel, etc. There will be many other issues.
strangely enough, the most cogent agrument I've heard against zinc-air
"recharging/refueling" systems is that "they don't exist yet" which,
in some minds, apparently, seems to be the ultimate damnation...
My argument is not "they don't exist" but rather "I can't figure out an
economic model to bring them into existence."
in any case, it seems to be a far more practical and realistic
solution than pack-swapping, since it avoids almost all of the
downsides of pack-swapping (except for the capitalization and adoption
requirements)
Which I propose as being the main problem. There's some critical mass
of infrastructure that must be in place before it begins to generate a
profit. We can argue about how much money is required (personally I
don't have a clue), but it's not going to be chicken feed.
--
Doug Weathers
Bend, OR, USA
http://learn-something.blogsite.org
--- End Message ---
--- Begin Message ---
Hello everybody:
We had to replace a set of 6V floodies recently and, because TROJAN was
not able to get us some T125s with posts (AP)m we went ahead an purchased
some NAPA deep cycle 6 Volts. Those folks at the NAPA store didn't know
too much about their batteries but it looked as if those floodies (made by
Exide) would have equivalent ratings. They made me a good deal and off we
went.
However .. I am kind of not happy with those batteries as they seem to not
perform as well as I am used to with Trojans. First, they react very badly
to even the slightest drop in temperatures. Second: The drop in voltage is
significant (to about 108 V at 300 Amps, 120 V nominal) when fully
charged.
I went back to NAPAs website to re-check the data on those batteries. It
says, they have a reserve capacity of about 100 minutes. How would I have
to compare that to, say, Trojans? Isn't the reserve capacity the discharge
at 20 Amps? I can't quiet believe that as the T-105 has a capacity of 447
Minutes @ 25A?
So .. any input would be welcome.
Michaela
--- End Message ---
--- Begin Message ---
Remember, you need 0 offset so if any of these wheels in fact have any offset
you'll need a spacer equal to the offset to cancel it out. But like was
mentioned some spacer bolts would work in this case since the bolt pattern is
the same.
Lawrence Rhodes <[EMAIL PROTECTED]> wrote: Of these which have 14" tire size.
>
GM L-body
Buick Skyhawk '75-'81
Chevrolet Vega, Monza '71-'81
Pontiac Sunbird, Astre '76-'81
Oldsmobile Starfire '75-'81
If they are these might be the ones. . LR...........
----- Original Message -----
From: "Stefan Peters"
To:
Sent: Saturday, November 26, 2005 10:49 AM
Subject: Re: Low rolling resistance tires
> > OK so the GEM is the same as the Th!nk but what standard bolt pattern
> fits. Honda, Toyota or ???? Thanks for the info. LR......
>
> 4 on 4" (101.6 mm)
>
> Austin-Healey Sprite
> Crosley - all '39-'52
> MG Midget
> Jensen Healey
> Opel Manta, Kadette, GT
> GM L-body
> Buick Skyhawk '75-'81
> Chevrolet Vega, Monza '71-'81
> Pontiac Sunbird, Astre '76-'81
> Oldsmobile Starfire '75-'81
>
> I believe 76-80 Honda Accords also have this pattern at a +20mm offset
>
> Given that info, an adapter might be an easier find :)
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
At 09:05 AM 11/26/2005, Jeff Shanab wrote:
I had the opertunity to sit in a sparrow not to long ago and up to that
point I had wanted one. Unfortunantly they are not for all sizes of
people! The size of the cabin kinda got to me. I am only about 5'4" but
heavy. As I sat in it I found my head was a mere inch from the roof and
i was looking thru the top edge of the windshield. The side walls taper
in and the feeling is rather clasutrophobic; I wonder if they ever
thought of a "convertable" a wind screen and an open cockpit :-)
I'm 6' tall, and just fit in a Sparrow (about 1" headroom). Yes, it
is a bit cramped feeling, but also I'm not getting Rained on! (I
compare the Sparrow to a motorcycle, as that is what it replaces for me.)
Anyway, just my 2 cents, I hope they make the merlin they used to have
on there site.
I thought the Merlin's were a bad joke. No roof means that it can't
be used about 80% of the time out here. I'd also bet that many
states would require you to wear a helmet in it as well.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
Hello Michaela,
Buying a battery, it is best to convert the reserved minutes for the ampere
your EV runs at to calculated the ampere hour.
For Example, the T105's have a rating of 447 reserve capacity at 25 amps. 115
minutes at 75 amps. Can deliver 12.25 amperes for 20 hours (12.25 ampere x 20)=
225 amp-hrs.)
Actually when the battery capacity decreases as the discharge current
increases.
'
The T105 may only deliver 20 amps for 9 hours or 9 x 20 = 180 amp.hr.
At 75 amps is 115 minutes or 1.9 hrs x 75 amp = 142.5 amp.hr.
For this reason, it is difficult to compare the rated ampere-hour capcity with
reserve capacity.
If we convert the 447 minutes to amp.hr. we get 447 min. / 60 - 7.45 hrs.
7.45 hrs x 25 amps = 149 amp-hrs.
So when the current increases the reserve minutes decreases as well as the
amp-hr. decreases.
The Trojan plates are thicker which holds more acid deep inside the plates. As
each surface layer discharges, more acid comes to the surface. If you note
when you shut down your EV, the voltage will be at at 12 volts per 12 volt
battery. Let it set for awhile and you will note the voltage will come up a
bit to 12.1 to 12.3 volts. This is call battery defusing time, where the
charge depth inside the plates have come to the surface of the plates.
One time I missed my distance back home by 1/2 mile. I just let the EV set for
about 15 minutes and I was able to roll home at about 5 mph.
Roland
----- Original Message -----
From: Michaela Merz<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Sunday, November 27, 2005 2:04 PM
Subject: NAPA Floddies
Hello everybody:
We had to replace a set of 6V floodies recently and, because TROJAN was
not able to get us some T125s with posts (AP)m we went ahead an purchased
some NAPA deep cycle 6 Volts. Those folks at the NAPA store didn't know
too much about their batteries but it looked as if those floodies (made by
Exide) would have equivalent ratings. They made me a good deal and off we
went.
However .. I am kind of not happy with those batteries as they seem to not
perform as well as I am used to with Trojans. First, they react very badly
to even the slightest drop in temperatures. Second: The drop in voltage is
significant (to about 108 V at 300 Amps, 120 V nominal) when fully
charged.
I went back to NAPAs website to re-check the data on those batteries. It
says, they have a reserve capacity of about 100 minutes. How would I have
to compare that to, say, Trojans? Isn't the reserve capacity the discharge
at 20 Amps? I can't quiet believe that as the T-105 has a capacity of 447
Minutes @ 25A?
So .. any input would be welcome.
Michaela
--- End Message ---
