EV Digest 6952
Topics covered in this issue include:
1) Re: Cheap "balancer" for A123 pack
by "Shaun Williams" <[EMAIL PROTECTED]>
2) =?iso-8859-1?Q?Re:_Cheap_=22balancer=22_for_A123_pack?=
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
3) Re: VOLTS vs AMPS & RE: Make It - Enough!
by "Phil Marino" <[EMAIL PROTECTED]>
4) Re: firefly batteries?
by Frank John <[EMAIL PROTECTED]>
5) Re: DC/AC converter (EV to Grid/Home)
by Jeff Shanab <[EMAIL PROTECTED]>
6) Re: DC/AC converter (EV to Grid/Home)
by "Zeke Yewdall" <[EMAIL PROTECTED]>
7) Re: An Ebay find?
by Jeff Major <[EMAIL PROTECTED]>
8) Re: DC/AC converter (EV to Grid/Home)
by Jeff Shanab <[EMAIL PROTECTED]>
9) Re: vroombox and EV ?
by "Bob Rice" <[EMAIL PROTECTED]>
10) RE: Electrical/Mechanical Engineering
by "Phil Marino" <[EMAIL PROTECTED]>
11) Re: Understanding my motor (ADC L91 & X91 6.7" motors revisited)
by Jeff Major <[EMAIL PROTECTED]>
12) Re: Controler
by "Bob Rice" <[EMAIL PROTECTED]>
13) Re: EVgrin - RAVolt takes first EV trip
by [EMAIL PROTECTED]
14) Re: Make it
by [EMAIL PROTECTED]
15) Re: regarding the Solectria Sunrise
by "Rush" <[EMAIL PROTECTED]>
16) Re: Make it
by Jim Husted <[EMAIL PROTECTED]>
17) Re: Electrical/Mechanical Engineering
by "TrotFox Greyfoot" <[EMAIL PROTECTED]>
18) Re: firefly batteries?
by "TrotFox Greyfoot" <[EMAIL PROTECTED]>
19) RE: Electrical/Mechanical Engineering
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
20) Re: how to control my separately excited DC motor....
by Jeff Major <[EMAIL PROTECTED]>
21) Re: Electrical/Mechanical Engineering
by "John A. Evans - N0HJ" <[EMAIL PROTECTED]>
22) Re: regarding the Solectria Sunrise
by Lee Hart <[EMAIL PROTECTED]>
23) Re: How low can you go?
by [EMAIL PROTECTED]
24) Re: vroombox and EV ?
by "Marty Hewes" <[EMAIL PROTECTED]>
25) Re: A123 and Shauns website
by keith vansickle <[EMAIL PROTECTED]>
--- Begin Message ---
On 6/27/07, Bill Dube <[EMAIL PROTECTED]> wrote:
Lots of questions that have been asked and answered before on this
list. Here are the answers again:
Cycle life = > 10,000 cycles to 90% DOD to 50% remaining capacity.
(1000 to 95% remaining capacity)
Larger cells are going to happen in a year or so. (Small cells
parallel excellently, so I don't get why folks care about this.)
Cycle life = > 10,000 cycles to 90% DOD to 50% remaining capacity.
(1000 to 95% remaining capacity)
Larger cells are going to happen in a year or so. (Small cells
parallel excellently, so I don't get why folks care about this.)
Hello Bill and other fellow EVers,
I've been a lurker of the EV list archives for a few years but it is
only now that I've decided to sign up and participate. The reason for
this is A123 batteries (and the discovery of Gmail!)
I'm very excited about the potential for A123 batteries to change the
automotive industry, particularly with PHEVs initially. They appear to
be a very "switched on" company, backed up by a superb product.
The RC guys (oh, for a "cheap" hobby!) seem to have done a lot of
excellent real-world testing of the M1 cells at the micro level and
are very pleased with the results, particularly when compared with
other's like Kokam etc. and that's good enough for me.
There are two hurdles that I see obstructing my investment in them however.
1. Upfront Cost.
2. BMS.
I've had a quote from A123 Systems for 1500 of the M1 cells and their
price was competitive with other Li when life-cycle is considered
(10,000 cycles to 50% is awesome), however I'd hope that a "group
purchase" might bring this price down closer to what I can
realistically afford upfront. I'm not asking for you to comment on
this because I know it's not your area.
So, on the BMS issue;
In rough dimensions I'd probably have approximately 40 groups in
series, with 30 paralleled cells in each group, to replace my current
12 X 12V 100Ah(C20) lead pack.
My first question is; Do the 30 individual cells in a parallel
grouping need individual attention or can I treat them as one because
they are in parallel with each other? In other words, when charging
"all" that I need to do is make sure each group of 30 cells reaches
3.6V but no more?
Sorry if you've answered this question before but I haven't managed to
stumble across it in the archives.
Thanks for your time and thank-you to all the other outstanding
participants in the wonderful EVlist community.
Shaun Williams.
www.electric-echo.com
--- End Message ---
--- Begin Message ---
Shaun Williams wrote:
>So, on the BMS issue;
>In rough dimensions I'd probably have approximately 40 groups in
>series, with 30 paralleled cells in each group, to replace my current
>12 X 12V 100Ah(C20) lead pack.
>My first question is; Do the 30 individual cells in a parallel
>grouping need individual attention or can I treat them as one because
>they are in parallel with each other? In other words, when charging
>"all" that I need to do is make sure each group of 30 cells reaches
>3.6V but no more?
yes, take care of each 3,2V cell group as a big cell.
You can go to 3,7V-3,8V for maximum capacity or 3,6V max for little more cyclic
life.
Philippe
the Froggy guy here ;^)
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--- End Message ---
--- Begin Message ---
Dan
You've asked this same question over and over again. Many knowledgeable and
experienced people have answered you - over, and over and over again.
They're probably getting tired of trying explaining this to someone who
refuses to believe them, and insults them at the same time.
You apparently just don't want to hear the answers - that it takes a lot of
experience, time, and money to build an EV controller
That's fine. Just go ahead and build one that works. Then let us know how
easy and cheap it was.
Please stop asking the same question.
Phil Marino
From: Dan Frederiksen <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: VOLTS vs AMPS & RE: Make It
Date: Tue, 26 Jun 2007 10:07:16 +0200
Lee, many keep saying that it's so impossible.
what is so time consuming about assembling it? where is the great
difficulty that ensures it will cost more?
please try to be specific, not just the 'try it, you will fail' mantra
why will it fail
Dan
Lee Hart wrote:
I'm a good engineer, and a pretty good technician. I *have* built products
of this sort. In my experience, it is impossible to build your own Curtis
controller for less money than Curtis charges, unless you place no value
on your time, your tools, and your training.
If you think you can do it, be my guest! Give it a try! Even if you fail,
you will have learned a lot. We'll talk more when you've finished.
_________________________________________________________________
PC Magazines 2007 editors choice for best Web mailaward-winning Windows
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--- End Message ---
--- Begin Message ---
There's a lot of mention about Firefly but I've never seen anything on this
company:
http://www.pwtcbattery.com/
Does anyone know anything about them?
____________________________________________________________________________________
Yahoo! oneSearch: Finally, mobile search
that gives answers, not web links.
http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC
--- End Message ---
--- Begin Message ---
The power level of a grid tie inverter is actually quiet low. The ones I
have seen are 10A at 240V. 1/2 the size of the smallest PFC charger
--- End Message ---
--- Begin Message ---
Thats because even 10A at 240v takes $13,000 of PV modules to
generate..... You can get them up to about 7kW if you want -- which
is more like $30,000 of PV modules.
Z
On 6/26/07, Jeff Shanab <[EMAIL PROTECTED]> wrote:
The power level of a grid tie inverter is actually quiet low. The ones I
have seen are 10A at 240V. 1/2 the size of the smallest PFC charger
--- End Message ---
--- Begin Message ---
Hey Danny,
I am pretty sure this was listed several weeks ago and
sold for $50,000, which looked like the reserve.
Looks like the same vehicle and seller, so I guess the
first deal fell through. See closed item no.
330123033575. Got deep pockets?
Jeff
--- Danny Miller <[EMAIL PROTECTED]> wrote:
> Oh yeah!
>
>
http://cgi.ebay.com/ebaymotors/Dodge-Caravan-NiMH-EV-Chrysler-EPIC-Electric-Vehicle-Rare-Collectors_W0QQcmdZViewItemQQcategoryZ6193QQihZ014QQitemZ330136589927QQrdZ1QQsspagenameZWDVW
>
> Wow I hadn't even heard of that one.
>
> 80 mile range. There are only 14 hrs left and it's
> only up to $15k!
>
> Danny
>
> Joseph T. wrote:
>
> > I can't read what you're saying (go to Gmail where
> you can choose to
> > have "plain" text)
> > but I'll comment about an Chrysler EPIC I saw on
> ebay with NiMH I
> > think. Super rare car!
> >
> > On 6/25/07, Tom Gocze <[EMAIL PROTECTED]> wrote:
> >
> >> * * * * * * * * * * * * * * * * * * * * * * * * *
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> >>
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>
____________________________________________________________________________________
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--- End Message ---
--- Begin Message ---
There were some problems in the past with trace inverters that supported
battery backup. Their gen-switch didn't and it backfed the lines during
an outage. This was discovered by the guy working on the lines that
assumed it was dead. This prompted a law in california that says you
can't have active autonomy. It has to be a manual switch.
So I have a sunnyboy inverter, very popular in CA. and it uses the line
cycles to create and time the AC it creates. It is damn frustrating
that when the power goes out on a sunny day that I have no power. I have
planned on remedying this.
But here is the rub.
We are use to infinite power at our fingertips, lets say I am useing
3Kw because the AC is on but the panels are only producing 2.5kw
When the power goes down, the panels can't supply the requested
load. Major brownout and damaged equipment may ensue.
This adds a new dimension to the project. To use the car as a whole
house backup it needs to supply more current than you think you need.
These are motor controller like power levels 200A at 240V, so that is
probably why AC propulsion uses the controller silicon to do the job.
I suppose xantrax sells "off-grid" units that will work without the grid
there, but i bet they are expensive for their power level.
Stationary generators often have backup, they must have some way of
inverting the output.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "GWMobile" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Cc: <[EMAIL PROTECTED]>
Sent: Monday, June 25, 2007 3:54 PM
Subject: Re: vroombox and EV ?
>I think noisemakers for evs are good for the transition period until the
> public gets used to them.
> Probably save yourself at least one collission lawsuit over a 20 yr
> period.
>
>
> On Mon, 25 Jun 2007 10:17 am, john fisher wrote:
>> this is not as silly a question as it sounds. Here in Santa Barbara we
>> have BEV rubber-tired trolleys that run up and down the main street. (
>> oh yeah they are very popular with the tourists- a great success) They
>> had to retrofit them with a noisemaker, precisely because people were
>> stepping off the curb right in front of them. I myself have been
>> startled to find one inches away, even with the sound device. They make
>> a low whine, I can find out more if anybody cares.
>>
>> JF
>>
>> Garret Maki wrote:
>>> I think it is a terrible idea. Attentive pedestrians are the answer,
>>> not noise pollution.
>>> -Garret
>> Hi EVerybody;
Garret's right, but we can't let Darwin's Law run it's course. Sigh!
This is why there arre so many stupid people out there!When yur driving your
EV you have to just be SUPER careful of the dummy pedestrians out there. At
least you CAN swerve, unlike a trolley or train.SO many times I have had to
STOP right behind careless and CLUEless people, just wandering right out in
the active part of the road WITHOUT even looking. Blabbing away on the cell
fone opr to their friends.It's illegal to use a hand held cell fone while
driving in CT. Good law, but it sure doesn't stop anybody!WALKING? Ha!
Another issue?They are SO shocked, oops, poor pun? At the EV right behind
them! "Sorry ,It's Electric" Ya say awhen they realize you are there. I
DIDN"T hear you!"
YMMV
Bob about to install OOGA horn
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Certainly basic math through calculus, linear algebra ( matrix and vector
math) and a course or two in differential equations would be a minimum for
any engineer.
Some statistics would help ( for anyone, not just engineers) and for EE's
( I'm an ME, so I'm kind of guessing here) I would think Fourier analysis
and maybe some discrete math would be needed.
Phil Marino
From: "Joseph T. " <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Electrical/Mechanical Engineering
Date: Tue, 26 Jun 2007 02:06:38 -0400
What kind of math is required and, or recommended to become an
electrical or mechanical engineer?
I hear alot people saying that they're engineers here, so this will
determine if it's a bluffing!
_________________________________________________________________
Get a preview of Live Earth, the hottest event this summer - only on MSN
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--- End Message ---
--- Begin Message ---
Thanks Jim,
Hope you didn't have to saw one in half.
Jeff
--- Jim Husted <[EMAIL PROTECTED]> wrote:
> Hey Lee, Jeff
>
> The L91 has just one wire per slot, although there
> is
> a bottom and a top winding, so depending on how you
> count it, lol. I've not seen the X91.
> Hope this helps 8^)
> Jim
>
>
>
>
>
____________________________________________________________________________________
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--- Begin Message ---
----- Original Message -----
From: "Phelps" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, June 25, 2007 6:29 PM
Subject: Re: Controler
>
>
>
> -------Original Message-------
>
> From: Phelps
> Date: 6/25/2007 5:40:49 PM
> To: ev@listproc.sjsu.edu
> Subject: Controler
>
>
> Just to keep it all straight.. When I wrote the short message about
(making
> It.).I lost most everybody here you assumed that I was thinking about
making
> a
> Electronic controlled controller....
>
> Nope never said that and never wanted to do that..
>
> I was just thinking about a mechanically driven switch.. Not as nice as
> What you are all use to.. Probably noisyer if it could be done ..
> But if it could be done.. It would be cheaper..
>
> Building a fancy mechanically switch .. Is that so hard .. Maybe ..
Maybe
> Not.
>
> I don't know but I sure do Have the thought.
>
>
> Mitchell
>
> Hi Mitchell an' All;
Been there , done that. About 40 years ago, in my EV deformative years!
Forgetabout it! Noisy, I'm sure relatively inificient? It was suggested I
call my EV chassis "The Comet"!With all the blue flames, etc. And I was only
using two golf cart motors on that one, one for each rear wheel. Maybe with
precision maching of the mechanical parts and better arc supression? Solid
state stuff is more elegent, or EVen a basic series series Parallel
contacter setup, if you MUST?
Seeya
Bob
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Joseph,
Tell us later about the performance!
I'll post this after I get my DC-DC converted online.
And a little question for you...In order to go in reverse do you
need a forward/reverse contactor? You can just shift in to reverse
instead, right?
I use the transmission for reverse - the motor always runs the same
direction. Clutchless shifting has been a breeze so far: it drops
right into gear without any grinding.
Rob
RAVolt.com
--- End Message ---
--- Begin Message ---
-----Original Message-----
From: Dan Frederiksen <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Mon, 25 Jun 2007 7:12 pm
Subject: Re: Make it
A smart man could easily convey the needed knowledge to someone like
me. Genius makes the complex simple.
Perhaps that is the problem. Perhaps those on this list that you have
been insulting is not as smart as you. That is not their fault. That is
just the way it is. Everyone has been trying to explain, at scream
level, that their accomplishments are the result of years of grueling
hard work - not geniusness. I certainly can not imagine how years of
work can be explained in just a few sentences sufficiently that someone
could duplicate those years of progress. If that were possible, I don't
think universities would exist. But then I am certainly no genius.
From my personal design experience, a major element of the design is
always to keep it simple. With that effort, a current project requires
a 10" X 12" 90 mil PCB with 3 oz copper and 10 mil traces. Low bidder
for that cost $450.00 for three proto boards. The capacitors, including
low ESR high ripple current Illinois Capacitors are $272.87. The
resistors, SMT capacitors etc. come to $112.18. The controller chips,
transistors and power MOSFETS come to $208.48. The inductors came from
low bidder which was $400.00. The inductors had to be custom built
because I could not find any off the shelf units that even come close
to fitting the use. I have yet to get quotes from a machine shop to
fabricate the heatsinks. So that comes to $1443.53, not including the
heatsink, enclosure, hardware, or labor. This is all for a 140 Amp
DC-DC converter. I have spent almost a year trying to simplify the
design to get the price down and that is the best I have managed so
far. My point is I simply do not know how to describe in a few
sentences how to do what you are asking, or get the cost in line with
your beliefs.
You can call me stupid as I don't claim to be smart. But, just like
everyone else on this list that you are attacking, I am WORKING on it.
Ken
________________________________________________________________________
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--- End Message ---
--- Begin Message ---
Lee wrote -
> Batteries
> central battery tunnel slides out the front for easy servicing
> size 120"L x 12"H x 15"W, 1500 lbs, holds up to 24 T-145 6v 240ah
> (24 GM/Ovonic nimh, 12v 90ah)
Balancers with the batteries?
Rush
Tucson AZ
www.ironandwood.org
www.TEVA2.com
www.Airphibian.com
--- End Message ---
--- Begin Message ---
Hey Dan
You know, you really are a cowboy! Come in to town,
guns blazing, calling all the good town folk names
like "otmeal" or "your heiness" and then you wonder
"why" no one wants to talk to you!
Furthermore, there are two kinds of "smart", book
smart, and good old fashion common sense, of which IMO
you possess none!
The funniest thing to me (the thing that started your
whole rant) is your fear Otmar is getting filthy rich
off his controllers. One day a big corp will produce
your cheap controller, create lots of crappy factory
jobs with "don't meet ends wages" while the CEO's
enjoy huge profits and bonuses. God what a perfect
world you invision! At least at that point you will
have something to bitch about! But hey you'll have
that super "cheap" controller you wanted.
FWIW take the silver spoon out of your mouth, take the
I'm the worlds greatest man sign off your back, learn
some basic "people" skills, and maybe, just maybe,
you'll find less friction towards your posts.
Well that, and maybe try to actually become a doer!
EVery one of the people you are soooooo eager to slam
has become respected through their works not idle
words.
Just something to chew on, if you decide to remove the
silver spoon first 8^)
Jim Husted
Hi-Torque Electric
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--- Begin Message ---
I signed up for an engineering degree at The University of North Texas
with a mechanical focus. I had to get through pre-calculus before I
could even start the degree's math courses. My schedule had me taking
a math course Every semester through the end of the course.
Whoever goes for an engineering course better at least have a passing
fancy for math.
I don't. { : (
Trot, the merely-technical, fox...
On 6/26/07, Phil Marino <[EMAIL PROTECTED]> wrote:
Certainly basic math through calculus, linear algebra ( matrix and vector
math) and a course or two in differential equations would be a minimum for
any engineer.
Some statistics would help ( for anyone, not just engineers) and for EE's
( I'm an ME, so I'm kind of guessing here) I would think Fourier analysis
and maybe some discrete math would be needed.
Phil Marino
--
| /\_/\ TrotFox \ Always remember,
| ( o o ) AKA Landon Solomon \ "There is a
| >\_/< [EMAIL PROTECTED] \ third alternative."
--- End Message ---
--- Begin Message ---
Actually, as a minor nitpick, they're using lead impregnated graphite
foam for their plates. It's really nifty stuff and looks more like a
silvery pillow than a block of carbon. It is very lightweight though.
Trot, the researchin', fox...
On 6/25/07, Bruce Weisenberger <[EMAIL PROTECTED]> wrote:
They are designers. From 3 to 30 people in 3 years per
a Peoria Newspaper article linked to their website.
The are designing the batteries for Husqvarna
gardening equipment such as weed eaters, lawnmowers.
They are not building product. They are R & D and then
selling the design to the individual manufactures to
build their own batteries. In May 2007 they signed a
manufacturing agreement with Crown Battery In April
thay signed an agreement with North Star Battery.
Read the press releases and news articles.
www.fireflyenergy.com
With the release to Crown there maybe hope for use
EV'er to see these batteries in the next year or 2.
The Weight savings is in the lack of main plates.
Instead of plates with lead paste spread across them
they use a Carbon Fiber screen. So image a Trojan 125
weighing only 16.5 lbs instead of 66 lbs. On a 72 Volt
pack we are talking 200 lbs verse 800 lbs. Or imagine
Johns White Zombie from his roughly 500 lbs reduced
to 125 lbs. John that is only a guest on weight of
your present pack weight no insult intended. But
essentially if batteries where a 1/4 of the weight
where will EV be tomorrow. This is what makes Lithium
batteries so attractive. IF Carbon Fiber plates can do
the same for Lead then So be it. And hopefully at a
similar price to lead batteries now. I know I'm
dreaming here.
--
| /\_/\ TrotFox \ Always remember,
| ( o o ) AKA Landon Solomon \ "There is a
| >\_/< [EMAIL PROTECTED] \ third alternative."
--- End Message ---
--- Begin Message ---
For electrical Engineering my class track at Old Dominion University
has:
Intro to math
College Algebra
Pre calculus
Calculus 1
Calculus 2
Differential Equations
Statistics
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of TrotFox Greyfoot
Sent: Tuesday, June 26, 2007 10:52
To: ev@listproc.sjsu.edu
Subject: Re: Electrical/Mechanical Engineering
I signed up for an engineering degree at The University of North Texas
with a mechanical focus. I had to get through pre-calculus before I
could even start the degree's math courses. My schedule had me taking a
math course Every semester through the end of the course.
Whoever goes for an engineering course better at least have a passing
fancy for math.
I don't. { : (
Trot, the merely-technical, fox...
On 6/26/07, Phil Marino <[EMAIL PROTECTED]> wrote:
> Certainly basic math through calculus, linear algebra ( matrix and
> vector
> math) and a course or two in differential equations would be a minimum
> for any engineer.
>
> Some statistics would help ( for anyone, not just engineers) and for
> EE's ( I'm an ME, so I'm kind of guessing here) I would think Fourier
> analysis and maybe some discrete math would be needed.
>
> Phil Marino
>
--
| /\_/\ TrotFox \ Always remember,
| ( o o ) AKA Landon Solomon \ "There is a
| >\_/< [EMAIL PROTECTED] \ third alternative."
--- End Message ---
--- Begin Message ---
Hi Zeke,
I'll put a few comments in.......
--- Zeke Yewdall <[EMAIL PROTECTED]> wrote:
> So..... I got my motor today -- haven't picked it up
> from the
> warehouse yet, but I'm going to stop by tonight and
> get it. It's a
> 13" GE separately excited motor -- 1000rpm base
> speed at 96 volts.
> Supposedly about 21HP continuous rating at 96 volts.
> Been used on a
> couple of EV's before, since 1979, but supposedly
> only has 5,000 total
> miles on it.
>
> Now... I've looked for a suitable controller for it,
> and the largest
> ones for separately excited motors seem to be around
> 48 volts and
> 600amps, or about 96 volts and 400 amps. I was
> thinking of running it
> more like 120 or 144 volts (which the previous owner
> did run in an
> EV), and more like 500 A or so (that depends alot on
> how much the
> batteries will handle, I guess). He said that it
> would pull 600A at
> 144 volts if the batteries could handle it.
>
> The previous owner just used field control I believe
> -- turn main
> contactor on and the motor starts turning. Then you
> use the clutch,
> just like in a regular ICE car, and the accelerator
> decreases the
> field current to increase the speed. So, it occurs
> to me that I could
> do the same (I'm keeping the clutch).
Two things here. You get clutch wear. And no current
limiting except maybe a fuse.
> But, I
> understand that you can
> get a bit better performance if you also do armature
> control... Could
> I use a controller such as for a series DC motor for
> the armature,
Maybe. You will not have a series field in the
armature circuit, so the controller might not behave
as intended. It is possible the big motor has enough
inductance in the armature, could possibly have
interpoles and comm coils which could help. I'd give
it a try.
> then a smaller controller for the field, with
> reverse control (so it
> first increases the armature voltage and then
> decreases the field
> voltage as the accelerator is pressed further down)
You will benefit from a control strategy that also
increases field current as the armature current
increases. This will slow down rotation, but give you
more torque per amp. You'll slow down anyway if the
load goes high enough to put it into current limit, so
increase the field first and keep it out of current
limit as long as you can. This current strategy
should take priority over the accel pedal position, in
my opinion.
> And, how would
> this react with regards to regen? (the whole reason
> I got this motor
> instead of a 9" ADC) My understanding with regards
> to regen (driving
> an Electrek which has a very similar motor with
> field control), is
> that if you adjust the field currrent to the point
> where the base rpm
> of the motor would be lower than the actual rpm, it
> will drive current
> backwards into the battery to try to slow down. If
> the base rpm of
> the motor is higher than the actual rpm, it will
> pull current from the
> battery to try to speed up.
Yeah.
> But how would this work
> if I've got a
> conventional chopper controller controlling the
> armature? Big bypass
> diodes?
I think that diode is already in there, for free.
Maybe others can comment if it would be up to the
task.
Good luck,
Jeff
>
> Initially, I might just set it up with field control
> only, but just
> wondering what the options are for a more advanced
> system --
> preferrably one that I can buy and not build myself
> (I have built
> power control circuits before -- and blown up a bit
> of silicon -- I'd
> rather just have a controller that works, than one
> that I have to
> fiddle around with it)
>
> Z
>
>
____________________________________________________________________________________
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--- Begin Message ---
Before I actually started my degree program I took
Algebra
Trig
Calculus I
Then, when I began my BSEE program at Arizona State, 1981-1984
Calculus II
Elementary Differential Equations
Elementary Linear Algebra
Advanced Math for Engineers and Scientists
Probability/Statistics for Engineers (elective)
I don't remember a lot of it since I don't use it regularly in my
career, but I kept my notes and could get back into it with a little
work. It "has" helped when my daughter needs help with her schoolwork :)
One thing I do know is that having a handle on math and how it applies
to life/work/design/technical stuff/etc. will truly help one understand
what may be going on in whatever field you apply it to. Plus, if you
can do the math, you can do everything else that goes along with other
college courses. We used the math we learned in every single
engineering and science course with the exception of most computer courses.
john
--- End Message ---
--- Begin Message ---
Lee wrote:
>> Batteries
>> central battery tunnel slides out the front for easy servicing
>> size 120"L x 12"H x 15"W, 1500 lbs, holds up to 24 T-145 6v 240ah
>> (24 GM/Ovonic nimh, 12v 90ah)
Rush asked:
> Balancers with the batteries?
The whole point of the Sunrise kit is to provide a "glider" for builders to
attach their own parts as desired. The Solectria Sunrise took the "high tech"
approach; AC motor, carbon fiber composites, expensive batteries, etc. That
provided one price/performance data point.
So, we are building one that goes in the opposite direction, to provide a data
point at the other end of the curve. DC motor, cheap batteries, ordinary
fiberglass, etc. We're using flooded golf cart batteries, because they are the
*cheapest* you can get. I'll probably put one of my Battery Balancers in it
just for instrumentation and data logging; but not balancing.
--
I would not waste my life in friction when it could be turned into momentum. --
Frances Willard
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
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--- Begin Message ---
Thanks, Chris and Lee for the confirmation.
My Zilla was set to 110 Volts for the low battery volts (LBV). That
would allow 8.46 volts per battery if pushed with a low SOC. So, I
reset it to 137 volts. Makes me more comfortable knowing I can't pull
the pack below that level.
Ken
As I understand it, 1.75 volts per cell (10.5 volts for a 12V battery)
is the lowest you should ever take any lead-acid battery under any
circumstances. So, if you were to continue drawing 100A, soon the
battery voltage would dip under 10.5 volts, and you'd know that you're
then decreasing the life expectancy of the battery. I believe this
applies regardless of discharge current, even letting them sit
(self-discharge).
--
Christopher Robison
-----Original Message-----
From: Lee Hart <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Mon, 25 Jun 2007 10:44 am
Subject: Re: How low can you go?
[EMAIL PROTECTED] wrote:
The Optima data sheet indicates that 10.5 volts is the cut off low >
voltage for the reserve capacity.
> Should that voltage also be considered the maximum “sag” voltage
during > a high current draw regardless of the state of charge or sag
time?
Yes; 10.5v is a good safe cutoff voltage regardless of current. You are
very unlikely to reverse a cell if you don't go below this.
If you *know* all cells are matched, and are trying to produce big
numbers for a data sheet, you can discharge below this point. Battery
manufacturers do this on their data sheets to inflate the amphour
ratings.
The real danger is that when a cell goes completely dead, it develops
high resistance. The other cells in series with it, that still have
charge, will force current to keep flowing through the dead cell. This
high current and high resistance cause severe heating in the dead cell.
The plates will warp, it will boil its electrolyte, and things will get
very bad very fast!
So, the 10.5v limit comes from the assumption that 1 cell out of the 6
in a 12v battery has gone dead. The 5 good ones are still delivering 2v
each (2 x 5 = 10v) and there is just 0.5v left across the dead one (1 x
0.5v = 0.5v), so there is 10.5v across the battery as a whole.
-- Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
________________________________________________________________________
AOL now offers free email to everyone. Find out more about what's free
from AOL at AOL.com.
=0
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--- Begin Message ---
Maybe I'll attach bear bells to the wheels :).
Marty
----- Original Message -----
From: "Bob Rice" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, June 26, 2007 8:09 AM
Subject: Re: vroombox and EV ?
----- Original Message -----
From: "GWMobile" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Cc: <[EMAIL PROTECTED]>
Sent: Monday, June 25, 2007 3:54 PM
Subject: Re: vroombox and EV ?
>I think noisemakers for evs are good for the transition period until the
> public gets used to them.
> Probably save yourself at least one collission lawsuit over a 20 yr
> period.
>
>
> On Mon, 25 Jun 2007 10:17 am, john fisher wrote:
>> this is not as silly a question as it sounds. Here in Santa Barbara we
>> have BEV rubber-tired trolleys that run up and down the main street. (
>> oh yeah they are very popular with the tourists- a great success) They
>> had to retrofit them with a noisemaker, precisely because people were
>> stepping off the curb right in front of them. I myself have been
>> startled to find one inches away, even with the sound device. They
make
>> a low whine, I can find out more if anybody cares.
>>
>> JF
>>
>> Garret Maki wrote:
>>> I think it is a terrible idea. Attentive pedestrians are the answer,
>>> not noise pollution.
>>> -Garret
>> Hi EVerybody;
Garret's right, but we can't let Darwin's Law run it's course. Sigh!
This is why there arre so many stupid people out there!When yur driving
your
EV you have to just be SUPER careful of the dummy pedestrians out there.
At
least you CAN swerve, unlike a trolley or train.SO many times I have had
to
STOP right behind careless and CLUEless people, just wandering right out
in
the active part of the road WITHOUT even looking. Blabbing away on the
cell
fone opr to their friends.It's illegal to use a hand held cell fone while
driving in CT. Good law, but it sure doesn't stop anybody!WALKING? Ha!
Another issue?They are SO shocked, oops, poor pun? At the EV right behind
them! "Sorry ,It's Electric" Ya say awhen they realize you are there. I
DIDN"T hear you!"
YMMV
Bob about to install OOGA horn
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--- Begin Message ---
Shaun
sure glad you became active on the list as I would not
have found your web site otherwise. It is a well done
website and looks like a good little ECHO EV
thanks for sharing
kEVs
--- Shaun Williams <[EMAIL PROTECTED]>
wrote:
> On 6/27/07, Bill Dube <[EMAIL PROTECTED]>
> wrote:
> > Lots of questions that have been asked and
> answered before on this
> > list. Here are the answers again:
> >
> > Cycle life = > 10,000 cycles to 90% DOD to 50%
> remaining capacity.
> > (1000 to 95% remaining capacity)
> >
> > Larger cells are going to happen in a year or so.
> (Small cells
> > parallel excellently, so I don't get why folks
> care about this.)
>
> >
> > Cycle life = > 10,000 cycles to 90% DOD to 50%
> remaining capacity.
> > (1000 to 95% remaining capacity)
> >
> > Larger cells are going to happen in a year or so.
> (Small cells
> > parallel excellently, so I don't get why folks
> care about this.)
>
> Hello Bill and other fellow EVers,
>
> I've been a lurker of the EV list archives for a few
> years but it is
> only now that I've decided to sign up and
> participate. The reason for
> this is A123 batteries (and the discovery of Gmail!)
>
> I'm very excited about the potential for A123
> batteries to change the
> automotive industry, particularly with PHEVs
> initially. They appear to
> be a very "switched on" company, backed up by a
> superb product.
>
> The RC guys (oh, for a "cheap" hobby!) seem to have
> done a lot of
> excellent real-world testing of the M1 cells at the
> micro level and
> are very pleased with the results, particularly when
> compared with
> other's like Kokam etc. and that's good enough for
> me.
>
> There are two hurdles that I see obstructing my
> investment in them however.
> 1. Upfront Cost.
> 2. BMS.
>
> I've had a quote from A123 Systems for 1500 of the
> M1 cells and their
> price was competitive with other Li when life-cycle
> is considered
> (10,000 cycles to 50% is awesome), however I'd hope
> that a "group
> purchase" might bring this price down closer to what
> I can
> realistically afford upfront. I'm not asking for you
> to comment on
> this because I know it's not your area.
>
> So, on the BMS issue;
> In rough dimensions I'd probably have approximately
> 40 groups in
> series, with 30 paralleled cells in each group, to
> replace my current
> 12 X 12V 100Ah(C20) lead pack.
>
> My first question is; Do the 30 individual cells in
> a parallel
> grouping need individual attention or can I treat
> them as one because
> they are in parallel with each other? In other
> words, when charging
> "all" that I need to do is make sure each group of
> 30 cells reaches
> 3.6V but no more?
>
> Sorry if you've answered this question before but I
> haven't managed to
> stumble across it in the archives.
>
> Thanks for your time and thank-you to all the other
> outstanding
> participants in the wonderful EVlist community.
>
> Shaun Williams.
>
> www.electric-echo.com
>
>
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