EV Digest 5996
Topics covered in this issue include:
1) Re: What is the future of Li BMS?
by Jack Murray <[EMAIL PROTECTED]>
2) RE: EV2 GM TV spot.
by Cor van de Water <[EMAIL PROTECTED]>
3) Re: Lighter Porsche 914
by "Roland Wiench" <[EMAIL PROTECTED]>
4) Re: $25,000 Performance Car
by "Mike Ellis" <[EMAIL PROTECTED]>
5) Re: Lithium-ion batteries & Valence Group buy ( Michaela EV Disappointment)
by "Death to All Spammers" <[EMAIL PROTECTED]>
6) Re: Today Show - Hit the Road with this Electric Car
by "Mike Ellis" <[EMAIL PROTECTED]>
7) RE: Citicar on Hummer commercial
by Cor van de Water <[EMAIL PROTECTED]>
8) Fleet Mgr creating a list of Ford Ranger EV interested names
by bruce parmenter <[EMAIL PROTECTED]>
9) Re: lee's emeter companion?- DC-DC isoloation?
by "Phil Marino" <[EMAIL PROTECTED]>
10) Wayland and WZ on Dutch TV
by Victor Tikhonov <[EMAIL PROTECTED]>
11) Re: lee's emeter companion?
by Victor Tikhonov <[EMAIL PROTECTED]>
12) Re: Bad aux battery affects Voltage Sag?
by Patrick Clarke <[EMAIL PROTECTED]>
13) Re: lee's emeter companion?
by Lee Hart <[EMAIL PROTECTED]>
14) Re: Lighter Porsche 914
by Lee Hart <[EMAIL PROTECTED]>
15) Re: What is the future of Li BMS?
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Citicar on Hummer commercial
by "Mike Ellis" <[EMAIL PROTECTED]>
17) (no subject)
by Reverend Gadget <[EMAIL PROTECTED]>
18) RE: Lithium-ion batteries & Valence Group buy ( Michaela EV Disappointment)
by "Don Cameron" <[EMAIL PROTECTED]>
19) Re: Wayland and WZ on Dutch TV
by Bill Dube <[EMAIL PROTECTED]>
20) Re: lee's emeter companion?- DC-DC isoloation?
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: Golf Carts, What Can They Teach?
by "Tom Shay" <[EMAIL PROTECTED]>
22) RE: Bad aux battery affects Voltage Sag?
by Cor van de Water <[EMAIL PROTECTED]>
--- Begin Message ---
Jukka, interesting comments. But why not just let the bad cell fail,
and then replace it? It does need to be identified, that is critical,
but might be a lot more effective to do that than go to a lot of trouble
and expense to keep all the batteries equal. just a thought.
Jack
Jukka Järvinen wrote:
The most wrong way to manage Lion cells is to cure symptoms. The cells
behaviour can be predicted easily as long you know the surroindings and
enviromental conditions.
Rarely cells fail just by using them. You can easliy see the potentially
failing cell by measuring it before putting it evne in the pack. I could
say that 98% of all failed cells I have had have resigned from their
post due misuse. At the moment my experience is limited to a bit over 1
000 000 Ahs in total of used and tested lithium cells. (Co,Mn,Fe)
Most wrong way is to find the balance with voltage only. At least with
the cells I have used. Pack is badly out of balance if you charge all
cells to 100% SOC and start using them from there. Weakest link will
fail first and much sooner thant you expect. If you start bypassing the
current over the cells you will need heavy and perhaps even expencive
way to do it.
Voltage is a good reference but not only source of SOH information.
Track current, temperature and history data and it will work.
And now someone thinks it will be expencive. It can if not done correctly.
Lets say you get the double mileage with same pack of cells with BMS.
Why ?
Without it the weakest link will use most highest individual DOD in the
pack. So it has lowest cycllic life too. Best cells have less and less
DOD in every cycle since their rate of death is much lower. There will
be 200 to 300 % difference in the lifetimes. With certain conditions
even more.
By adjusting the operational capacity window parameters you can choose
the rate of death. Higher cell voltages in end of charge fastens the
electrolyte dissolving. Also using heat to lower the impedance during
charging you can adjust the lifetime of the cells.
This is where I have the border between "BMS" (voltage limitations with
tempsensors) and BMS (historical database to define lifetime trends and
capacity based balancing to match the cyclic and electrolyte lifetime)
Now the 10-20% added price on the plain Lithium cells has nicely been
justified by the doubled lifetime. That's the cost of BMS today.
If we would live in perfect world and all cells would be identical and
electrolyte would not be damaged by overcharging, all extra energy put
to cell would just transform to cold air or light or cosmic radiation..
We would be able to make briefcases with 300 kWh energy...
There are pending patents on the issues mentioned up here earlier and
when they are all public anyone with non-commercial activities can find
their ways to implement it.
I can see 30 kWh Lion packs with all necesary auxiliary devices (3200W
Chargers, computers, touch screens, controller boards for pedals and
contactors, cell electronics) with less than 15000 USD in near future.
VERY doable. When all gets to it's place you can even half that price.
So what I do think about BMS over all (OEM world)... In future there
will not be a BMS sold separately.
It integrates to cell structures. OEM type manufacturing of the
technology is already existing. The "BMS" makers will still be there and
doing their thing. From there they do the very important work to test
the theories and existing technology. They do not eat anything without
chewing it throughly.
There are still at least 500 Lithium battery manufacturers world wide.
They sell to anyone they can. Small players will vanish or stay in small
markets. Big players buy all potential technology they see and it
evolves from there as any other industry.
Just my personal opinion...
-Jukka
Mark Fowler kirjoitti:
Hi all,
John's and Victor's Li-BMS systems monitor the voltage and bleed off
excess charge current.
They attach (in parallel) to an already connected battery string.
The circuit boards in these links actually connect the batteries into a
series string.
All current runs through the circuit itself, allowing the circuit to
monitor the current as well as voltage, and to disconnect the batteries
in fault situations.
This is fine for relatively low currents (like in R/C models or bikes or
scooters) but doesn't scale up too easily without redesigning how the
whole thing works (i.e. where the current flows).
These systems are cheap because of mass production.
(I wonder how big the R/C market is in terms of total KWh of batteries
compared to the EV market...)
There are chips like http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2931
that do the bulk of the work for you - just wrap a circuit around them
to plug everything in to.
Once again - the problem is that these chips expect the current to be
flowing through them to do their job, so they only handle low currents.
I'm sure there's a way of building a circuit based on such a chip that
used a current divider so that the chip only saw a tiny fraction of the
real current, enabling it to handle EV currents and still give useful
voltage info and some overcharge regulation (through another heat-sunk
part of the circuit).
(I'm an electronics noob, so don't ask me how to do it :-)
Mark
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Don Cameron
Sent: Tuesday, 10 October 2006 1:43 PM
To: [email protected]
Subject: RE: What is the future of Li BMS?
We already have people on this list developing lithium BMS for higher
amperage EV needs today. Victor should have something out soon.
Also, I
think John L has or is developing something.
I sure like these little modules, at $45 for the 10 cell unit,
needing 9
units for 312V, approx $500 for BMS is pretty good. Too bad the max
current
draw is only 27A.
I wonder, it the circuit can be modified easily to handle 300A or even
1000A max draw?
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Ryan Stotts
Sent: October 9, 2006 7:49 PM
To: EVDL
Subject: What is the future of Li BMS?
Look at these products and based on what you see, what do you foresee
on the
future price for items such as this and also, the reality and
likelihood of
us owning products like this?
Is THIS the beginnings of an off the shelf universal BMS system?
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=911
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=908
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=912
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=910
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=909
Where do we go from here? What is to be done next? Do items like
this do
anything for us; or are we no further along now then we were?
If this item is nothing; then what will be something and when will
that be
and what will it be?
I see a little PCB and silicon in those pics. How is the imagined
BMS in
your head different then these? How is it better? What does it do
different? How much does it cost and is it cheaper? How will a BMS
ever be
cheaper? What components are currently not available now that need
to be?
How will any prices go down? You know what component prices are. Have
prices for any components ever gone down? When and how much?
Is BMS a reality or a farce? Will or will not happen in our lifetimes?
--- End Message ---
--- Begin Message ---
The movie comes up fine, but all you see is a
nondescript car with "crash test" style markings on
its exterior and it looks as if it is running on
a test track with a 3rd rail.
It certainly is an ad made for GM and apparently
for a production EV, but before you get riled up
please check the BMW ad: it is for the
"New 2001 BMW" sooooo - this is work from before
the big crushing. Too bad.
BTW, this artist has made soundtracks for movies
and ads, that's why they are on his site.
See his bio.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Mike Phillips
Sent: Tuesday, October 10, 2006 7:49 AM
To: Lawrence Rhodes
Subject: Re: EV2 GM TV spot.
I use Quicktime alot but all I got was the sound track.
Mike
--- In [EMAIL PROTECTED], "Lawrence Rhodes" <[EMAIL PROTECTED]> wrote:
>
> http://homepage.mac.com/ptiano/iMovieTheater20.html Is this old
news? I
> never saw this before. Click on GM TV Spot. Lawrence Rhodes.....
>
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, October 10, 2006 9:21 AM
Subject: RE: Lighter Porsche 914
> It's been my experience that when you make iberglass thick enough, and
> strong enough, to stand up to daily use it ends up being /heavier/ than
> steel.
>
> Take for example modern Corvette's, all that fiberglass and the vehicle
> weighs over 3,000 lbs.
That's true, fiberglass panels for race cars are very thin, sometimes they
are only chop glass in resin spray on to a mold. We call these a 60 minute
life, as where they will start to crack up in that amount of time.
In racing panels, there are no inner panels as they are in street sheet
metal panels.
Some panels and bodies are replaced after every race. If you live in a area,
where there is a great temperature change in one day like 80 degrees, this
has crack up the panels and cause seperation of the joints.
Street type fiberglass panels are lay up cloth that may be as thick as 1/4
inch in some places. In very large panels, they may be reinforce with lay
in tubing with mounting attachments.
The advantage of fiberglass panels for racing is that only a thin outside
shell is use, and if gets damage, it can be replace easily and glue in a new
section in with seconds.
Roland
>
> > This was just discussed in the 914 google group.
> >
> > http://groups-beta.google.com/group/914ev
> >
> >
> >
> > Here's Some links to fiberglass replacement parts (mostly for racing).
> >
> > http://www.ultimate914.com/MOTORSPORTS_WE/Price_Listx.html
> >
> > http://www.gt-racing.com/GTR914.pdf?PHPSESSID=6fb71ba88dd0cba848667eb47a64b6
> > d0 (fiber or carbon!)
> >
> > They are a little on the pricey side, but you can get replacement hoods,
> > trunk lids, rear quarter panels, door skins.
> >
> > Remember that in addition to the cost of the parts, you'll have to add
> > installation, finishing and painting (unless you do it all yourself).
> >
> > I'm not sure what the steel parts weigh, but a 12 lb hood, 11 lb trunk
> > lid
> > is sure to cut off some weight. I'm just not sure how much.
> >
> > Mike
> >
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> > Behalf Of Mark E. Hanson
> > Sent: Tuesday, October 10, 2006 8:29 AM
> > To: [email protected]
> > Subject: Lighter Porsche 914
> >
> > Hi,
> >
> > I was curious from the Porsche conversion guru's how to lighten up a
> > Porsche 914. I'm looking at buying one and it has the usual belly pan
> > rust
> > so I'll need to replace that probably from auto atlanitc.com. Does
> > anyone
> > have recommendations on fiberglas etc body parts replacements that would
> > make it lighter. It weighs 2100lbs start weight and the Ghia is 1900
> > lbs
> > but the Porsche looks like a more fun car with the removeable roof so
> > I'll
> > probably buy that tomorrow.
> >
> > Thanks,
> > Mark
> >
> >
> > ---------------------------------
> > How low will we go? Check out Yahoo! Messenger's low PC-to-Phone call
> > rates.
> >
> >
>
>
> --
> If you send email to me, or the EVDL, that has > 4 lines of legalistic
> junk at the end; then you are specifically authorizing me to do whatever I
> wish with the message. By posting the message you agree that your long
> legalistic signature is void.
>
>
--- End Message ---
--- Begin Message ---
Why a Corvette? There are lighter, better handling, and more
comfortable doner sports cars to use.
-Mike
On 10/8/06, Jack Murray <[EMAIL PROTECTED]> wrote:
So we now have $9,600 in batteries, $6,500 for motor and controller =
$16,100. We put it into a $4,000 1984-91 Corvette.
--- End Message ---
--- Begin Message ---
> That is a total peanut gallery cop out. If you are going to cite
something
> - come on, dig it up! What study do you have that says 50%?
>
>
> Try here: http://www.evadc.org/pwrplnt.pdf
>
Sorry, just too lazy and it's been discussed too much in the past for
someone to state coal-fired electricity only makes 5% of an ICE's
emissions.
--- End Message ---
--- Begin Message ---
It was a Telsa Roadster.
D'Oh! Too bad the transmission broke (from giving it a beating the day
before, they say)
I sooooo want this car. How much money can one raise selling
sponsorships? I'm wondering if my power company would give me some
dough to put their brand on it.
I think I have to resign myself to not having one. :(
-Mike
On 10/9/06, ROBERT GOUDREAU <[EMAIL PROTECTED]> wrote:
http://video.msn.com/v/us/v.htm?g=98835414-1D35-4DE6-9A2F-BF846BCCA9C7&f=&fg=copy
--- End Message ---
--- Begin Message ---
Good Idea!
I just sent an email to Hummer to ask
where I could get that little car,
because I heard it needs no gas ;-}
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of David Roden
Sent: Tuesday, October 10, 2006 6:16 AM
To: [email protected]
Subject: Re: Citicar on Hummer commercial
> Reaches brilliant conclusion, runs from building, hops into his EV
(complete
> with electric whine) and goes out to buy a GM Hummer.
I wonder how many calls GM have gotten asking where to buy one of those
little electric cars.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- End Message ---
--- Begin Message ---
[Note: Someone else may also have already POSTed about this same
topic]
Steve Miller, City of Mountain View Fleet manager has 6 Production
Ford Ranger Electric Trucks. All run OK but one has a charging
issue so its pack is discharged. Steve is seeking service for his
Production Ford Ranger EV fleet. I have already advised him of how
to contact Blue Sky Motors to have Kitty Rodden advise him of what
services she offers.
All of his fleets Ford Ranger EVs are white in color and will look
similar to
http://www.buysell.com/webphoto/1954/1954960240.jpg
All have an aluminum truck bed tool box mounted behind the cab. The
tool box is about 1.5 ft deep, fits across the bed, and sits up
about 3 inches above the top of the bed. The tool box most likely
looks similar to:
http://www.tool-box-store.com/images/uws_single_lid_big_371_176.jpg
and can be removed if unwanted.
Steve is interested in building a list of names of people who would
be interested in purchasing: one, some, or all of his EVs at a at
future date in a sealed bidding auction. The Ranger EV with the
charging issue may be sold sooner in an 'as is' condition.
If you are interested in being put on his list, send an email to
[EMAIL PROTECTED] (DO NOT send an email to me)
Because this POST will likely be reprinted, please note: Steve will
not have bandwidth to act as a Ford Ranger Electric truck FAQ (how
fast, how far, etc.). There are other resources for that
information. Steve is only interested in building a list of
knowledgeable interested people for his future-date sealed bidding
auction.
Bruce {EVangel} Parmenter
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor, RE & AFV newswires
. (originator of the above ASCII art)
===== Undo Petroleum Everywhere
__________________________________________________
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--- End Message ---
--- Begin Message ---
Lee -
Your difficulty finding a DC-DC converter has me wondering if I 'm missing
something and might have a similar problem.
I'm planning to use an isolated DC-DC to power a couple of op-amps and
voltage-to-frequency converters at the traction pack voltage - one each for
pack voltage and battery current - , then run these frequency signals
through opto-isolators to the 12V auxiliary side of things. Then I can
re-convert them into voltages for display in my dash. That way I can avoid
any high voltage at the dash.
And, I'll keep track of battery amp-hours with an LCD counter/display using
the raw current-proportional frequency signal to drive it. My goal is a
simpler, poor-man's version of an E-meter. ( It won't have Peukert
correction, though).
The nice thing about doing this myself ( assuming I can get it to work) is
that if it ever breaks, I'll be able to fix it. And, hopefully I'll learn
something along the way. The whole thing ( including a couple of backlit
digital LCD displays AND some LED bargraphs) will cost about $100.
But, you've got me thinking I might be missing something. The DC-DC I hoped
to use is TI's DCP010505DBP ( Digi-Key sells it) . The whole thing is in
one 14 pin DIP and it has the transformer right in the package. It
converts 5 volts into 1 watt of isolated (but unregulated) +/- 5 volts,
which is more than enough power for my needs.
I'll use a 5V linear voltage regulator to get the 5 volts from my 12V system
to feed the converter. Then, I'll tie the center-tap of the converter's
output to the negative side of my pack.
The spec sheet says it's good for 1 KV of isolation ( UL listed) , and they
say the "barrier capacitance" is 3.8 pF. That's the capacitance across the
transformer, right?
I'm not sure what you mean by "poor isolation". Is your problem that the
resistance between the two sides isn't high enough ( dc leakage)? Or, is the
capacitance across the transformer too high? Or, is the allowable voltage
between the two systems not high enough?
Do you think I'm likely to run into trouble using this DC-DC converter?
Thanks
Phil
From: Lee Hart <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: lee's emeter companion?
Date: Tue, 10 Oct 2006 08:41:08 -0500
[EMAIL PROTECTED] wrote:
Lee,
Any news on the emeter companion?
Still working on it. I ran into a problem with the little DC/DC converter.
The one I initially selected turned out to have poor isolation. In fact
*all* of the small commercial units do! To get guaranteed isolation
requires a larger UL-listed part -- and all the ones I could find were too
big to fit.
So, I designed my own. The key to isolation is the transformer. I've been
testing and evaluating them.
For me, the Companion is part of a 3-board set. I am also designing a
microcontroller board, and a display board. The goal is to hide the E-meter
somewhere, and have my own dash display that simultaneously shows volts,
amps, amphours, and state of charge. The display board is finished, and I'm
working on the micro board while I wait for the transformers to come in to
test.
--
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
_________________________________________________________________
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--- End Message ---
--- Begin Message ---
John, this might make your day - the story about GM and
EV1 on Dutch TV starts with a video segment of WZ taking off
on Woodburn race track as well as your cool interview at your home.
Our friend Mark Mongillo seen there is also a movie star now :-)
I know, you don't read or speak Dutch, just navigate to
http://www.tweevandaag.nl/index.php?module=PX_Story&func=view&cid=2&sid=31174
and click on small video camera icon under first paragraph.
Congrads and enjoy, it's exciting to get such an exposure,
Victor
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
For me, the Companion is part of a 3-board set. I am also designing a
microcontroller board, and a display board. The goal is to hide the
E-meter somewhere, and have my own dash display that simultaneously
shows volts, amps, amphours, and state of charge. The display board is
finished, and I'm working on the micro board while I wait for the
transformers to come in to test.
Excellent Lee, one more option for e-meter replacement. Long due.
What you're designing is very similar to what I've done -
a set of measurement PCB and remote display.
Here are couple of photos of my prototype (I have posed links before):
http://metricmind.com/misc/evision1.jpg
http://metricmind.com/misc/evision2.jpg
Dealing with small DC-DC converters I found that isolation is least
of the problem if you use planar one. Wound off shelf part may save you
$1.50 but you need to watch out for the tr-r manufacturer to follow
up on the iso film quality, creepage distances, etc.
Properly designing planar one proved to be far from trivial task,
and tweaking existing design doesn't work well. If you don't do it
right, cores often overheat, power switch overstressed and reliability
will be low.
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Patrick wrote:
I'm thinking our auxiliary battery is bad. If it were, would it be
possible that the DC/DC continuously trying to charge it could be enough
of a drain cause our traction pack to go down so fast?
Death to All Spammers (gotta agree with that sentiment!) wrote:
One question: What is your dc/dc converter's power output? 300watts is
20-25A, twice that if it's a 600watt version.
--
Sorry for extra post, but I left off part: Even a 600watt converter
should only be drawing ~6A from a 120V pack.
I couldn't find it last night with a flashlight, but this morning I saw
what appeared to be a spec's sticker on the side of the unit about a
half inch from the side of the controller.
If it helps, there's a 30amp fuse on the output, and it's a Sevcon
Generation II. Says Isolated/Regulated 128/12V. Is this enough to go on,
or should I pull the unit so as to read what's on the side?
Also, Roland kindly shared his experiences with similar problems caused
by many short trips. I don't know for sure that our aux. battery is bad
(although I THINK it is), but if it is, I wouldn't think it was for the
same reasons - although I could be wrong of course. When we drive it,
it's usually for 20-30 minutes at a time. This should be long enough to
keep a healthy aux. battery charged, shouldn't it?
2nd question - Anyone have a recommendation for what to replace the aux
battery with? I neglected to check it this AM for what make/model..
*blush*, but visually, it looks like a smallish motorcycle battery sized
thing. After I replace it, I suppose I'll have a better idea of whether
I have another problem as well, right?
Thanks again - the assist is appreciated!
--- End Message ---
--- Begin Message ---
Mike Phillips wrote:
Do we have to have the rs232 option to use your companion?
Yes. However, the point of this project (companion, micro, and display
boards), is to replace the companion with an A/D converter board. The
micro board would be programmed to do the same thing as the E-meter, so
you get the same functionality, but at a lower cost and more
versatility. I suspec the E-meter is just going to "go away" sometime
soon, because it doesn't fit in with Xantrex's marketing plans.
--
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
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
It's been my experience that when you make iberglass thick enough, and
strong enough, to stand up to daily use it ends up being /heavier/ than
steel.
Take for example modern Corvettes; all that fiberglass and the vehicle
weighs over 3,000 lbs.
Well, there's cheap fiberglass and good fiberglass.
Cheap fiberglass is glass mats, produced with a chopper gun, with thick
layers of low-cost polyester resin. It winds up mostly resin, very
thick, heavy, and brittle. This is how you make bathtubs, boats, and
Corvettes.
Good fiberglass is a high strength composite, using carefully woven
fabrics made of fiberglass (or kevlar or carbon fiber), and epoxy
resins. It winds up mostly fiber, much thinner, lighter, more flexible,
and far stronger. Often it is not solid, but uses thin outer layers with
a foam or honeycomb core.
--
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
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--- Begin Message ---
Jukka Järvinen wrote:
The wrong way to manage Lion cells is to cure symptoms.
The cell's behavior can be predicted easily as long you know
the surroundings and environmental conditions.
Rarely do cells fail just by using them. You can easily see the
potentially failing cell by measuring it even before putting it in
the pack.
The most wrong way is to balance with voltage only.
Great advice, Jukka. It actually applies well to all types of cells.
Most balancing systems start out by saying, "We want it as cheap and
simple as possible. What is the *least* we need to do to get by?"
The correct question should be, "What do we need to do to minimize the
cost per mile?" A BMS that adds 20% to the cost of the pack but only
adds 10% to the life is a waste of time. But one that adds 50% and
*doubles* battery life pays for itself in just one pack. The more
expensive system is the better deal.
I have found that voltage is merely a symptom of a balancing problem.
Balancing based solely on voltage won't do much to extend life. The
system needs more data to make better decisions. Temperature, state of
charge, age of the battery, etc.
Then, the BMS needs to be able to *do something* about the imbalance.
Trivial resistive loads, or trickle charging currents may work on new,
well-matched cells But it won't work for cells that are mismatched, old,
at different temperatures, or have other problems. To correct a 20%
difference between cells (not uncommon), you need a BMS that can deliver
20% of a cell's amphour capacity.
Such a BMS is a lot more expensive. But, it eliminates the "weakest
link" problem with large packs (where the weakest cell limits the entire
pack).
--
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
--- End Message ---
--- Begin Message ---
That commercial seriously needs a video rebuttal.
Tagline should be something like:
"Citicar, because the world isn't ending tomorrow."
or
"9 out of 10 scientists agree that driving a Hummer only makes sense
when the world is ending tomorrow."
or
"Things to do when the world is about to end: 1) Tell your family how
much you love them. 2) Make love. 3) Forgive those who have wronged
you. ..... 999,999,999) Waste your time driving a hummer."
or
"With 72 hours left for life on Earth, a Hummer can't do too much more damage."
-Mike
On 10/10/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
For those that didn't see the commercial.....nerdy guy stationed at a remote
observatory sees asteroid will collide with the earth in 72 hours. Reaches
brilliant conclusion, runs from building, hops into his EV (complete with
electric whine) and goes out to buy a GM Hummer. Maybe the marketing guys that
sold this advertising idea to GM realized that this would resonate well with
the beaten down GM management who still believe that replacing the EV1 with the
Hummer was the right choice.
--- End Message ---
--- Begin Message ---
http://www.zqpt.com/english/yysl.asp
oops... was kind of late when I sent that out.
Gadget
I'm wondering what people think about these
> batteries.
> A set of these 150 amphour batteries look like they
> would give a lot of range. It looks like three of
> these would fit in about the same space as an
> Orbital,
> giving aproximately the same voltage. I understand
> that this company is the Chinese partner to Altair
> Nanotechnologies.
>
> Gadget
visit my websites at www.reverendgadget.com, gadgetsworld.org,
leftcoastconversions.com
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--- Begin Message ---
You just did it again - an unsubstantiated off the cuff remark. If you are
going to state otherwise, stop being lazy and cite your sources.
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Death to All Spammers
Sent: October 10, 2006 9:15 AM
To: [email protected]
Subject: Re: Lithium-ion batteries & Valence Group buy ( Michaela EV
Disappointment)
> That is a total peanut gallery cop out. If you are going to cite
something
> - come on, dig it up! What study do you have that says 50%?
>
>
> Try here: http://www.evadc.org/pwrplnt.pdf
>
Sorry, just too lazy and it's been discussed too much in the past for
someone to state coal-fired electricity only makes 5% of an ICE's emissions.
--- End Message ---
--- Begin Message ---
I sent this to a couple of pals from Holland. They loved it.
Very nice piece. Fantastic PR for the EV cause (as usual for JW.)
Keep up the good work.
Bill Dube'
At 12:34 PM 10/10/2006, you wrote:
John, this might make your day - the story about GM and
EV1 on Dutch TV starts with a video segment of WZ taking off
on Woodburn race track as well as your cool interview at your home.
Our friend Mark Mongillo seen there is also a movie star now :-)
I know, you don't read or speak Dutch, just navigate to
http://www.tweevandaag.nl/index.php?module=PX_Story&func=view&cid=2&sid=31174
and click on small video camera icon under first paragraph.
Congrads and enjoy, it's exciting to get such an exposure,
Victor
--- End Message ---
--- Begin Message ---
Phil, I'll comment
Phil Marino wrote:
I'm planning to use an isolated DC-DC to power a couple of op-amps and
voltage-to-frequency converters at the traction pack voltage - one each
for pack voltage and battery current - , then run these frequency
signals through opto-isolators to the 12V auxiliary side of things.
Then I can re-convert them into voltages for display in my dash. That
way I can avoid any high voltage at the dash.
And, I'll keep track of battery amp-hours with an LCD counter/display
using the raw current-proportional frequency signal to drive it. My
goal is a simpler, poor-man's version of an E-meter. ( It won't have
Peukert correction, though).
That is not a problem really.
The nice thing about doing this myself ( assuming I can get it to work)
is that if it ever breaks, I'll be able to fix it. And, hopefully I'll
learn something along the way.
Go for it! This is ultimately the primary reason to do it. You'll be
able to fix it, be proud of it and be far ahead of many who just
types oh keyboards!
But, you've got me thinking I might be missing something. The DC-DC I
hoped to use is TI's DCP010505DBP ( Digi-Key sells it) . The whole
thing is in one 14 pin DIP and it has the transformer right in the
package. It converts 5 volts into 1 watt of isolated (but
unregulated) +/- 5 volts, which is more than enough power for my needs.
I'll use a 5V linear voltage regulator to get the 5 volts from my 12V
system to feed the converter. Then, I'll tie the center-tap of the
converter's output to the negative side of my pack.
TI makes regulated version of it as well, 1W and 2W flavors. Problem
with even low dropout regs is you must feed them with more than
5V in to get 5V out, this means you overstress DC-DC a bit.
With integrated regulator you won't have this issue.
These DC-DCs don't like to be overloaded. They can handle
about 3x of rated output current for a sort while (I've tested),
but don't overload them continuously.
Victor
--- End Message ---
--- Begin Message ---
I think quite a few of us would like to hear more about your fast golf
cart. A golf cart is a good chassis to experiment on and learn about EVs.
I regret that that where I live is not a place where a golf cart could be
operated safely. One could be loaded and hauled on a trailer or truck
to places where it could be run but that would be more trouble than it's
worth.
----- Original Message -----
From: "England Nathan-r25543" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, October 09, 2006 3:36 PM
Subject: Golf Carts, What Can They Teach?
I would first like to thank all the folks who have helped with EV
questions over the years. I used a golf cart as a platform to teach
myself basic EV principals without the full price up front. If I could
not make a golf cart work there was no sense in me trying a full size
EV. I am still learning but the golf cart has taught me more than I
could have imagined. I did not talk much about this project as most EV
folks did not seem to like the idea of golf carts in the same list with
EVs. I can understand not wanting to be associated with a little 15 MPH
vehicle myself.
The golf cart was entered into a competition for golf carts last June in
Richmond, Kentucky, I wanted to see if all these years of number
crunching and testing was teaching me anything or did I just think I was
doing good. Four out of five trophies later I figured maybe I was doing
something right. My golf cart had the quickest 1/8 mile time of any cart
there, gas or electric. I beat a modified 1000cc gas rig also. The event
obviously is not held for environmental reasons but for folks who like
playing with golf carts. What happened was you had a bunch of folks that
normally had no exposure to the power of electric vehicles above a 48
volt golf cart see what kind of performance electric is capable of. I
even had some die-hard ICE folks come over and congratulate me on my
wins... this did not mean they were ready to quit playing with their gas
rigs just yet but they will never forget that day and what the power of
an electric golf cart did. The kids were asking questions like crazy and
thought it was very cool, I had many questions about making an electric
racecar. I pointed out that NEDRA has already been formed and gave them
web sites to vist.
So why am I printing this now? The president of the electric auto
association in Phoenix saw my work on a golf cart forum and asked me to
give a brief overview at their October meeting last Saturday. If EV
folks want to periodically hear about an electric golf cart doing 8.7
seconds in the 1/8 mile and catching the attention of many non-EV folks
I will be happy to share. I promise I will not talk golf carts but on
rare occasions here.
Specs:
1986 Club Car
120 volt battery pack
Electronic control
Golf cart motor but not stock.
27" Mud tires on 12" rims
Rear gear 12.44:1
Top speed 50 MPH.... yes that little 6" motor was close to 8000 RPM.
Thanks,
Nate
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--- Begin Message ---
Patrick,
Your aux battery is NOT the reason you are sagging
your pack to 60V at a 200+ draw.
If I read your post about the specs right: this battery
has 475 Watts per Cell for 15 min until at 1.67V per cell
at room temp.
This means about 250A for 15 min or 62Ah at about 2C rate.
Now that shold give you more than 11 miles / 27 Ah.
So the only other possiblity if you have no loose
connections or other high resistance is that you have
hurt one or more batteries during earlier runs
OR that you are chronically under-charging the batteries.
You mentioned 133V without qualifying if this was DURING
charge (end voltage) or after charging.
If it was after charging, your charged battery voltage is OK.
If this was during charging, you are not fully charging them.
Even if they are fully charged NOW, an earlier too-deep
discharge can have damaged batteries and I also see a too
deep sag in my batteries now I have 3 that have been taken
down too deep earlier.
Can you measure all 10 battery voltages while they are
under a constant load?
The easiest way is to take a wire of several tens of feet,
preferably 100 and connect that across the 12V battery you
are measuring and see the voltage drop. Take a reading after
a defined time, for example 15 sec and write that down for
each battery.
You may find that one or more are 1 or 2 volts lower than
the others.
Preferably do this measurement after you have driven, so
the bad batteries will show up worse.
Your 12V aux battery may be weak, but tat has nothing to
do with your pack sagging - the load is insignificant
unless you charge once a week and leave the DC/DC on
always, then it accumulates. But in your case the DC/DC
seems fine, your aux battery may need a bit more juice
but seems OK otherwise, I guess the marine batteries
have been abused too badly. Your measurements should
provide more data.
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Patrick Clarke
Sent: Tuesday, October 10, 2006 10:00 AM
To: EV List
Subject: Re: Bad aux battery affects Voltage Sag?
Patrick wrote:
>> I'm thinking our auxiliary battery is bad. If it were, would it be
>> possible that the DC/DC continuously trying to charge it could be enough
>> of a drain cause our traction pack to go down so fast?
Death to All Spammers (gotta agree with that sentiment!) wrote:
> One question: What is your dc/dc converter's power output? 300watts is
> 20-25A, twice that if it's a 600watt version.
> --
> Sorry for extra post, but I left off part: Even a 600watt converter
> should only be drawing ~6A from a 120V pack.
I couldn't find it last night with a flashlight, but this morning I saw
what appeared to be a spec's sticker on the side of the unit about a
half inch from the side of the controller.
If it helps, there's a 30amp fuse on the output, and it's a Sevcon
Generation II. Says Isolated/Regulated 128/12V. Is this enough to go on,
or should I pull the unit so as to read what's on the side?
Also, Roland kindly shared his experiences with similar problems caused
by many short trips. I don't know for sure that our aux. battery is bad
(although I THINK it is), but if it is, I wouldn't think it was for the
same reasons - although I could be wrong of course. When we drive it,
it's usually for 20-30 minutes at a time. This should be long enough to
keep a healthy aux. battery charged, shouldn't it?
2nd question - Anyone have a recommendation for what to replace the aux
battery with? I neglected to check it this AM for what make/model..
*blush*, but visually, it looks like a smallish motorcycle battery sized
thing. After I replace it, I suppose I'll have a better idea of whether
I have another problem as well, right?
Thanks again - the assist is appreciated!
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