EV Digest 5698
Topics covered in this issue include:
1) RE: Rogue battery in string
by Cor van de Water <[EMAIL PROTECTED]>
2) Re: Goldie Lives!
by "John Westlund" <[EMAIL PROTECTED]>
3) Solectrii - ps
by Seth Rothenberg <[EMAIL PROTECTED]>
4) Re: AC, DC, BLDC Motors and controllers
by Jack Murray <[EMAIL PROTECTED]>
5) Re: A123 Specs (was: Rich Rudman's PHEV project (?))
by "Philippe Borges" <[EMAIL PROTECTED]>
6) WKTEC in Australia
by "Mark Fowler" <[EMAIL PROTECTED]>
7) Re: Solectrii
by "Roland Wiench" <[EMAIL PROTECTED]>
8) re: Solectria A/C compressor anyone?
by jeff <[EMAIL PROTECTED]>
9) Re: Interest in a Nissan / Mazda 626 Conversion
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
10) Interest in a Nissan / Mazda 626 Conversion
by "Paul Francis" <[EMAIL PROTECTED]>
11) Re: 94 US Electricar S-10 (battery question)
by Mike Phillips <[EMAIL PROTECTED]>
12) Re: Want to build a sporty EV, AC is feasible too.
by "Mike Phillips" <[EMAIL PROTECTED]>
13) Re: Solectrii - ps
by "Peter VanDerWal" <[EMAIL PROTECTED]>
14) Re: Solectria A/C compressor anyone? A bit of background
by "Michaela Merz" <[EMAIL PROTECTED]>
15) Re: Want to build a sporty EV, AC is feasible too.
by Mike Phillips <[EMAIL PROTECTED]>
16) Re: A123 Specs (was: Rich Rudman's PHEV project (?))
by Mike Phillips <[EMAIL PROTECTED]>
17) Re: Solectrii - ps
by Doug Weathers <[EMAIL PROTECTED]>
18) RE: Rogue battery in string
by Steve Condie <[EMAIL PROTECTED]>
19) Re: Solectria A/C compressor anyone?
by Jude Anthony <[EMAIL PROTECTED]>
20) Re: AC, DC, BLDC Motors and controllers
by "Peter VanDerWal" <[EMAIL PROTECTED]>
21) RE: Solectria A/C compressor anyone? A bit of background
by "Roger Stockton" <[EMAIL PROTECTED]>
22) Re: Interest in a Nissan / Mazda 626 Conversion
by Doug Weathers <[EMAIL PROTECTED]>
23) Re: Want to build a sporty EV, AC is feasible too.
by Steve Lacy <[EMAIL PROTECTED]>
24) RE: Rogue battery in string
by "Roger Stockton" <[EMAIL PROTECTED]>
--- Begin Message ---
Hi Steve,
Can you verify if there is anything different in the
environment of this battery, for example is it hotter
or colder than the other batteries; restricted air or
more air flow, at the edge of a battery box, or
anything else that can impact it?
Did you check its regulator to conduct at the same voltage
as the other regs?
In case it really is this one battery that is off
(and you may be able to validate it by charging the
others until they show the same voltage as this one
or partially DIScharging this one and then charging
the entire string until full and test if it drops
its voltage before any of the others or if it does
stay in sync from then on) and you need to replace
this one battery: I ordered 27 for my 26 pack to
have a spare and as of now they all seem to be
very well balanced, so once you have tested this
battery and want to replace it, I can sell you
my spare (it has the same production date as all
the others you and I have).
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 Steve Condie
Sent: Saturday, July 29, 2006 1:01 PM
To: EV List
Subject: Rogue battery in string
As I've mentioned before, I've got Lee Hart's zener-lamp shunt regulators on
my pack of 13 UB12110 batteries. Having the bulbs provides a visible
feedback on the voltage of each of the batteries once they get to the 13-8 -
15 volt range. I was surprised to see the variations in how batteries come
up to voltage - some start fast then taper off; others start slow but hit a
higher eventual voltage in the string. Very interesting.
I've been careful about charging to too high a voltage because I suspect
that the cheap AGM's wouldn't like that too much. But lately I've noticed
that one of my batteries - #13, the extreme + end one - has been running
off and leaving the rest behind once I get into Z-reg range.. It quickly
spiked above 15.3 volts while the rest were just at the 13.9 - 14.2 volt
range. I turned off the charger. When I tested its individual voltage with
my meter I saw the unfortunately familar flash from the Z-reg bulb as it
burnt out. I replaced the bulb, and tried again the next day. Same thing
-the #13 battery spiked quickly a volt or more above all the rest, so I had
to turn the charger down to the point where the #13 Z-reg was glowing, with
the #13 battery cooking along at 14.35 or so, while the rest are all around
13.6. I'm sure there's an explanation for this, but I don't remember seeing
it here. Anyone want to help me understand this?
---------------------------------
Do you Yahoo!?
Next-gen email? Have it all with the all-new Yahoo! Mail Beta.
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
>It would be nice if I had some nasty trick done to the
>motor... but it's the same old 8 incher...sigh....
Forget the motor. You need some suspension tweaks. There's
no reason your car shouldn't be running low 15s or quicker
as it is other than the fact that it's FWD and can't get
shit for traction.
--- End Message ---
--- Begin Message ---
I forgot - voltage dropped 7 volts from
173 to 166 in the time we drove it.
The Amp-hour meter registerd about 13 KWh.
I wonder if that extra information says anything
about the batteries. BTW, the Amp/Volt meter
in this car is not working...I can't think
what sound is the opposite of ChaChing!
Thanks
Seth
--- End Message ---
--- Begin Message ---
Maybe I misunderstand, but isn't an AC motor different in that it uses
the negative voltage to induce a charge in the rotor that then is
attracted to the positive voltage, so the AC voltage swing is used,
wherease the BLDC has the permanent magnet rotor and only needs the
positive voltage?
Very nice paper on the brushless controller! thanks.
I also use the MSP430.
The constant switching in the FETs does create a lot of resistance and
heat, we see this in the R/C cars, a brushless controllers will overheat
before a brushed ones does.
Jack
Arthur W. Matteson wrote:
Jack Wrote:
A significant issue is the controller and its losses. A DC controller
is very simple, a BLDC controller is not, I suspect an AC controller is
even more complicated.
The inverter for a "brushless-DC" - which is often called permanent
magnet AC (PMAC) because of its winding pattern, depending on which you
have - has basically the same inverter as an AC induction motor.
Sometimes the BLDC/PMAC control algorithm is just a bit more complicated
since it needs to know absolute position. If you use field-oriented
control, you only need to change one number in a design with a position
sensor: field current is zero for a motor with a magnet.
Wayne wrote:
I have several stepper motors very similar to that for a CNC project
of my own.
I just got my $4.95 motor to turn an hour ago. It's pretty amazing, but
it's very hard to start correctly (from a stalled shaft).
Here is an application note I wrote on the topic:
http://www.egr.msu.edu/~mattes12/appnote3.pdf
- Arthur
--- End Message ---
--- Begin Message ---
I play a little with multi cell lithium pack design and resistance
connection quality is a major argument.
Soldering or welding ? that is the question !
Some say soldering is better (wider contact surface) others say welding is
better (can't desolder from heating)
i'm still searching ...but soldering is easier and explain RC community
choice i suppose.
cordialement,
Philippe
Et si le pot d'échappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les véhicules électriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, July 30, 2006 1:18 AM
Subject: A123 Specs (was: Rich Rudman's PHEV project (?))
> I have tortured A123 cells on the bench and on the track. They meet
> or exceed the spec sheet in every way I have tested.
>
> A lot depends on how you connect to them, by the way. You
> must weld tabs to the ends with very pricey high-current equipment.
> If you attempt to draw the max power from them with pressure contacts
> or improperly welded tabs, (or other less-than-optimal connections)
> you will not get what you were hoping for.
>
> The A123 folks know this and supply their evaluation cells
> with double tabs on each end. These cells put out a lot of current,
> and the tabs must be up to the task, or the tabs will be the weakest link.
>
> Bill Dube'
>
> At 03:45 PM 7/29/2006, you wrote:
> >RC fellows disagree: A123 are not as good as claimed though still better
for
> >their usage than NIMH and 3/4 time than lipoly.
> >
> >cordialement,
> >Philippe
>
--- End Message ---
--- Begin Message ---
Hi all,
I've been checking out when WKTEC is going to show in Australia.
According to the Greater Union web site,
http://www.greaterunion.com.au/movies/movie.asp?movie=6114
It opens on Thurs, 10th of August.
So, I called my local GU cinema to check that they would be showing it.
Unfortunately, they were not planning to show it.
Ok, so which cinemas were going to show it?
After checking with the head office, it seems that GU decided not to
import the movie at all.
A quick check with Hoyts Cinemas and Reading Cinemas showed that neither
of them had any plans to show the movie in Australia.
So, does anyone out there know if ANYONE is planning to show WKTEC in
Aus?
The Sydney AEVA guys were pretty keen to turn up to the premiere,
potentially manning an EV info booth or showing off their cars.
Does anyone know if Chris Paine is planning to head to Aus to show his
movie?
(Can't imagine why, based on the interest shown so far...)
Mark
--- End Message ---
--- Begin Message ---
Hello Seth,
If the battery pack is 13 each 12-volts then the battery pack is a 156 volt
pack.
If the charge voltage is 173 volts then this is 13.3 volts per battery which
is good.
After driving 1/2 hour results in a 166 volt battery pack or 12.76 volts is
still good.
Battery sag is normally a voltage drop to below the battery pack under load,
and than comes back up after the load is off.
The minimum voltage drop while applying a load is to about 11 volts per
battery or 143 volts for a 156 battery pack.
Driving a EV until the battery pack is at 50% discharge, the voltage should
be about or above 12 volts per battery or 156 volts after load comes off or
open circuit voltage.
State of Charge as related to specific gravity and open circuit voltage.
Percentage Specific Gravity Open Circuit
of at 80F Voltage
Charge
100 1.277 12.73
90 1.258 12.62
80 1.238 12.50
70 1.217 12.37
60 1.195 12.24
50 1.172 12.10
40 1.148 11.96
30 1.124 11.81
20 1.098 11.66
10 1.073 11.51
Roland
----- Original Message -----
From: "Seth Rothenberg" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, July 29, 2006 10:12 PM
Subject: Solectrii
>
> The cat's out of the bag (well it wasn't a *secret*,
> I just wasn't publicizing what I knew until I knew what it meant :-)
>
> It's funny, someone gives you information, and it takes a while
> until someone else gives you the information till it sinks in.
>
> I whined to my friend about my DMV worries, so he said
> call this lawyer I know in Morristown, brokers cars too...
> I call him, he said "Another NUT with an EV?"
> Then he told me to forget the Saturn, take the EV parts
> and part it out....But I asked who the first nut was,
> and got his name and number...he actually used to live
> in Passaic, and we talked abit, and he told me about
> the Transoptions deal, and I hit their website, etc....
>
> Someone posted Friday about Solectrias that transoptions is
> selling. A Transportation solutions company was
> operating a lease program for Station cars for Corporate
> customers. Their customer is moving, and the cars are on
> the block.
>
> Well, I had already been working on setting up a testdrive,
> so FRIDAY I got a test ride in the one Solectria Force that they
> said doesn't need work...and I think they are a bit mistaken
> (not alot :-).
>
> I asked if I could do one or two tests before the ride.
> "Sure, if you know what you're doing"...So I pop the hood,
> say, gotta make this look like I know what I'm doing....
> Hey, an Anderson Connector, cool...big box (controller ?:-)
> Motor, so the cable with the Anderson must be Pack Voltage!
>
> Pack was 173V before the drive. That's all I checked.
> It was NOT fresh off charge, it had been driven about 1 mi.
>
> They didn't let me drive due to insurance
> (OK, but the offered price will be lowered)
> but John drove for a while, hit the freeway, + stop n go...
>
> Pack Voltage after 1/2 hour was 166. Seven volt drop.
> Quick math 13 *12 = 132...13*13 = 169, so it is sagging a bit,
> but not to the danger zone....Is this pack bad?
>
> Although this is the car with nothing wrong with it,
> it does seem to have a vibration during regen.
> I *think* the vibration went away w/Regen off.
> I can ask. Actually, if that's NOT the problem, I know
> people here who build race cars, they'll know how
> to fix other problems - I can think of a few possible causes.
>
> They also have for sale another one that has
> an old, worn battery pack....and another one
> that has a bad charger. That's my favorite one,
> because I heard that Rich makes good chargers....
> I asked if the car has been sitting without a charger,
> and they conceded that it probably needs a new pack
> by this time...cool, I could use the old pack
> for the Saturn :-)
>
> (Bob Rice got a preview on this topic,
> I'm kind of leaning toward his quiet suggestion :-)
>
>
> BTW, in theory, the one that is "running well"
> I could actually drive home, since it's just 24 miles,
> and I could even find a route that's not highway
> if need be.
>
>
> This is the car for which I was thinking I
> would get NiCADs...and I read Tom's Web site on DIY
> NiCAD Solectria, I am still looking for more info from
> a more DIY-type...Solectria is gone (GM? Chevron?)...
> especially, re: air-cooled NiCADs.
>
> My friend the Rocket Scientist (another Bob) had nice
> things to say about NiCADs, and he's someone who actually
> knows how batteries work...really, inside.
> (He's not really an EV'er except for his kids PV car)
>
> Any thoughts? What do people buy Solectrias for
> BEFORE fix-up? ( I have seen the ebay auctions after fixup :-)
> Morristown saves me a few hundred bux on transportation.
>
> Thanks
> Seth
> PS Inspection for Solectrias is...in Morristown,
> near where the vehicles live now :-)
>
>
--- End Message ---
--- Begin Message ---
I was looking into finding a 2004 prius AC compressor, I understand it
is 288v electric.
--- End Message ---
--- Begin Message ---
In your area cars rust as you look at them. I'd be suprised a 626 would
last. I had one. Very good car. Put 205k on it and got it when it had
180k. When running well it got 35mpg at 75mph. It is light at about 2200
pounds curb. Maybe less. Had a 2L motor & could get to 100 mph quick. If
the body is sound it will make a good EV for family use. It has a large
trunk & lots of room under the hood. Of course if you could get to
California you can find a rust free car for peanuts. Lawrence Rhodes....
----- Original Message -----
From: "Paul Francis" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, July 29, 2006 8:02 PM
Subject: Interest in a Nissan / Mazda 626 Conversion
> Hi,
> This is Paul.
> Joined to read up on conversions to Mazda 626 ( 1986 )
> 5 speed currently a 4 cylinder , 4 passenger car
> and Nissan Z Cars, 240-260-280 - 300 ZX type cars (1974 - 87 ) 5 speed
currently a 6 cylinder 2 passenger car. Would like to make contact with Tom
True and Don Crabtree after reading Make-Zine Article on Datsun Z
Conversion.
> A conversion may be impractical for this northern Pennsylvania climate
area, but the oil companies need our feedback the other 8-9 months of the
year
>
> Paul Francis,
> Erie, PA
>
--- End Message ---
--- Begin Message ---
LR,
Yes, Could not agree more with you. The Mazda in my garage is rust free
and has 120,000 miles and did return good fuel mileage. This area uses a
great deal of road salt. The cars I own have been garaged in winter when I
drive a small pickup truck for daily use.
Regards,
Paul
----- Original Message -----
From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, July 30, 2006 10:48 AM
Subject: Re: Interest in a Nissan / Mazda 626 Conversion
> In your area cars rust as you look at them. I'd be suprised a 626 would
> last. I had one. Very good car. Put 205k on it and got it when it had
180k. When running well it got 35mpg at 75mph. It is light at about 2200
pounds curb. Maybe less. Had a 2L motor & could get to 100 mph quick. If
the body is sound it will make a good EV for family use. It has a large
trunk & lots of room under the hood. Of course if you could get to
California you can find a rust free car for peanuts. Lawrence Rhodes....
>
> > Hi,
> > This is Paul.
> > Joined to read up on conversions to Mazda 626 ( 1986 ) 5 speed
currently a 4 cylinder , 4 passenger car
and Nissan Z Cars, 240-260-280 - 300 ZX type cars (1974 - 87 ) 5 speed
currently a 6 cylinder 2 passenger car.
> > A conversion may be impractical for this northern Pennsylvania
climate
> area, but the oil companies need our feedback the other 8-9 months of the
> year
> >
> > Paul Francis,
> > Erie, PA
> >
>
>
--- End Message ---
--- Begin Message ---
Marc,
See my responses below.
--- Marc Michon <[EMAIL PROTECTED]> wrote:
> to: Mike phillips
> i just got an USE 1994 s-10
How many miles does it have on it?
> i can't take off the bed till i make a gate in back yard/alley
> to get truck in back yard its too hot here this week 115
> to be digging fencepost holes
> so its not charging
> i'm looking for the charger
> is it under the bed??
The charger is in the large aluminum "Dolphin" box under the hood.
> ? controller for charger in inverter box?
> can't get to till above work is done to take bed off
> plug cord goes into tool box in bed
> bypasses, transformer thats in tool box for drop voltage 240 to 208v?
Only charge from 120vac for now. There are problems with USE vehicles
charging on 240vac. The transformer that the factory installed reduces
the voltage from 240 to 208. That makes it safer. Only charge on 240vac
IF you have the transformer properly installed!!
> behind seat is a transducer
> plug in 240v read no amps at wires in transformer
> no voltage or amps at transduceer
> hear a click under bed, unplug clicks again
Sounds like main contactors engaging.
> guy i bought from knows less than me
> said charged inermintly if left on for a week charged up
> at shop,took home wouldn't charge overnight
> he said has deka battries in i think
> i left his shop,had 390v drove home 12 miles now at 330v
> so if has 26 battries i'm at 12.69 v per battery?
330v is very high for a 26 battery pack after driving on the freeway.
They must be brand new. When was the pack reading 390v? Was it right
off of the charger? For 26 batterys 390v is way too high for good pack
life. What kind of instrument are you reading the voltage on?
> ok to sit for a while?
> with out hurting batteries?
Leave the batterys fully charged when the truck is going to sit for a
while.
> is very nice truck first EV i have driven on freeway!!!!
> at 60 mph and70 mph wowie!!
> thanks
> Marco Michon Fresno,[EMAIL PROTECTED]
I'm in San Jose near Reid Hillview airport.
Mike
Here's to the crazy ones.
The misfits.
The rebels.
The troublemakers.
The round pegs in the square holes.
The ones who see things differently
The ones that change the world!!
www.RotorDesign.com
--- End Message ---
--- Begin Message ---
The problem with your "recommendation" is that you would be forced to
run a lead acid pack to get the 2000+ amps to make it go fast. Lion
and Nimh batts can't do that. So the huge amount of added lead acid
weight is not a speed enhancement secret the last time I checked ;)
Mike
--- In [EMAIL PROTECTED], "Death to All Spammers"
<[EMAIL PROTECTED]> wrote:
>
> > Happily. http://www.wrightspeed.com/x1.html It has done 11.5 seconds.
> >
> > The TZero hit low 13's with lead acid. With lithium it's a 12's
car due
> > to losing around 500lbs in lead weight. The only reason the Tzero
can't
> > do 11's is because of gearing. The way it's geared the motor has to be
> > electronically limited to 90 mph. Add another gear with the same
150 kw
> > and it hits 11's easily. The X1 has the same set up. The X1 and the
> > T-zero have the distinct disadvantage of not having slicks. That would
> > rocket the X1 into the 10's and under 2.9 second 0-60 times so
said Ian
> > Wright to me personally. All on 165kw. Don't forget they get their
> > power from the volts too. 300-400 volts times 700 amps is up to 280kw
> > peak, not sustained. I've personally watched the 100kw version sustain
> > 400 amps at 336 volts. That's 135kw. These numbers are easily altered
> > via the software.
> >
>
> Just think how much quicker they'd be with an AdvDC motor and a Z2K!
>
--- End Message ---
--- Begin Message ---
> ...I can't think
> what sound is the opposite of ChaChing!
Hmm ChaPlunk ???
--
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 ---
I though I give you a bit of background about my a/c activities.
I have a '94 144V S-10 and the previous owner removed all a/c related
parts. Unfortunately space is limited, in the engine compartement as well
as in the cab (Not a crew cab).
I tried the following:
A cooler in the bed of the truck, filled with 20pounds of ice, a bilge
pump circulates the cold water into the cab, a blower blows air over an
oil-cooler type 'evaporator' - Result: Air is about 60 degrees for 20
Minutes. Nice if the air stream blows right into your face. But not really
the thing as ice is expensive and not practical. Frozen bottles (I tried
different sizes and shapes) are no alternative as they won't give enough
cooling to the water.
Use a 2000 BTU 'Pet Cool' electric a/c. I cut the copper between
condensing unit and evaporator, put the condensing unit in the bed of the
truck and run the pipes back into the cab, resoldered with the evaporater.
Result: 2000 BTUs is not enough to feel a difference in temperature.
I thought about a bigger a/c in terms of a 5000 BTU window unit, but my
inverter is most likely unable to handle that and - I don't want to have a
huge chunk of a/c sitting in the bed of the truck.
Back to the drawing board. I think, the only way to go is to restore the
original S-10 a/c. The DENSO and other electric compressors either run
with a pretty complicated voltage and/or need some special ester in
addition to, or in combination with the refrigerant. I don't know if those
refrigerants would be usable with the rest of the S10's a/c system.
Solectria has (had) 144V compressors, actually normal units, belted to a
small motor. I don't have the mechanical knowledge to 'mate' a motor to an
compressor myself. The examples listed in reply to my original posting
were interesting, though I would have a hard time finding a spot in my
truck to put big motors like that.
Thanks for your insights.
Michaela
--- End Message ---
--- Begin Message ---
>
> The consensus on this list seems to be that DC is better for
> performance.
That's because it's a DC list :)
Mike
--- End Message ---
--- Begin Message ---
In the R/C community homebrewed is soldered, factory purchased is
welded.
Either works if you do it right. I've soldered hundreds. If I had to
make enough EV class modules I would work very hard on perfecting
welding. I've welded .002" wire to another part, so how hard could it
be to weld a flat tab to a flat surface?
The one advantage I've seen many times in the field is that when a
soldered pack gets shorted so it overheats, the solder joints melt and
open circuit the pack.
Mike
--- Philippe Borges <[EMAIL PROTECTED]> wrote:
> I play a little with multi cell lithium pack design and resistance
> connection quality is a major argument.
> Soldering or welding ? that is the question !
> Some say soldering is better (wider contact surface) others say
> welding is
> better (can't desolder from heating)
> i'm still searching ...but soldering is easier and explain RC
> community
> choice i suppose.
>
> cordialement,
> Philippe
>
> Et si le pot d'échappement sortait au centre du volant ?
> quel carburant choisiriez-vous ?
> http://vehiculeselectriques.free.fr
> Forum de discussion sur les véhicules électriques
> http://vehiculeselectriques.free.fr/Forum/index.php
>
>
> ----- Original Message -----
> From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Sunday, July 30, 2006 1:18 AM
> Subject: A123 Specs (was: Rich Rudman's PHEV project (?))
>
>
> > I have tortured A123 cells on the bench and on the track. They meet
> > or exceed the spec sheet in every way I have tested.
> >
> > A lot depends on how you connect to them, by the way. You
> > must weld tabs to the ends with very pricey high-current equipment.
> > If you attempt to draw the max power from them with pressure
> contacts
> > or improperly welded tabs, (or other less-than-optimal connections)
> > you will not get what you were hoping for.
> >
> > The A123 folks know this and supply their evaluation cells
> > with double tabs on each end. These cells put out a lot of current,
> > and the tabs must be up to the task, or the tabs will be the
> weakest link.
> >
> > Bill Dube'
> >
> > At 03:45 PM 7/29/2006, you wrote:
> > >RC fellows disagree: A123 are not as good as claimed though still
> better
> for
> > >their usage than NIMH and 3/4 time than lipoly.
> > >
> > >cordialement,
> > >Philippe
> >
>
>
--- End Message ---
--- Begin Message ---
On Jul 29, 2006, at 10:48 PM, Seth Rothenberg wrote:
BTW, the Amp/Volt meter
in this car is not working...I can't think
what sound is the opposite of ChaChing!
How about ChaChina?
<http://stores.ebay.com/MadeinCHN2006>
Digital voltmeters and ammeters for very low prices. Recommended by a
couple of other list members - I haven't ordered from them yet.
--
Doug Weathers
Las Cruces, NM, USA
<http://learn-something.blogsite.org/>
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--- Begin Message ---
Thanks Cor. If the problem persists I will take you up on that. All of my
UB's are in one battery box in the front part of the bed of my truck. #13 is
at the end of the string, and has other batteries on two sides and the
epoxy-coated plywood box on two others - a status that several of the other
batteries share. All of my batteries have 1" air gap between them and the
other batteries anytime there is a voltage differential between them - that is,
batteries in the string which are end to end and connected at the nearest posts
are touching, all others are separated by a gap. They all sit in a bed of
baking soda to absorb and neutralize any seepage as Rolan Wiench suggests
(I've seen that seepage with SLA batteries in scooters before.) So I don't see
anything in the environment of the batteries which should affect #13 any
different from any other.
I left the pack off charge overnight. #13 is at 13.3V. The others range from
13.16 to 13.26, with most sitting close to 13.2. I guess what puzzles me most
is the fact that the one battery has higher voltage and hogs the current when
charging. Once it ran up to 16V before before I shut the charger down while
the rest were at 13.8 or so. The opposite I would understand better. I'm also
a little mystified by the Z-reg bulb burning out when I touched the reg heat
sinks with my voltage meter probes. Did that cause a spike of some kind
through the Z-reg wires? If so, why?
I'm thinking of doing what you suggest, and discharging #13 or charging the
rest up to equalize. I may take a run first to take the batteries down a
little first though. Of course, Cor - my batteries are being subjected to much
harsher treatment than yours. With just 13 of them, I'm pulling 300 amps
regularly on acceleration, and 400 from time to time. I've also recently taken
a couple of range testing jaunts of around 30 miles which I figure consumed 60
amp-hours or so, which is, depending on how you look at it, somewhere between
60 and 80% DOD. So I am pushing the UB's pretty hard, and am not surprised to
be finding weak points. I'm just a little confused at how that has manifested.
Cor van de Water <[EMAIL PROTECTED]> wrote: Hi Steve,
Can you verify if there is anything different in the
environment of this battery, for example is it hotter
or colder than the other batteries; restricted air or
more air flow, at the edge of a battery box, or
anything else that can impact it?
Did you check its regulator to conduct at the same voltage
as the other regs?
In case it really is this one battery that is off
(and you may be able to validate it by charging the
others until they show the same voltage as this one
or partially DIScharging this one and then charging
the entire string until full and test if it drops
its voltage before any of the others or if it does
stay in sync from then on) and you need to replace
this one battery: I ordered 27 for my 26 pack to
have a spare and as of now they all seem to be
very well balanced, so once you have tested this
battery and want to replace it, I can sell you
my spare (it has the same production date as all
the others you and I have).
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 Steve Condie
Sent: Saturday, July 29, 2006 1:01 PM
To: EV List
Subject: Rogue battery in string
As I've mentioned before, I've got Lee Hart's zener-lamp shunt regulators on
my pack of 13 UB12110 batteries. Having the bulbs provides a visible
feedback on the voltage of each of the batteries once they get to the 13-8 -
15 volt range. I was surprised to see the variations in how batteries come
up to voltage - some start fast then taper off; others start slow but hit a
higher eventual voltage in the string. Very interesting.
I've been careful about charging to too high a voltage because I suspect
that the cheap AGM's wouldn't like that too much. But lately I've noticed
that one of my batteries - #13, the extreme + end one - has been running
off and leaving the rest behind once I get into Z-reg range.. It quickly
spiked above 15.3 volts while the rest were just at the 13.9 - 14.2 volt
range. I turned off the charger. When I tested its individual voltage with
my meter I saw the unfortunately familar flash from the Z-reg bulb as it
burnt out. I replaced the bulb, and tried again the next day. Same thing
-the #13 battery spiked quickly a volt or more above all the rest, so I had
to turn the charger down to the point where the #13 Z-reg was glowing, with
the #13 battery cooking along at 14.35 or so, while the rest are all around
13.6. I'm sure there's an explanation for this, but I don't remember seeing
it here. Anyone want to help me understand this?
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--- End Message ---
--- Begin Message ---
Doug Weathers wrote:
I keep reading a persistent rumor that it's possible to use treadmill
motors to run a standard automotive A/C compressor.
I've tried that using a 1120VDC 3600RPM 2.0HP motor from sciplus.com,
rated at 14.2A. On the first test, it ran so fast the brushes glowed
orange; my wife panicked and made me turn it off. I haven't tried it
again since.
Jude
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--- Begin Message ---
Sounds like you did misunderstand, somewhat. As folks frequently point
out, nearly all motors are AC internally. The difference, in this case,
is naming convention.
The major difference between BLDC and AC is the shape of the wave form.
Technically AC should be a sinewave whereas BLDC is normally a trapazoid
shaped wave. The motors are nearly identical, except they are typically
optimized for the type of wave form.
The first type of motor you were describing is called an induction motor.
These are popular in appliances, etc. because they are cheap and easy to
manufacture. You can have a BLDC induction motor, though I can't think of
any off hand.
BLDC often use a Permanent Magnet for the field. AC motors can also use
Permanent Magnets, these are usually called Synchronous AC motors.
Just to make things interesting, there is another type of motor that
doesn't use either Permanent Magnets or would fields. The rotor is simply
a chunk of iron or steel. It's called a reluctance motor. These can also
be optimized for either an sinewave or a trapazoid (perhaps even other
wave shapes).
Finally, I started by mentioning that most motors are AC motors
internally. There is at least one motor that is a pure DC motor. It's
called a homopolar motor (google it for more info). Because these run on
very low voltag at relatively high current, they are not generally very
usefull and are easily missunderstood. This, as well as measurement
errors, often leads to mistaken claims about over-unity.
> Maybe I misunderstand, but isn't an AC motor different in that it uses
> the negative voltage to induce a charge in the rotor that then is
> attracted to the positive voltage, so the AC voltage swing is used,
> wherease the BLDC has the permanent magnet rotor and only needs the
> positive voltage?
>
> Very nice paper on the brushless controller! thanks.
> I also use the MSP430.
> The constant switching in the FETs does create a lot of resistance and
> heat, we see this in the R/C cars, a brushless controllers will overheat
> before a brushed ones does.
>
> Jack
>
> Arthur W. Matteson wrote:
>>>Jack Wrote:
>>>A significant issue is the controller and its losses. A DC controller
>>>is very simple, a BLDC controller is not, I suspect an AC controller is
>>>even more complicated.
>>
>>
>> The inverter for a "brushless-DC" - which is often called permanent
>> magnet AC (PMAC) because of its winding pattern, depending on which you
>> have - has basically the same inverter as an AC induction motor.
>> Sometimes the BLDC/PMAC control algorithm is just a bit more complicated
>> since it needs to know absolute position. If you use field-oriented
>> control, you only need to change one number in a design with a position
>> sensor: field current is zero for a motor with a magnet.
>>
>>
>>
>>>Wayne wrote:
>>>
>>>>I have several stepper motors very similar to that for a CNC project
>>>>of my own.
>>>
>>
>> I just got my $4.95 motor to turn an hour ago. It's pretty amazing, but
>> it's very hard to start correctly (from a stalled shaft).
>>
>>
>> Here is an application note I wrote on the topic:
>>
>> http://www.egr.msu.edu/~mattes12/appnote3.pdf
>>
>>
>> - Arthur
>>
>>
>
>
--
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 ---
Michaela Merz wrote:
> Back to the drawing board. I think, the only way to go is to
> restore the original S-10 a/c.
Have you considered using an off-the-shelf RV airconditioning unit?
For instance, the AirV from Carrier:
<http://www.airv.com/Files/AirV/Local/US-en/customer_service/10896.pdf>
A quick Google turns these 13,500BTU self-contained roof mount units for
about $400-500. The downside to using one of these is that they run on
115VAC, so you'd need to provide an inverter of about 2kW rating (the
air con is spec'd to consume just under 1500W).
However, if you browse Carrier's website and check out the "split
units", I notice these are available to run from either 12VDC or 24VDC,
and consume about 20A @ 12V:
<http://www.transportaircon.carrier.com/details/0,2806,CLI1_DIV8_ETI338,
00.html>
Some of these units are even available with heating coils/heat pump
options, and so could provide an entire climate control solution for an
EV in an easy to use package.
Cheers,
Roger.
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--- Begin Message ---
Welcome to the list!
On Jul 29, 2006, at 9:02 PM, Paul Francis wrote:
A conversion may be impractical for this northern Pennsylvania climate
area
Why is that? Too cold?
That's not a problem if you design your EV appropriately. Insulate
your battery boxes, maybe use battery heaters, and put in a good cabin
heater, and an EV will work BETTER than a gas car. No starting
problems, instant heat, smooth steady torque at low speeds, great
traction in snow and ice. Ask Roland about running his EV in Montana,
or Lee about running his in Minnesota. (Plus, you might have plugins
for block heaters available in your parking lot, which is great for
free battery charging.)
Too wet? Also not a problem, unless you're driving through several
feet of water, which will kill a gas car too. Just keep your
electronic components out of the spray. (I'm using waterproof plastic
electrical boxes.) The motor won't mind the occasional spray of water.
Too hot? Lead-acid batteries like it warm. Your AC system can be run
by an electric motor. You can even put up solar PV panels on your
house and charge your car for free!
Too windy? EVs are heavier and much harder to tip over.
Rain of frogs? EVs have better traction and will drive through
squished frogs just like through snow. You might need to beef up the
12v system to give the windshield wipers more power.
I just can't seem to think of a climate that's hostile to EVs.
Physical landscapes can be a problem - lots of hills, or long distances
between your house and your destination, or rough roads requiring 4wd.
But these can be designed around, too, if you have the cash.
--
Doug Weathers
Las Cruces, NM, USA
<http://learn-something.blogsite.org/>
--- End Message ---
--- Begin Message ---
Mike Phillips wrote:
The consensus on this list seems to be that DC is better for
performance.
That's because it's a DC list :)
Is there an AC list?
Steve
--- End Message ---
--- Begin Message ---
Steve Condie wrote:
> But lately I've noticed that one of my batteries -
> #13, the extreme + end one - has been running off and
> leaving the rest behind once I get into Z-reg range.. It
> quickly spiked above 15.3 volts while the rest were just at
> the 13.9 - 14.2 volt range.
> I'm sure there's an explanation for this, but I don't
> remember seeing it here. Anyone want to help me understand this?
It kind of depends upon what you mean by getting into "Z-reg range".
>From what you've described, I'm assuming that this means the pack has
reached the desired voltage level and you are now holding the voltage
constant while the current tapers off. It is perfectly normal during
this phase of the charge that the voltage divides unequally across the
modules in the string, such that some are below the pack average and
others are above it. Part of the unequal division may be due to
differnences in the internal impedance of the batteries (consider the
pack as a big voltage divider formed by the series connection of
resistors corresponding to the internal impedances of each module).
Just to complicate matters, the internal resistance of the modules
varies with state of charge, temperature, etc., and often a module will
"hog" voltage early in the constant voltage phase, but will then drop in
voltage later in the phase as some other module rises in voltage.
While this is normal, it is also (in my opinion) where the real risk of
abusing a VRLA lies. If the module voltage gets too high, it may be
unable to recombine the internal gasses rapidly/efficiently enough to
avoid venting even if the pack current is modest, so one must somehow
limit the voltage, or limit the amount of time the module sees high
voltage. What you might consider trying is wiring 2 or more Z-regs
across this module to provide more current bypass capability. This
might avoid the need to readjust the charger to keep the module voltage
within safe bounds.
One thing to be aware of is that the VRLA module voltages are a poor
indicator of state-of-charge near the end of charge. As the modules
near full charge, their voltages are greatly affected by differences in
such things as recombination efficiency. I think this is one of the
possible pitfalls of any scheme that seeks to actively clamp the module
voltages to some arbitrary level, or to pack average, etc. The real
metric to rely on is the module resting voltages some hours after
competion of charge; how similar these voltages are indicates how well
balanced the pack is.
Cheers,
Roger.
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