EV Digest 6335
Topics covered in this issue include:
1) RE: Phoenix motors/UQM Drive
by "Dale Ulan" <[EMAIL PROTECTED]>
2) Re: Battery Monitor Design
by "Rush" <[EMAIL PROTECTED]>
3) Re: OT Copper, was: EEstor
by "Peter VanDerWal" <[EMAIL PROTECTED]>
4) Re: EV Drag racing this year
by "Rich Rudman" <[EMAIL PROTECTED]>
5) Re: Battery Monitor Design
by "Mike Harvey" <[EMAIL PROTECTED]>
6) Re: Using Vortex Tubes for air conditioning/heating
by "Peter VanDerWal" <[EMAIL PROTECTED]>
7) Re: Battery Monitor Design
by Tim Wong <[EMAIL PROTECTED]>
8) Testing the pack
by Don Cameron <[EMAIL PROTECTED]>
9) Re: 120 mph Thrill
by [EMAIL PROTECTED]
10) Re: 120 mph Thrill
by [EMAIL PROTECTED]
11) Re: Lower price (and available) configurations
by Lee Hart <[EMAIL PROTECTED]>
12) Re: super skinny/hard tires .. thin tyres in the 69 psi
by Danny Miller <[EMAIL PROTECTED]>
13) Re: 120 mph Thrill
by [EMAIL PROTECTED]
14) Re: super skinny/hard tires .. thin tyres in the 69 psi
by "Peter VanDerWal" <[EMAIL PROTECTED]>
15) RE: Series/Parallel question....
by Tony Hwang <[EMAIL PROTECTED]>
16) Re: Cutout Question
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Battery Monitor Design
by Lee Hart <[EMAIL PROTECTED]>
18) Re: Testing the pack
by Lee Hart <[EMAIL PROTECTED]>
19) Re: Battery Monitor Design
by "Evan Tuer" <[EMAIL PROTECTED]>
20) Re: OT nitrogen was Re: super skinny/hard tires .. thin tyres in the 69
psi
by "Rush" <[EMAIL PROTECTED]>
21) Re: Battery Monitor Design
by Tim Wong <[EMAIL PROTECTED]>
22) Re: Battery Monitor Design
by Danny Miller <[EMAIL PROTECTED]>
23) Businesses in Colorado
by "Christie Cooksey" <[EMAIL PROTECTED]>
24) FW: Ford Shows a Hybrid Car with 2 Modes: Electric or Electric
by "Jorg Brown" <[EMAIL PROTECTED]>
25) RE: Lower price (and available) configurations
by "Roger Stockton" <[EMAIL PROTECTED]>
26) Call for Help
by Mike <[EMAIL PROTECTED]>
27) Re: Testing the pack
by "Rich Rudman" <[EMAIL PROTECTED]>
28) Re: OT Copper, was: EEstor
by Frank John <[EMAIL PROTECTED]>
--- Begin Message ---
On topic of powerful induction traction motors, there dont seem to be
many alternatives around.
AC Propulsion, Siemens (from MetricMind) come to mind too. Another option
(but you need to be involved in this) is to get a (good) motor rewinding
shop do one up for you. For the Motor Control Electronics Handbook (Richard
Valentine / Motorola), they took a 20HP motor and rewound it down to 30 or
40 volts or so, then proceeded to use it at something like 100kW. It was a
heavy motor to start with, though - maybe 200 or 300kg.
I've used the UQM motors on a hybrid-electric I worked on in university -
very nice units. A bit pricey, though from what I remembered, less pricey
than the AC Propulsion system. We were using one of the forerunners to the
SR-218 (I can't remember the model though) without phase advance. It worked
really well.
-Dale
--- End Message ---
--- Begin Message ---
Really Great Tim,
I think the 'open sourcing' that you have done is great.
Rush
Tucson AZ
www.ironandwood.org
www.Airphibian.com
----- Original Message -----
From: "Tim Wong" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, January 22, 2007 11:49 PM
Subject: Battery Monitor Design
>I have designed and built a battery monitor with LCD display for my Soleq
>EVcort (1993 ford escort converted by Soleq) - please take a look at the
>design, including schematics, pictures, and board layout at this link:
>
> http://home.earthlink.net/~evtkw/
>
> I would love to hear feedback on the system! See any major flaws or
> problems? Like anything? What do you think?
>
> Tim Wong
> 1993 Soleq EVcort
>
>
--- End Message ---
--- Begin Message ---
>
>> still many homes have only 4 breakers, though
>> newer homes are often built with 6 or 7.
>
> Many newer US homes have 40 or more (using subpanels). Twenty, 24, or 30
> was typical several years ago. Four and six fuses with 60 amp services
> were last fitted probably 50-75 years ago in US homes.
Hmm, I own four houses. The oldest is about 40 years old and the newest
is 12. (Bear with me for a moment and I'll bring this back to EVs.)
The main breaker panel in the old house has 4 110V circuit breakers, zero
220V. One 15 amp breaker handles the outlets and lights in the original
bedrooms, bathroom, hallway, 1/2 the living room and 1/2 the kitchen
!!??!!
I guess, back in the '60s, they just didn't have much stuff to plug in.
As I recall, only rich people had more than one TV back then and many
people didn't have any.
I'm pretty sure that originally the house only had 3 breakers (or fuses?)
since one of them is only used by the washing machine and the house was
remodeled to handle a washing machine.
The new house has a large panel that is full...16 breakers. Ok 4 of those
are 220V breakers and take up two slots. But, the panel could only hold a
max of 20 breakers.
I was going to say that with 40 breakers the hous emust be huge, but I
just checked google. Turns out my new house, which I thought was quite
large at 1400 sqf, is actually quite small.
The average American home is 2,349 sqf, the average American family has
slightly over 3 people (those 0.14 kids are hard to keep track of).
Actually the average household size is only 2.59.
That means over 900 sqf per person. I guess those commercials of the
parrents text messaging their kids while both are at home isn't so much of
a joke.
Americans are nuts.
Anyway two points about EVs:
Newer houses obviously have no problem with charging EVs. Even a high
power charger doesn't take much more juice than a sauna or dryer. But
older houses will probably need to be upgraded. Contrary to what some
folks think, there are STILL a lot of US houses out there with very
small service panels.
Second point, Americans are gready (relatively speaking) and not very
conservative (as a whole). I don't believe that we can appeal to the
majority of Americans by building small EVs, or by convincing them that
EVs will save money or the enviroment.
Obviously there will be niche markets for these types of vehicles, but
I don't think the market will support very many of them. To appeal to
large numbers, EVs need to be "New and Improved!" They'll need to be
sexy, they'll need to be fast, to have some zing. Something to appeal
to our rampant consumerism, our bigger and better lifestyle.
--
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 ---
keep in mind that Portland was snowed in last week. And is about 55 Deg
today, We don't do much EV racing when the weather can be this extreme.
I am sure we will have more than a few Wayland nights at Portland.
Heck I am cahrging Goldie right now for the frist time in about 3 months..
so We will be doing some racing, it's just too far off to have any dates in
stone yet.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Mark Fowler" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, January 23, 2007 5:24 AM
Subject: EV Drag racing this year
> (resend - original hasn't appeared after a day)
>
> G'day all,
>
> As I mentioned earlier, I've relocated to Edmonton, Canada for this
> year.
>
> One of the things I want to do while on this side of the planet is to
> see some electric drag racing.
>
> So, what are the plans for EV events at Portland this summer?
> Nothing on the Nedra site yet. Any Wayland stuff going on?
>
> Mark
>
--- End Message ---
--- Begin Message ---
Hey Tim,
Good stuff. Exactly what I envisioned for my Cabby. Great work. Thanks for
sharing. Can I order one:)?
Regards, Mike
----- Original Message -----
From: "Rush" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, January 23, 2007 11:43 AM
Subject: Re: Battery Monitor Design
Really Great Tim,
I think the 'open sourcing' that you have done is great.
Rush
Tucson AZ
www.ironandwood.org
www.Airphibian.com
----- Original Message -----
From: "Tim Wong" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, January 22, 2007 11:49 PM
Subject: Battery Monitor Design
I have designed and built a battery monitor with LCD display for my Soleq
EVcort (1993 ford escort converted by Soleq) - please take a look at the
design, including schematics, pictures, and board layout at this link:
http://home.earthlink.net/~evtkw/
I would love to hear feedback on the system! See any major flaws or
problems? Like anything? What do you think?
Tim Wong
1993 Soleq EVcort
--- End Message ---
--- Begin Message ---
Hmm, an interesting though. Given that they aren't efficient, can they at
least be light weight?
For example, if we had an onboard tank of compressed air (refilled while
charging) and a vortex tube, how large would the tank need to be to store
enough air for cooling the vehicle for say 20 minutes?
Assume we use a simple solar powered fan to keep the vehicle from getting
to hot while parked.
Anybody with experience using these care to comment?
> They are simple, but very inefficient.
> http://www.visi.com/~darus/hilsch/
> http://en.wikipedia.org/wiki/Vortex_tube
>
> Bill Dube'
>
> At 09:22 PM 1/22/2007, you wrote:
>
>>Hello:
>>
>>My apologies if this is stupid or if it has been discussed before.
>>
>>While surfing around, I stumbled over some cooling technologies, that
>>basically uses compressed air. See
>>http://www.exair.com/vortextube/vt_page.htm
>>
>>Now .. I don't have any data, but shouldn't a moving vehicle produce
>>quite some amount of air flow/air pressure that could be used for cooling
>>or heating through a vortex tube?
>>
>>Just an idea here ..
>>
>>Michaela
>
>
--
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 ---
Peter -
Thanks for the input! This is exactly the kind of stuff I wanted to hear.
Nice catch on the RC filter - I had to put one on after the system was
completed to reduce the noise while charging, and i guess I didn't add it to
the schematic... What values would you recommend? I think I added a .1uF cap
between the resistors and the ADC, but can't find what I did!! As i don't have
a lot of experience in analog design, do you have a recommendation sense of
what to add and where? It may be better than what I did...
You are right about the voltage divider - I thought I should getting an ADC
with a 10V input range after building it, which would be much cleaner,
accurate, and not much more expensive, as I used .01% high precision resistors.
The INA148 looks great - a bit more expensive, but looks nice...
Thanks for the input,
Tim
-----Original Message-----
>From: Peter Gabrielsson <[EMAIL PROTECTED]>
>Sent: Jan 23, 2007 9:17 AM
>To: [email protected]
>Subject: Re: Battery Monitor Design
>
>Just nitpicking here, you have a good design but you can significantly
>improve accuracy by getting rid of the 10k/6.04k divider just after
>the lt1990 in the sense box. You'll need to replace the AD converter
>with a higher input voltage converter if you do this.
>
>You also don't have any filtering on the inputs so I'd put an RC
>filter where the divider currently resides. A small improvement in
>linearity can also be achieved by replacing the LT1990 with an INA148,
>though for a lead acid system the LT1990 is probably good enough.
>
>That said, very nice design and thank you for sharing it.
>-Peter
>
>
>--
>www.electric-lemon.com
>
--- End Message ---
--- Begin Message ---
Hi all,
You will have to forgive me for asking a basic question. I have searched
around, but have not really got a clear understanding.
Every couple of months I check my pack to see if any batteries are low.
Here is what I do:
I charge my pack
Wait 24 hours
Measure each battery voltage
Supplemental charge the low ones.
I get the feeling, after readying a few posts about dead packs, that this
procedure is wrong. Can anyone please correct me?
thanks
Don
Don Cameron, Victoria, BC, Canada
---------------------------------------------------
See the New Beetle EV project www.cameronsoftware.com/ev
Check the EVDL Archives: http://autos.groups.yahoo.com/group/ev-list-archive
Check out the EV FAQ: www.evparts.com/faq
Check out the EV Photo Album: www.evalbum.com
--- End Message ---
--- Begin Message ---
In a message dated 1/23/2007 9:34:58 AM Pacific Standard Time,
[EMAIL PROTECTED] writes:
> ubj: Re: 120 mph Thrill
> Date:1/23/2007 9:34:58 AM Pacific Standard Time
> From:[EMAIL PROTECTED]
> Reply-to:[email protected]
> To:[email protected]
> Received from Internet:
>
>
>
> Great, Good for you Mario!
>
> Dennis - are you going to be at Firebird anytime soon? It is much closer to
> Tucson and some of our TEVA2 Club members would love to see the CE.
>
> Rush
> Tucson AZ
> www.ironandwood.org
> www.Airphibian.com
--- End Message ---
--- Begin Message ---
In a message dated 1/23/2007 9:34:58 AM Pacific Standard Time,
[EMAIL PROTECTED] writes:
> ubj: Re: 120 mph Thrill
> Date:1/23/2007 9:34:58 AM Pacific Standard Time
> From:[EMAIL PROTECTED]
> Reply-to:[email protected]
> To:[email protected]
> Received from Internet:
>
>
>
> Great, Good for you Mario!
>
> Dennis - are you going to be at Firebird anytime soon? It is much closer to
> Tucson and some of our TEVA2 Club members would love to see the CE.
>
> Rush
> Tucson AZ
> www.ironandwood.org
> www.Airphibian.com
II will be racing 3 times this year in Tucson.I will post the dates soon.
Dennis Berube
--- End Message ---
--- Begin Message ---
John G. Lussmyer wrote:
I was doing my calcs using L91-4003's, which are 6.7" motors.
What is the advantage of an 8" (or 9") with a Curtis controller?
A bigger motor will be slightly more efficient, will be able to run at a
higher continuous horsepower, and can deliver a higher peak horsepower.
The latter may not matter with a Curtis controller, as it will limit
power before the motor does.
As a way around the Lead Sled acceleration.
Say you used the Dual Curtis w/6.7" motors.
You then had 2 more 6.7" motors that have a simple Contactor control.
Clever! Yes, you could do that. With careful design, the Curtis
controller could provide smooth speed control between the steps of the
contactor controllers.
--
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 ---
I looked it up and saw very different numbers:
O2 26.2 L/mol
N2 25.5 L/mol
13 cc/mol vs 17 cc/mol is a pretty wide spread- this runs contrary to
the accepted principle that gases outside of temp or pressure extremes
all have very similar molar volumes.
The claim that "nitrogen is 5x bigger than oxygen" is clearly false, try
2.74%. Actually molar volume is based on the repulsion between
molecules, rather than the size of a single molecule. The size of a
molecule is somewhat complicated to state, the outer electron shell
would be a much more sensible measurement than the nucleus, but even
that is actually a realm of probability and all. Probably shouldn't
have to learn quantum physics to figure out what type of air to put in a
tire.
Danny
Cor van de Water wrote:
Bzzzzt, wrong answer.
See periodic table of elements:
http://www.webelements.com/
N is element 7, O is element 8.
The molar volume (consisting of a fixed nr of atoms)
of Nitrogen is 13 cube cm, while Oxygen needs 17 ccm,
so Oxygen is larger than N, in gas form that will be
O2 and N2.
--- End Message ---
--- Begin Message ---
In a message dated 1/23/2007 12:29:32 PM Pacific Standard Time,
[EMAIL PROTECTED] writes:
> Subj: Re: 120 mph Thrill
> Date:1/23/2007 12:29:32 PM Pacific Standard Time
> From:[EMAIL PROTECTED]
> Reply-to:[email protected]
> To:[email protected]
> Received from Internet:
>
>
>
> In a message dated 1/23/2007 9:34:58 AM Pacific Standard Time,
> [EMAIL PROTECTED] writes:
> >ubj: Re: 120 mph Thrill
> >Date:1/23/2007 9:34:58 AM Pacific Standard Time
> >From:[EMAIL PROTECTED]
> >Reply-to:[email protected]
> >To:[email protected]
> >Received from Internet:
> >
> >
> >
> >Great, Good for you Mario!
> >
> >Dennis - are you going to be at Firebird anytime soon? It is much closer to
>
> >Tucson and some of our TEVA2 Club members would love to see the CE.
> >
> >Rush
> >Tucson AZ
> >www.ironandwood.org
> >www.Airphibian.com
I I will be racing in Tucson 3 times this year I will let all know the dates
soon.Dennis
--- End Message ---
--- Begin Message ---
I looked into this a bit and apparently they are using membrane filters to
separate the nitrogen.
With a filter what matters, the actual size of the molecule or the molar
volume?
I'm just curious about this nitrogen separation process, but I can't see
any EV application.
> I looked it up and saw very different numbers:
> O2 26.2 L/mol
> N2 25.5 L/mol
>
> 13 cc/mol vs 17 cc/mol is a pretty wide spread- this runs contrary to
> the accepted principle that gases outside of temp or pressure extremes
> all have very similar molar volumes.
>
> The claim that "nitrogen is 5x bigger than oxygen" is clearly false, try
> 2.74%. Actually molar volume is based on the repulsion between
> molecules, rather than the size of a single molecule. The size of a
> molecule is somewhat complicated to state, the outer electron shell
> would be a much more sensible measurement than the nucleus, but even
> that is actually a realm of probability and all. Probably shouldn't
> have to learn quantum physics to figure out what type of air to put in a
> tire.
>
> Danny
>
> Cor van de Water wrote:
>
>>Bzzzzt, wrong answer.
>>
>>See periodic table of elements:
>>http://www.webelements.com/
>>N is element 7, O is element 8.
>>The molar volume (consisting of a fixed nr of atoms)
>>of Nitrogen is 13 cube cm, while Oxygen needs 17 ccm,
>>so Oxygen is larger than N, in gas form that will be
>>O2 and N2.
>>
>
>
--
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 ---
Hi Bill,
Man, the killa cycle looks awesome, I wish I had that pack. :)
Anyways, another thing I wanted to point out, at least it seems with 18650
Lithium Ion cells, they will "self balance" to a certain degree if seriously
out of balance in parallel. I'm not sure if this helps or not, since they may
need to be seriouly out of balance for the more charged cells to charge the
weaker cells?
- Tony
Bill Dube <[EMAIL PROTECTED]> wrote: A lot of mis-information in this thread.
Let's get on the right track:
Lead-acid batteries of the same model and brand parallel very
nicely. (No need for contactor between them.)
You want to "buddy up" the batteries instead of running two
separate series strings. It is best to parallel batteries at the
lowest possible voltage level. This is standard practice.
There are a few reasons for this. First, the pack will last much
longer. Each series string is limited in its capacity by its weakest
battery. Thus, your capacity will be fixed by the single weakest
battery in each string. If you buddy up the batteries, the weakest
battery is very unlikely to be the buddy of the other weakest
battery. The stronger buddy helps the weaker buddy. It takes a lot of
weak batteries to seriously reduce your capacity.
Think of the effect of two (or three) 1/2 capacity batteries. If
they are buddied up with full capacity batteries, your pack capacity
will be reduced by 25%. If they are in each series string, your pack
capacity will be reduced by 50%.
In separate series strings, the weak batteries are "tortured" by
the full capacity batteries that surround them. They are cycled to
near (or beyond) their capacity each time. If they have a healthier
buddy, the weak battery uses it as a crutch and it ages much more
slowly because its cycle depth is greatly reduced.
The reliability of the pack goes up. A couple of corroded
connections are not likely to disable the car.
On the KillaCycle, we have 880 cells. We run 8 in parallel and 110 in
series. We parallel at the cell level.
Here is a picture of the pack:
http://www.killacycle.com/photos/a123/packinside.JPG
(Click on the picture for an even BIGGER picture.)
Bill Dube'
--- End Message ---
--- Begin Message ---
Bill Dennis wrote:
The Curtis 1231C controller wiring diagrams have the pot box switch
controlling both the KSI relay and main contactor coils. What ensures
that the KSI open before the main contactor opens? Is it just that the
contactor's inductor is bigger, so it takes longer to de-energize?
It doesn't actually matter, since when you release the throttle, the pot
itself commands zero current before the switch commands the contactor to
open and KSI to turn off.
--
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 ---
Tim Wong wrote:
I have designed and built a battery monitor with LCD display for my
Soleq EVcort (1993 Ford escort converted by Soleq) - please take a
look at the design, including schematics, pictures, and board layout
at this link: http://home.earthlink.net/~evtkw/
Wow! It looks very good. I don't see how you are isolating your pack
from the microcomputer electronics, though.
--
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 ---
Don Cameron wrote:
Every couple of months I check my pack to see if any batteries are low.
Here is what I do:
I charge my pack
Wait 24 hours
Measure each battery voltage
Supplemental charge the low ones.
I get the feeling, after readying a few posts about dead packs, that this
procedure is wrong. Can anyone please correct me?
Sounds reasonable to me. Why do you think there is something wrong with it?
--
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 ---
On 1/23/07, Tim Wong <[EMAIL PROTECTED]> wrote:
You are right about the voltage divider - I thought I should getting an ADC
with a 10V input range
after building it, which would be much cleaner, accurate, and not much more
expensive, as I used
.01% high precision resistors.
The INA148 looks great - a bit more expensive, but looks nice...
I used INA148s for my Li-Ion BMS (with 10-bit ADC). It works well.
Regards
Evan
--- End Message ---
--- Begin Message ---
When divers do deep dives in dry suits, they often use argon gas as a dry suit
gas instead of the mix they are breathing. Argon is an inert, light gas with a
low molecular conductivity. Compared to other gases, air included, it is a good
insulating gas. At depth in the ocean, the water is cold and you want as much
insulation as possible as you only have your body as a heat source.
Maybe we should put it our tires to decrease the effects of heat.
See http://www.decompression.org/maiken/Why_Argon.htm for technical explanation.
Rush
Tucson AZ
www.ironandwood.org
www.Airphibian.com
> Probably the same reason as some people go through the
> effort of installing vortex generators - clever marketing
> of a change that has no measurable benefit.
> And it is cool to say you have Nitro in your tires.
> Sounds really hot-rod.
> I value it at about the level of a ricer.
> (Paint it orange and it goes much faster,
> or bolt some cheap sheet metal on the trunk
> for more down-pressure on the non-driven wheels)
--- End Message ---
--- Begin Message ---
Thanks! Here is the LT1990 chip that is between the ADC and the battery:
http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1154,C1009,C1126,P7521
It has a fairly big input impedance... Do you think that is sufficient
isolation? Do you have any suggestions for better isolation? The actual
microprocessor is in a different box, connected with 3 wire serial to the ADC -
do you think that is also vulnerable?
Thanks,
Tim
-----Original Message-----
>From: Lee Hart <[EMAIL PROTECTED]>
>Sent: Jan 23, 2007 1:08 PM
>To: [email protected]
>Subject: Re: Battery Monitor Design
>
>Tim Wong wrote:
>> I have designed and built a battery monitor with LCD display for my
>> Soleq EVcort (1993 Ford escort converted by Soleq) - please take a
>> look at the design, including schematics, pictures, and board layout
>> at this link: http://home.earthlink.net/~evtkw/
>
>Wow! It looks very good. I don't see how you are isolating your pack
>from the microcomputer electronics, though.
>
>--
>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 ---
Nice, all the way. A few notes.
The "+5v transorb" should not be there. Without extenuating
circumstances such as a major inductive load, there is no reason to put
anything but a cap after a linear regulator. Also due to tolerances in
a transorb/zener and regulator, the transorb can easily turn on and
short out the reg if it is not sized some amount greater than the stated
reg voltage.
How are you getting the +/- 15v on the LT1990's? Is that actually the
+/- 12v? I'm wondering because the ADC's analog ground needs to be the
exact midpoint between the two supplies IIRC how that amp operates.
I agree there is a possible issue with the resistor tolerances on the
dividers. Actually what I would do is use an analog mux switch and a
single voltage divider, then you only need one calibration. I would
personally use a PIC with its 10-bit ADC rather than a special-purpose
deal. It has more versatility for one, and of course you'll be able to
do things like control that analog mux. In fact it would be a good idea
to have the whole sensor on a shared optically isolated bus (like that
EVilBus thing) and a PIC would have no problem driving this.
I strongly argue against BASICStamps. Parallax has done a lot of
marketing saying it's too difficult and expensive to learn to use a PIC
without their stuff. None of this is true, it's just negative hype and
way too many new guys have gotten suckered into working with them.
There are far more free tools and help forums on the net for PIC too!
BASICStamp is just a very badly degraded PIC system and made terribly
expensive and inflexible to boot.
Danny
Tim Wong wrote:
Peter -
Thanks for the input! This is exactly the kind of stuff I wanted to hear.
Nice catch on the RC filter - I had to put one on after the system was
completed to reduce the noise while charging, and i guess I didn't add it to
the schematic... What values would you recommend? I think I added a .1uF cap
between the resistors and the ADC, but can't find what I did!! As i don't have
a lot of experience in analog design, do you have a recommendation sense of
what to add and where? It may be better than what I did...
You are right about the voltage divider - I thought I should getting an ADC
with a 10V input range after building it, which would be much cleaner,
accurate, and not much more expensive, as I used .01% high precision resistors.
The INA148 looks great - a bit more expensive, but looks nice...
Thanks for the input,
Tim
-----Original Message-----
From: Peter Gabrielsson <[EMAIL PROTECTED]>
Sent: Jan 23, 2007 9:17 AM
To: [email protected]
Subject: Re: Battery Monitor Design
Just nitpicking here, you have a good design but you can significantly
improve accuracy by getting rid of the 10k/6.04k divider just after
the lt1990 in the sense box. You'll need to replace the AD converter
with a higher input voltage converter if you do this.
You also don't have any filtering on the inputs so I'd put an RC
filter where the divider currently resides. A small improvement in
linearity can also be achieved by replacing the LT1990 with an INA148,
though for a lead acid system the LT1990 is probably good enough.
That said, very nice design and thank you for sharing it.
-Peter
--
www.electric-lemon.com
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--- Begin Message ---
I live in Australia but am planning a trip to Denver in June...
Are there any EV businesses anywhere in Colorado that I could visit?
Cheers
Christie
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--- Begin Message ---
From
http://www.nytimes.com/2007/01/23/washington/23hybrid.html?_r=1&8dt&emc=dt&oref=slogin
Ford Shows a Hybrid Car With 2 Modes: Electric or ElectricWASHINGTON, Jan.
22 — Move over, gas-electric hybrid. Ford has a new entry, the
electric-electric hybrid.
The vehicle, based on a Ford Edge crossover, runs on electricity from a
battery, charged either from a standard wall socket or from an on-board fuel
cell. It has two highly visible fueling ports, both on the driver's side of
the vehicle. One is a hose coupling for hydrogen gas, and the other is an
electric connection like the one on a leaf blower, ready for a standard
three-prong extension cord.
"I told the design team to make them prominent," said Mujeeb I. Ijaz, the
manager of fuel-cell vehicle engineering at Ford.
Energy specialists say they think the plug-in hybrid could cut oil
dependence by allowing a car to go the first 25 or 30 miles each day on
energy drawn from the power grid, most of which is generated from coal. That
would cover the entire commute of most drivers on most days.
But almost all plug-in hybrid designs have a gasoline engine as a backup, to
provide range. The plug-in Edge is the first to use a fuel cell instead,
according to Ford.
Marrying a fuel cell to a battery allows the fuel cell to run at a constant
rate, which is gentler on the hardware than having it cycle up to its
maximum when the car is accelerating and then down to nothing. And it means
that the fuel cell can be much smaller, because it does not need to be sized
to handle maximum load.
The plug-in hybrid Edge has a 35-kilowatt fuel cell and a 130-kilowatt
electric motor drive.
Mr. Ijaz said that fuel cells were less expensive than they used to be, but
were still near $1,000 for a kilowatt of capacity, about 10 times the price
of a kilowatt from a battery, and 30 times the price of a kilowatt from a
gasoline engine.
The finished product (of which there is exactly one) illustrates the
economics of hydrogen. At $5 a kilo of hydrogen (which is the selling price
at a demonstration fueling station here, but probably far below actual
cost), a dollar's worth will push the Edge about eight miles. But a consumer
who charged the batteries at 10 cents a kilowatt-hour, roughly the national
average retail price, would go 25 miles on a dollar's worth.
(A gasoline vehicle that gets 20 miles a gallon on unleaded regular at $2.25
a gallon would go a little less than 9 miles on a dollar's worth.)
The Edge was built as an experiment, not as a money-saver. Partly financed
by the Energy Department, it cost about $2 million. The assistant secretary
of energy for conservation and renewables, Andrew Karsner, is scheduled to
appear at the Washington Auto Show on Tuesday to discuss the Edge and other
vehicles.
Among its disadvantages is a hydrogen tank that takes up about seven times
as much space as a gasoline tank that would provide the same useable energy.
The Edge has switches that allow the driver to plan a trip and do the last
few miles on battery, with the fuel cell shut down, to maximize use of
electricity from the grid, not from hydrogen. The tailpipe emits only
low-temperature water vapor. On Sunday afternoon, at 32 degrees, as Ford
raced to get photos of the vehicle before the snow started, Mr. Ijaz aptly
described the tailpipe as looking like a dryer vent. In warmer weather the
vapor would not be so visible.
Running in cold weather has another complication; the Edge uses electric
resistance heat, supplemented by waste heat from the fuel-cell stack. The
air-conditioner is also electric. Both cut slightly into range. With fuel
compressed to 5,000 pounds per square inch, range is 200 miles (plus 25
miles on electricity stored from the initial battery charge); Ford, like the
rest of the fuel-cell industry, plans to shift to fuel cells that use
hydrogen stored at 10,000 p.s.i.
In city and highway traffic, the car, like most electrics, has no vibration,
and the tire sounds are prominent because there is no engine noise to mask
them. The sound of a compressor that pumps air through the fuel cell is also
prominent.
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--- Begin Message ---
John G. Lussmyer wrote:
> I was doing my calcs using L91-4003's, which are 6.7" motors.
> What is the advantage of an 8" (or 9") with a Curtis controller?
>
> A bigger motor will be slightly more efficient, will be able
> to run at a higher continuous horsepower, and can deliver a
> higher peak horsepower.
> The latter may not matter with a Curtis controller, as it will
> limit power before the motor does.
I'm not so sure that this would be the case. The L91 is rated 130A
continuous, 150A for 1hr, and 500A peak; a 1221C is rated 400A (2min),
250A (5min), and 150A (1hr). A 1231C is rated 500A (2min), 375A (5min),
and 225A (1hr). It seems that unless one took measures to ensure their
Curtis was poorly cooled, a 1231C is quite capable of abusing a small
motor like this in a heavy vehicle, and even the smaller 1221C might be
able to overheat the motor before iteself heating enough to derate to a
safe level.
> > As a way around the Lead Sled acceleration.
> > Say you used the Dual Curtis w/6.7" motors.
> > You then had 2 more 6.7" motors that have a simple
> > Contactor control.
I've lost the original posts in this thread, so forgive me if I'm
misremembering, but wasn't a stated objective of the thought exercise to
see what could be done for less money than a pair of larger motors and a
Zilla?
Unless I'm misreading what you wrote above (and misremembering from
prior posts), it seems the original suggestion is a pair of L91-4003's,
each fed by its own Curtis, and each Curtis fed by its own 120V string
of 6V GCs.
The L91 goes for $915/ea, and a 1221C for $1025. There's no doubt that
a pair of L91's is cheaper than a pair of 8's ($1364-1390/ea), but you
now seem to suggest two pairs of L91's, which runs you up to nearly
$4000 in motors. A pair of 1221C's is barely competitive with a Z1K LV
at $2050 for the Curtii vs $2025 for the Z1K, and loses on a bang for
the buck measure with 800A (total peak) vs 1000 for the Z1K.
Anecdotal reports from EV truckers in the past have suggested that a
single 8" or 9" is marginal even in an S10/Ranger type vehicle at about
120V of 6V GCs. The concerns, as I recall, were both sluggish
performance and motor overheating on hills or at speed. An 8" weighs
110lbs, while the L91-4003 weighs 85lbs, so a pair of L91's have a bit
more total weight and so might very well address these concerns... If
fitted to a Ranger/S10 conversion. However, your proposal is for a
vehicle close to 2x this, so it might very well require 4 of the smaller
motors to handle the power requirements without overheating.
If you did want to go with the smaller motor approach, I would suggest
seriously considering the X91-4001 motor instead. There are a couple of
reasons. It is very slightly heavier than the L91 (87 vs 85lbs), it has
a tailshaft (which the L91 does not) to facilitate simple end-to-end
coupling of dual motors, and at the ~400A level you'd feed it with the
1221C, it produces more torque per amp than the other ADC models (L96,
8", and 9"!). If you had more amps on tap, the bigger motors really
start to stand out from the little ones, but at the 400A level the X91
looks like the real stump-puller. To top it off, the X91 is even a bit
cheaper than the L91 ($889 vs $915).
I would also suggest that the Z1K HV (72-300V) at $2600 might be the
wisest controller choice. It is slightly more costly than a pair of
1221Cs, but is also more powerful at 1000A vs 800A, and would allow you
to connect your 40 6VGCs in a single 240V string. In reality, the Z1K
could allow significantly better performance than the pair of Curtii
because it supports series-parallel shifting and so could allow up to
the full 1000A through each motor at low speeds, for more than 2x the
low speed torque of the dual Curtis setup. The X91 is rated to 144V,
and feeding the Z1K from 240V would ensure a broader constant torque
band than feeding each from just 120V (of sagging floodeds). Assuming
the X91 has a similar 500A peak rating as the L91, you might just want
to turn the Z1K motor current limit down to 500A, but at least the Z1K
allows you to do this and separately set the battery current limit to a
safe level to protect your flooded pack without compromising low end
torque the way the single setting on a Curtis would. Obviously, the fly
in the ointment here is that you could have a pair of Curtii immediately
but might have a 6 month wait for the Z1K. It is also somewhat of a
questionmark if the 174lbs of motor (2 x X91) would be enough to avoid
overheating in a vehicle this large given that 110-140lb of motor (1 x
8" or 9") is anecdotaly marginal in Ranger/S10-type applications. On
the plus side, the wide input range of the Z1K HV would allow you to
tailor the pack voltage/weight so that you weren't carrying more battery
than you end up needing to make your desired trips, and this could make
life easier on the motors.
Cheers,
Roger.
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--- Begin Message ---
I hang out in the forums at CNCZone.com, a community for folks who
are into building CNC machines. They recently started a new forum
about global warming and it turns out some people still believe it's
all fake. Some sort of plot by the lefties or some such BS. Of
course the topic has turned to EVs and some people are making the
typical quips about running the heater and destroying range and
everyone's favorite, that EVs are slow.
I've done the basic thing like post links to FAQs and stuff but if
someone smarter than me would like to help educate I'd be much
appreciated.
http://www.cnczone.com/forums/forumdisplay.php?f=343
http://www.cnczone.com/forums/showthread.php?t=30772
Mike
--
The Electric Motorcycle Portal
http://www.electricmotorcycles.net/
Electric Motorcycle Listserv
http://www.electricmotorcycles.net/listserv
--- End Message ---
--- Begin Message ---
Hey what I do is run the charger for a couple of days and let the Regs beat
the UNequalness out of the cold tired Lead.
Seams to have worked on Goldie's Orbs.
It's 50 plus here in Seattle..
We were froze up last week. Gee feels like summer.
Maybe I can get some EV miles and that is a improvement over Hybrid miles.
But man! the tunes and the seats and the comfort of the E-scape is a lot
better than a busted bucket seat and loose stearing that makes Goldie just
sooo much fuunn..
The 1200 amps and smoking rubber does make up the difference.
Madman
----- Original Message -----
From: "Don Cameron" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, January 23, 2007 12:00 PM
Subject: Testing the pack
> Hi all,
>
> You will have to forgive me for asking a basic question. I have searched
> around, but have not really got a clear understanding.
>
> Every couple of months I check my pack to see if any batteries are low.
> Here is what I do:
>
> I charge my pack
> Wait 24 hours
> Measure each battery voltage
> Supplemental charge the low ones.
>
> I get the feeling, after readying a few posts about dead packs, that this
> procedure is wrong. Can anyone please correct me?
>
> thanks
> Don
>
>
> Don Cameron, Victoria, BC, Canada
>
>
> ---------------------------------------------------
> See the New Beetle EV project www.cameronsoftware.com/ev
>
> Check the EVDL Archives:
http://autos.groups.yahoo.com/group/ev-list-archive
>
> Check out the EV FAQ: www.evparts.com/faq
>
> Check out the EV Photo Album: www.evalbum.com
>
>
>
>
--- End Message ---
--- Begin Message ---
I think that improved transportation security vis-a-vis American Electrons
versus Imported Oil will appeal to lots of folks.
----- Original Message ----
From: Peter VanDerWal <[EMAIL PROTECTED]>
To: [email protected]
Sent: Tuesday, January 23, 2007 1:31:47 PM
Subject: Re: OT Copper, was: EEstor
"I don't believe that we can appeal to the majority of Americans by building
small EVs, or by convincing them that
EVs will save money or the enviroment. Obviously there will be niche markets
for these types of vehicles, but
I don't think the market will support very many of them. To appeal to large
numbers, EVs need to be "New and Improved!" They'll need to be
sexy, they'll need to be fast, to have some zing. Something to appeal to our
rampant consumerism, our bigger and better lifestyle."
____________________________________________________________________________________
Yahoo! Music Unlimited
Access over 1 million songs.
http://music.yahoo.com/unlimited
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