EV Digest 2622
Topics covered in this issue include:
1) Re: EV PC
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Liability (was Re: Gliders (part 3)
by Lee Hart <[EMAIL PROTECTED]>
3) Re: SVR 14 batteries 4 sale SP17 Marathorn Nicads 4 sale
by "1sclunn" <[EMAIL PROTECTED]>
4) RE: Chinese EV Not As Pictured
by "Walker, Lesley R" <[EMAIL PROTECTED]>
5) RE: BMS cost (was Re: LIN bus link)
by "George Tylinski" <[EMAIL PROTECTED]>
6) Re: Liability (was Re: Gliders (part 3)
by Peter VanDerWal <[EMAIL PROTECTED]>
7) Re: Gliders (part 3)
by Chip Gribben <[EMAIL PROTECTED]>
8) 6 Volt Battery Balancer?
by [EMAIL PROTECTED]
9) Re: Mellow Yellow's finally about to hit the road!
by [EMAIL PROTECTED]
10) RE: Gliders (part 3)
by "Mark Fowler" <[EMAIL PROTECTED]>
11) RE: BMS communication
by "Mark Fowler" <[EMAIL PROTECTED]>
12) Re: EV PC
by [EMAIL PROTECTED]
13) Re: 6 Volt Battery Balancer?
by Lee Hart <[EMAIL PROTECTED]>
14) Re: BMS cost (was Re: LIN bus link)
by Lee Hart <[EMAIL PROTECTED]>
15) RE: BMS communication
by "James Jarrett" <[EMAIL PROTECTED]>
16) RE: 6 Volt Battery Balancer?
by "Chris Tromley" <[EMAIL PROTECTED]>
17) Re: BMS cost (was Re: LIN bus link)
by Lee Hart <[EMAIL PROTECTED]>
18) Re: EV Range/Speed Check
by Lee Hart <[EMAIL PROTECTED]>
19) Re: Mellow Yellow's finally about to hit the road!
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
20) Re: Liability (was Re: Gliders (part 3)
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: EV PC
by Victor Tikhonov <[EMAIL PROTECTED]>
22) Re: SVR 14 batteries 4 sale SP17 Marathorn Nicads 4 sale
by [EMAIL PROTECTED]
23) Re: BMS communication
by Victor Tikhonov <[EMAIL PROTECTED]>
24) Re: BMS cost (was Re: LIN bus link)
by Rich Rudman <[EMAIL PROTECTED]>
--- Begin Message ---
> Lonnie Borntreger wrote:
>> Here is the cool part... Then you wouldn't be driving "the same car
>> for whole life". You could have a truck, minivan, car, or whatever
>> you're in the mood for on any given day.
Victor Tikhonov wrote:
> And pay insurance for as many cars as many body shells you
> have, because they are legally different cars. Not so cool.
No; not if the VIN number was on a part of the car that wasn't changed
when you change body styles!
Many VIN numbers are on the dashboard, along the bottom of the
windshield. A *lot* of the car can be changed before you have to disturb
this area.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
> Consider this example. A while back a kid was riding his new bicycle
> at night with no lights and got hit by a car. Now the manual that
> came with the bike stated that if you are going to ride at night
> you need to add lights to the bicycle. The jury decided that they
> didn't state this "strongly enough" and awarded the kids family 4
> million dollars.
Be careful, folks. A *lot* of these stories are apocryphal (i.e. they
have left out important details, or changed the facts, or just plain
made it all up). Be *very* wary of stories like this that don't have one
single verifiable fact (no names, no dates, no places). They have fallen
to the level of idle gossip.
Things *do* go wrong in the legal system, but not as often as you might
think. And, many errors do get corrected on appeals.
I, for one, will not avoid worthwile actions by hiding under the bed
from the lawyers!
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
svr14 how many ah are these what is the lbs. the sp17 what is the ah on
them also.? lbs?
have been thinking of doing a setup with 13 YT's and 13 of some smaller bat
and having them so they could be seriesed or paralleled to get 156 for
driving or 312v for a short blast of neck snapping power most of the time
the bats with be in parallel .
would probable charge them in parallel . any ideas on this
Steve Clunn
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, February 24, 2003 6:16 PM
Subject: Re: SVR 14 batteries 4 sale SP17 Marathorn Nicads 4 sale
> I have lowered the price on the new svr14 batteries they are now $15ea.10
> minium. I also have 375 SP17 nicad cells.SP is Marathons desc.for
> superpower.They were used to start helicopter turbines.Each cell was ck.an
> meet mfg.specs for ah.discharge.Links and cases included.$2000.00 +
shipping
> Dennis Berube 6023777583
>
>
--- End Message ---
--- Begin Message ---
Rick wrote:
> Not only are you being infringed on, the bottom of the Web
> site home page has other "borrowed" images that would lead
> one to conclude that GM, The EV History On-line Museum and
> Didik Enterprises were also involved with this project.
To me, the segment with the pictures at the bottom of the page
looks more like a sidebar with background information, and I
wouldn't conclusion that you did.
The Electro Automotive car on the other hand, although the
text doesn't actually claim that the picture belongs to the
project, it strongly implies it by the placement of the picture.
> I smell something brewing. Not sure if it's a fat copyright case,
> liable, or potential scam game to try to bilk investment monies.
<grin> No offence, but you don't seem to know a lot about the
world outside North America. China is not a signatory to the Berne
Convention, which means you can't enforce copyright law there.
Which is why you can buy $5 Rolex watches on the streets (I have
one of those). Your libel laws do not apply in China either.
I think the most likely explanation for the picture being there
is that some editor asked if there was a picture to go with the
story, somebody else said "yes", couldn't get one, and then had
to go and find one or they would lose face. In China it just
wouldn't be done to say "sorry boss, I couldn't find a picture".
It's often very difficult for westerners to get a straight answer
from people in China, because if they think that the answer you
want is "yes" they will say "yes" regardless, or they won't
answer at all. That's why Shari hasn't had a reply to her email,
and probably never will.
I think the only way they would take the picture down would be
if they could do it without losing face, for instance if someone
gave them a picture of the real car.
The other thing to bear in mind is, maybe the project team are
copying the styling of that car (I wouldn't blame them if they
were), and therefore see it as perfectly reasonable to provide
that picture to show what they're doing.
--
Lesley Walker
LRW_at_clear.net.nz
[EMAIL PROTECTED] until 17 March
"[Hybrid electric vehicles] are self-sustaining,
as long as you keep putting gas in the tank."
--- James R. Healey, USA Today
--- End Message ---
--- Begin Message ---
In my conversation with John Olsen, when he worked for Optima, the best
spot for a sensor on an Optima battery in his opinion was in one of the
inner pockets, about 2/3 of the way up. I don't recall what his basis
was, if he even told me.
If you have a running vehicle, you could put 5 or 6 thermocouples on it
and read them near the end of charging. Some variation would be expected
depending on the heat loss field around a battery in a particular
location, and the ambient temperature (which would dictate the rate of
heat loss).
The accuracy would be based on the temperature compensation error vs. Ah
capacity (or state of charge?), and how much you allow that to vary from
one battery to the next. Someone closer to the topic will have to supply
numeric examples. I'd be surprised if Lee Hart hasn't already spelled
this out in the archives somewhere.
The sensor cost has to include how it mounts - is it measuring the air
temp or the battery temp? Luckily the temperature rate of change is
slow, so it need not be a small thermal mass, and the thermal resistance
between the sensor and the "load" isn't a killer. Also, if you have a
battery heating or temp control system, the temp range relevant to
accuracy is fairly narrow. It would be nice if there was a way to check
it's accuracy if its output is suspect (compare to some standard while
it's mounted).
One idea is to buy many thermistors and select the most accurate (or
best matched) ones by testing at some typical temperature (expected near
the end of charging).
If the accuracy is bad you end up with a battery unbalancing system...
- GT
> -----Original Message-----
> From: Chris Brune [mailto:[EMAIL PROTECTED]
> Sent: Wednesday, February 26, 2003 7:41 PM
> To: [EMAIL PROTECTED]
> Subject: Re: BMS cost (was Re: LIN bus link)
>
>
>
> From: "Rich Rudman"
> > Mk3s will use 2 more lines for RXD and TXD data flow. And then the
> > Sky's the limit. I hope to also support a Analog Reg as well as the
> > Digi reg on the same bus. So you won't have to have all
> Digi regs. You
> > should be able to mix and match. For say, a Digi reg in
> each battery
> > box, for local Temps.
> >
> > I say you need Battery temp and voltage, and which battery you are
> > measuring. The dissapation, will take care of itself.THE
> rest is fluff
> > Feature creap will then drag you into measuring everything, and
> > sending it down that expensive data buss you have.
> >
> > Evercells NEED temp data badly in summer conditions. I expect that
> > there will be dozzens of new Evercell systems once they get here in
> > volume. This is going to happen and very soon.
> >
> > We will have Digi Regs by June 03 one way or another.
>
> Does anyone have any ideas on what the best way to monitor
> battery temperature is? Where should the sensor go? What
> kind of accuracy is really needed?
>
> Keeping in mind that the sensor needs to be pretty cheap if
> its going to go on every battery.
>
> If the sensor is near a dissipative regulator that isn't
> going to be good.
>
> LIN based opto-isolated battery voltage monitor almost ready
> for PCB layout... Does anyone think a Palm could be made to
> talk LIN? Maybe a RS-232 to LIN converter?
>
> Chris Brune
>
--- End Message ---
--- Begin Message ---
On Wed, 2003-02-26 at 23:44, Lee Hart wrote:
> > Consider this example. A while back a kid was riding his new bicycle
> > at night with no lights and got hit by a car. Now the manual that
> > came with the bike stated that if you are going to ride at night
> > you need to add lights to the bicycle. The jury decided that they
> > didn't state this "strongly enough" and awarded the kids family 4
> > million dollars.
>
> Be careful, folks. A *lot* of these stories are apocryphal (i.e. they
> have left out important details, or changed the facts, or just plain
> made it all up). Be *very* wary of stories like this that don't have one
> single verifiable fact (no names, no dates, no places). They have fallen
> to the level of idle gossip.
>
In this case it was from a magazine article in "Bicycling" talking about
how out of hand law suits were getting with bike manufacturers. The
other law suit they mention was the guy giving his wife a ride on the
handlebars when she fell off and he ran over her, they sued the bike
store and manufacturer for not having a sticker on the bike saying that
this was unsafe.
This was about seven years ago so I don't have the article anymore, I
just remember the main points. The article did mention the names of the
cities and manufacturers but not the individuals.
The last bike I bought came with a large manual that had a BIG yellow
triangle on every other page with an exclamation mark and then a
sentence under it that said something like "Caution, this bike is only
designed for one person at a time", "Caution, do not try to grab the
wheels when they are moving", etc.
--- End Message ---
--- Begin Message ---
Back in 1994 I was planning to build EVs from Ford gliders. A fellow who was
an engineer at Goddard Space Flight Center took an interest in my Ford
Escort EV and wanted to go into partnership building some. He worked at
Goddard on battery projects for satellites.
He actually wrote up a business plan and legal agreement and presented it to
me at my home. At the time I was thinking, "I'm just a backyard hobbyist.
Why would anyone want to go in business with me to build EVs?" But this guy
was serious. He had some big plans which seemed a bit ambitious to me.
So I did some research on gliders and received information from Ford on how
to sign on with their glider program. I still have the letter and glider
information from 1994.
Ford called their glider program the Qualified Vehicle Modifier (QVM)
Program. Its based on the same program they use for manufacturers of
Ambulances.
In the agreement, Ford established the guidelines for engineering, testing
and manufacturing, quality and service. Converters or QVMs must go through a
review process to ensure the guidelines are met and in return the converters
have limited access to Ford's engineering data and service support.
Also each converter was expected to commit to a reasonable volume of
gliders. The glider program was limited to two vehicle lines. Qualified
converters were required to demonstrate financial responsibility for
potential liability resulting from the conversions.
For vehicles sold in CA Ford, would provide financial consideration to the
converter in exchange for the ZEV credit generated by the converted vehicle.
I never did follow through with this plan and I showed the legal agreement
from the fellow at Goddard, to a lawyer friend and he didn't think the
partnership would be a good idea or last so I dropped it.
But like everyone else I wish I had the resources and money to follow
through on building a dream EV for the masses.
On 2/25/03 10:59 PM, "Electric Vehicle Discussion List"
<[EMAIL PROTECTED]> wrote:
> From: Sam Harper <[EMAIL PROTECTED]>
> Date: Tue, 25 Feb 2003 21:57:50 -0500
> To: [EMAIL PROTECTED]
> Subject: Gliders (part 3)
>
> As I continue my train of thought, I've begun to agree that Li-Ions
> will not do for a first commercial EV. I have begun talking with the
> guys over at Marathon in reference to their NiCads, and I'll give SAFT
> a call tomorrow (though I know I'll hear "expensive" and "quantity). I
> still believe that an AC drive system will perform better, but this
> goes back to the personal opinion. I've been looking around at
> kit-cars and can't find one that appeases me, although I like the idea
> of doing a batch of EV shelby cobra 427s :) Now on to the topic at
> hand, gliders. What are the chances that a modern day car manufacturer
> will sell rolling gliders? I can understand why little old Geo sold
> units to Solectria, but since the consolidation, I cant see a Honda or
> a GM releasing cars when they know they're going to be sold as EVs and
> directly compete. I can really only see buying a batch of used
> vehicles (fleet? wholesale with a dealers license?) and selling off
> the ICE components. An interesting idea might be to buy something like
> an Acura RSX Type-S (Wholesale used around between $14k-$16k) and sell
> the Type-S engines to the import tuner crowd. They go for about $6k
> right now (I have a Civic, I wanted to do a swap for the longest time).
> This way you can get a sporty rolling-chassis for just under $10k that
> would be ready for conversion. As for new, what can we do? Until
> established I can't see going off and pulling a Tango or a Sparrow,
> because the R&D cost is so phenomenal. Comments? Recommendations?
>
> -Sam Harper
--- End Message ---
--- Begin Message ---
I'm looking into building a battery balancer based on Lee's Battery Balancer. I can't
find something to replace the BatMod for a 6 volt battery with a 72 volt input. I'm
looking for something around 8 amps. Any suggestions?
thanks,
Steve
--- End Message ---
--- Begin Message ---
In a message dated 26/02/03 21:19:10 GMT Standard Time,
[EMAIL PROTECTED] writes:
> So now, the registration document is winging
> its way to the DVLA for them to record it as
> an electric, then I can get my tax disc, MOT
> and insurance!
Woops, wrong way round.
The easy way to do this was Insurance first, MOT second (make sure they get
the fuel type correct). Then take proof of insurance, MOT, and registration
document (with changes to fuel and tax class written in) to your nearest DVLA
office. In my case they just took my registration document to be sent to
Swansea (saving me the cost of a stamp) and issued a tax disc on the spot.
Paul Compton
BVS technical officer www.bvs.org.uk
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
Hi all,
Kit cars have the advantage that you only buy what you need.
You don't have to pay for an ICE, fuel tank, radiator, etc that you're not going to
use.
Even better, you don't have to remove them.
Since you are building the car from scratch, it should be fairly easy to get in and
weld/attach battery boxes and mounts for the motor and controllers etc.
My plan is to use a Clubman Roadster from PRB Australia
(http://www.prbaustralia.com.au).
It meets the Australian Design Rules, and has a roll bar (which the S1 doesn't seem to
have), and has a more classic look than the S1.
Mark
-----Original Message-----
From: Sam Harper [mailto:[EMAIL PROTECTED]
Sent: Thursday, 27 February 2003 4:21 AM
To: Humphrey, Timothy; [EMAIL PROTECTED]
Subject: Re: Gliders (part 3)
I like it, and came across it and the MK III, but it just doesnt look
safe. What happens if you roll? What happens if you get rear ended?
-Sam Harper
On Wednesday, February 26, 2003, at 12:13 PM, Humphrey, Timothy wrote:
> I know it's a matter of personal taste, but my dream ev kit would be
> something like this;
>
> http://www.superformance.com/s1.asp
>
> it's not the most aerodynamic, but I'm not going for max range either.
>
>
> Stay Charged!
>
> Hump
>
>
>
>
>> -----Original Message-----
>> From: Sam Harper [mailto:[EMAIL PROTECTED]
>> Sent: Tuesday, February 25, 2003 9:58 PM
>> To: [EMAIL PROTECTED]
>> Subject: Gliders (part 3)
>>
>>
>> As I continue my train of thought, I've begun to agree that Li-Ions
>> will not do for a first commercial EV. I have begun talking with the
>> guys over at Marathon in reference to their NiCads, and I'll
>> give SAFT
>> a call tomorrow (though I know I'll hear "expensive" and
>> "quantity). I
>> still believe that an AC drive system will perform better, but this
>> goes back to the personal opinion. I've been looking around at
>> kit-cars and can't find one that appeases me, although I like
>> the idea
>> of doing a batch of EV shelby cobra 427s :) Now on to the topic at
>> hand, gliders. What are the chances that a modern day car
>> manufacturer
>> will sell rolling gliders? I can understand why little old Geo sold
>> units to Solectria, but since the consolidation, I cant see a
>> Honda or
>> a GM releasing cars when they know they're going to be sold
>> as EVs and
>> directly compete. I can really only see buying a batch of used
>> vehicles (fleet? wholesale with a dealers license?) and selling off
>> the ICE components. An interesting idea might be to buy
>> something like
>> an Acura RSX Type-S (Wholesale used around between $14k-$16k)
>> and sell
>> the Type-S engines to the import tuner crowd. They go for about $6k
>> right now (I have a Civic, I wanted to do a swap for the
>> longest time).
>> This way you can get a sporty rolling-chassis for just
>> under $10k that
>> would be ready for conversion. As for new, what can we do? Until
>> established I can't see going off and pulling a Tango or a Sparrow,
>> because the R&D cost is so phenomenal. Comments? Recommendations?
>>
>> -Sam Harper
>>
>
--- End Message ---
--- Begin Message ---
Another possibility for isolated BMS communication that no one has mentioned yet is
Bluetooth.
A quick google search for "bluetooth microcontroller" turned up a whole bunch of
products.
(try http://microcontroller.com/news/nsc_lowpower_cr16_bluetooth_256K_flash.asp on for
size)
It talks about a National Semiconductor solution, with chips costing < $10 in
quantities of 1000.
Now I know that there is a lot of development work and support circuitry involved in
getting such a beast from a $7 chip to a useful product, but what do you think?
It solves the high voltage electrical isolation problem.
It solves the spider web of wires problem.
It makes it even easier to interface to both a monitoring computer/PDA and the
charger/controller.
One possible problem is how well it would work in the electrically noisy environment
of an EV.
Just pondering...
Mark
--- End Message ---
--- Begin Message ---
Victor Tikhonov writes:
Lonnie Borntreger wrote:
Here is the cool part. ...
Then you wouldn't be driving "the same car for whole life".
You could have a truck, minivan, car, or whatever you're in the mood for
on any given day.
Lonnie
And pay insurance for as many cars as many body shells you
have, because they are legally different cars. Not so cool.
Victor
That whole insurance thing is rather silly because when I register my 2nd EV
and insure it I get to pay twice as much for insurance (not comprehensive!)
even though I can only drive one car, i'm only one person :-( The body shell
thing just makes the whole thing sillier. Economically speaking i'll
probably have to pull the blazer off the road because I can't afford to have
two ev's insured.
But I would presume we would need some legislation change if the body
swapping ever happened, but if GM is going to do it i'm sure they'll change
it for em. If I change the exterior of my car so it doesnt' have the same
"lines" then I have to have in safety inspected and reregistered in my
state. "lines" would be subjective but i'm sure switching from a minivan to
a pickup body would qualify.
Mark Hastings
'83 S-10 EV Blazer
www.geocities.com/evblazer
--- End Message ---
--- Begin Message ---
[EMAIL PROTECTED] wrote:
>
> I'm looking into building a battery balancer based on Lee's Battery Balancer. I
> can't find something to replace the BatMod for a 6 volt battery with a 72 volt
> input. I'm looking for something around 8 amps. Any suggestions?
Vicor specs the BatMod to work from 6.9v to 16.5v. It actually works
down to 4v at reduced accuracy; they just don't test it at these lower
voltages.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Oops; here's a correction that slipped past the proofreader. You should
use the NO (Normally Open) contacts of the relay, not the NC (Normally
Closed).
Lee Hart wrote:
> Here is a design I have been playing with for about a year...
>
> Charge Current Limiter
> ----------------------
> Wiring diagram:
> lamp
> 120v 150w
> __
> __/ \__
> | \__/ |
> | |
> charger+__________|___||/__|__________battery+
> COM /|| NO <---- was NC, should be NO contacts
> ______
> hot________| |
> | |____
> 120 | | _| relay
> vac | | _| 120vac
> | |____| coil
> neutral____| |
> |______|
> children's "night light"
> (turns light on in darkness)
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
If it works in all that noise, there is another useful side effect. With a
wireless bridge (which are getting cheaper every day) you could actually set
up a system where by as soon as you plug in your car at home, it starts
communicating with your home computer. If there is a problem your computer
inside the house could alert you to it.
Going a step farther, with modern cell phone tech, it would be possible to
plug the BMS into your car phone and have it send a text message to a pager
or e-mail account if there is a problem. Thus it would work anywhere you
are plugged in.
Right now this is pie in the sky, but with the cost of wireless devices
dropping like a stone, it likely won't be for very long.
James
James F. Jarrett
Information Systems Associate
Charlotte Country Day School
(704)943-4562
Beware of programmers who carry screwdrivers. - Leonard Brandwein
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Mark Fowler
Sent: Thursday, February 27, 2003 6:07 AM
To: [EMAIL PROTECTED]
Subject: RE: BMS communication
Another possibility for isolated BMS communication that no one has mentioned
yet is Bluetooth.
A quick google search for "bluetooth microcontroller" turned up a whole
bunch of products.
(try
http://microcontroller.com/news/nsc_lowpower_cr16_bluetooth_256K_flash.asp
on for size)
It talks about a National Semiconductor solution, with chips costing < $10
in quantities of 1000.
Now I know that there is a lot of development work and support circuitry
involved in getting such a beast from a $7 chip to a useful product, but
what do you think?
It solves the high voltage electrical isolation problem.
It solves the spider web of wires problem.
It makes it even easier to interface to both a monitoring computer/PDA and
the charger/controller.
One possible problem is how well it would work in the electrically noisy
environment of an EV.
Just pondering...
Mark
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
> [EMAIL PROTECTED] wrote:
> >
> > I'm looking into building a battery balancer based on Lee's Battery
> > Balancer. I can't find something to replace the BatMod for a 6 volt
> > battery with a 72 volt input. I'm looking for something
> around 8 amps.
> > Any suggestions?
>
> Vicor specs the BatMod to work from 6.9v to 16.5v. It
> actually works down to 4v at reduced accuracy; they just
> don't test it at these lower voltages.
Hi Lee,
I was going to tell Steve the same thing, but I think the problem is
that the BatMod series has a hole in its range of input voltages. See
http://www.vicr.com/products/datasheets/ds_batmod.pdf. The 48 V nominal
BatMod covers 42-60 V, the 150 V nominal goes from 100-200 V. Does
Steve have to pick another DC/DC and run it externally (which you so
cleverly provided for) to run on his 72 V system?
Steve, probably the best source of info on Lee's balancer is Roger
Stockton's excellent site at
http://www.geocities.com/sorefeets/balancerland/.
Chris
--- End Message ---
--- Begin Message ---
Chris Brune wrote:
> Does anyone have any ideas on what the best way to monitor battery
> temperature is? Where should the sensor go? What kind of accuracy
> is really needed?
"Best" under what circumstances? Best price? Best accuracy? Best way to
do it quickly?
Under normal conditions, battery temperature changes very slowly. You
can have a sensor external to the battery that takes half an hour to
respond. In this case, just tape the sensor to the side of the battery
with foam tape (the foam prevents it from responding mainly to ambient
air temperature).
You usually need only one sensor per battery (not one per cell) because
the cells are so close to each other and so similar.
What conditions are NOT normal? A battery positioned with some cells
"out in the breeze" and some insulated by the bulk of the pack can have
a significant temperature differences between cells. If you are doing
very high current charging or discharging, cell temperature can change
very fast when something goes wrong. 100s of amps charging a full
battery, or discharging at dead battery will boil the electrolyte in
minutes. Or a bad cell can run significantly hotter due to a high
internal resistance or partial short. If you expect any of these
conditions, you may need multiple temperature sensors, perhaps as many
as one per cell.
On flooded cells, the electrolyte circulates around inside, evening out
temperatures. You can put a sensor anywhere on the outside below the
liquid level. For faster response, put it in the vent cap or a hole in
the top to directly sense electrolyte temperature. Obviously, such a
sensor has to be VERY acid resistant.
Thermistors are popular temperatur sensors, because they are fairly
cheap and have a large change in resistance versus temperature. The
drawback is that their response is non-linear -- usually a fixed
*percentage* change in resistance per degree C.
Some systems have used glass thermistor beads, running enough current to
self-heat if they do not touch the liquid. It normally touches the
liquid so you get an accurate temperature indication. If the cell water
level is low, the thermistor self-heats and reports an absurd
temperature, telling you that you need water.
Ordinary silicon diodes are a very cheap temperature sensor that is also
very linear at -0.0022 volts per deg.C. But this is such a small voltge
that an amplifier is needed to produce a usable signal. They also have
an offset voltage of about 0.6v that is different for every device; you
must have a calibration proceedure to measure it and subtract it out.
One way to deal with the low signal is to use one diode per cell (6 per
12v battery). This gives you 6 times the voltage to work with, so the
0-5v A/D converter of a microcomputer can read it directly.
A way to get around the calibration problem is to build a circuit that
applies two different measurement currents, like 1ma and 10ma. Take the
difference between them to cancel out the variations between diodes.
On gel cells or AGMs, I like putting the temperature sensor on a battery
post. It responds quicker to the internal temperature of the battery. It
also warns you while driving if you have a loose connection (assuming
something is monitoring the temperature sensors).
Accuracy depends on what you are going to do with the signal. Lead-acid
charge voltage temperature compensation is about -0.003v/deg.C, and
amphour capacity is -1.5%/deg.C. There are also temperature limits that
you don't want to violate, so the battery won't freeze or fry.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Peter Falabella wrote:
> I am interested in buying an EV and would like to check the range
> and top speed advertised...
The only way to check is with a real test drive. Theory can only tell
you what it is capable of -- not what it is actually doing.
> -21 HP Advanced DC FB1-4001 motor
> -18 US Battery batteries (108 vdc)
> -New batteries on Sep 2000 with 3,000 total miles on them.
> -Curtis PMC 1221B-7401 transistor controller
> -K-W BC-20 onboard charger
> -4 speed manual transmission
> -Vehicle weight before conversion 2,550 lbs (is this the culprit?)
> -Range: 20 miles
> -Top speed: 52 mph on the flat, slow to accelerate
These are reasonable components for a small, light vehicle (like a VW
Rabbit, Geo Metro, etc. The controller is probably the main limiting
factor -- it's kinda small for the motor. If this is a heavy, high wind
resistance vehicle (pickup truck), then that would account for the low
top speed, low range, and slow accelleration. It could also be the usual
problems like high rolling resistance tires (chosen for looks), bad
wheel alignment, dragging brakes, poor driving style, etc.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Not sure about your pack size but I bet if you did things as stock it would
be fine and use less amps. If you get caught on a rainy day it might make
the difference. If you have an intermittent setting that would help with
consumption. Lawrence Rhodes....Nice fix....
----- Original Message -----
From: "Richard Bebbington" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, February 26, 2003 1:13 PM
Subject: Mellow Yellow's finally about to hit the road!
> Hi everyone,
>
> Well, at last, my little yellow pickup EV
> is about ready to hit the road!
> ( it's only taken me 2 years... I'm a slow worker :)
>
> I've got the new motor frame Paul C. welded up
> installed, the gearbox is built up, the belt
> drive is nice and tight ( no jumping belt ).
> New rubber bushings in the suspension, the
> power brakes work properly now, and the best
> bit, my upgraded wiper motor works!
> ( there's a story here, read on... )
>
> Tried it all out on the driveway, and can
> creep along beautifully slowly at less than walking
> pace, no infamous Curtis + ADC 9inch "lurching"
> Obviously my motor's got lots of inductance to
> keep the Cursit happy...
>
> So now, the registration document is winging
> its way to the DVLA for them to record it as
> an electric, then I can get my tax disc, MOT
> and insurance! Oh yes, I need to finish the
> charger....and fix the peeling paint on the
> underneath of the floorpan!
>
> The wipers were fun - Mini windscreen wipers
> are driven by a rather pathetic motor. Often
> on old ones it won't move the wipers on a dry
> windscreen. Mine barely moved when the screen was
> wet.... so I took it apart.
>
> It's a permanent magnet motor, with 2 magnets,
> 10 winding slots and 10 comm segments. The winding
> ends are squished onto the comm segments by little
> folded-over parts of the comm - cheap & nasty or what?!
> Also the slots were only half-full, Lucas skimp
> on motor wire too ( they're not referred to as
> "The Prince of Darkness" for nothing... )
>
> I measured the resistances between the comm segments.
> All except 2 were open-circuit! No wonder the motor
> didn't have much power, only 1/5th of its coils
> were connected! The wires looked a bit thin too.
> So I went down to my local electronics store and got
> a reel of magnet wire, deliberately choosing thicker
> wire than the original, so I could rewind it and
> get it to suck more current, thereby making more torque!
>
> 30 turns of old rubbish wire came off from each winding,
> and 20 turns of new twice-as-thick wire went on. Just about
> fitted in there, nice and tight. I re-used the horrid
> folded over bits of comm segment to connect the wires,
> as I wasn't sure if the plastic comm body would like
> soldering. All windings were checked with a DVM, all ok.
>
> Put it all back together, and I now have turbo wipers!
> No trouble moving the wipers across a dry screen, in
> fact they'll probably laugh at inches of snow...
>
> Some data:
>
> the old motor was rated at 14 watts, 12 volts.
> so old motor current would be a bit over 1 amp
>
> re-con motor now uses 3 to 4 amps at 12 volts
>
> speed is probably increased by 50% ( guess )
> ( because I have 20 turns rather than 30 )
> so torque is up by 100 to 200 % ?
> ( current is increased by 100 to 200 % )
>
> Does this sound right for a PM motor?
>
>
> Anyway, I'm now waiting for the DVLA to send me
> my new reg. document, so I can get it all legal
> and then drive it! Let's hope they don't demand
> an inspection to verify it's electric...
> ( I did send some pics of the motor and batteries )
>
> Then it'll be maiden voyage time!
>
> Thanks to everyone who's offered advice on this
> project, especially Paul Compton ( who sold me
> most of the EV bits used in this vehicle )
>
> I'm sure I'll have plenty of charging questions
> when I start using the pickup ;-)
>
> Richard Bebbington
> Electric Mini pickup
> ( finally about to get on the road! )
>
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
>
> The last bike I bought came with a large manual that had a BIG yellow
> triangle on every other page with an exclamation mark and then a
> sentence under it that said something like "Caution, this bike is only
> designed for one person at a time", "Caution, do not try to grab the
> wheels when they are moving", etc.
Who in their right mind would ever do that? Do we have to
implement IQ test one has to pass as a condition for sale?
Victor
--- End Message ---
--- Begin Message ---
Oh, I get it. Replace a bug body and drive train with a heavy
truck but retain a dash with the same VIN - so you still legally have
the same vehicle and save on insurance. OK, now - cool.
What's wrong with this picture?
Victor
Lee Hart wrote:
>
> > Lonnie Borntreger wrote:
> >> Here is the cool part... Then you wouldn't be driving "the same car
> >> for whole life". You could have a truck, minivan, car, or whatever
> >> you're in the mood for on any given day.
>
> Victor Tikhonov wrote:
> > And pay insurance for as many cars as many body shells you
> > have, because they are legally different cars. Not so cool.
>
> No; not if the VIN number was on a part of the car that wasn't changed
> when you change body styles!
>
> Many VIN numbers are on the dashboard, along the bottom of the
> windshield. A *lot* of the car can be changed before you have to disturb
> this area.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
You can now buy these batts.from John Wayland he bought them from me.
Sounds like a good idea. Dennis
--- End Message ---
--- Begin Message ---
I've experimented with X10 phone dialer in my previous hose:
only thing, you also plug the car in to the phone jack in the garage.
When charging was done, I get a call on my cell phone and my own
pre-recorded message tells me the car is ready. You can buy these
dialers and gadgets at home alarm and security stores. Dialing from
dedicated cell won't require plugging into the phone jack.
Actually it was rather fun than truly useful.
Victor
James Jarrett wrote:
>
> If it works in all that noise, there is another useful side effect. With a
> wireless bridge (which are getting cheaper every day) you could actually set
> up a system where by as soon as you plug in your car at home, it starts
> communicating with your home computer. If there is a problem your computer
> inside the house could alert you to it.
>
> Going a step farther, with modern cell phone tech, it would be possible to
> plug the BMS into your car phone and have it send a text message to a pager
> or e-mail account if there is a problem. Thus it would work anywhere you
> are plugged in.
>
> Right now this is pie in the sky, but with the cost of wireless devices
> dropping like a stone, it likely won't be for very long.
>
> James
>
> James F. Jarrett
> Information Systems Associate
> Charlotte Country Day School
> (704)943-4562
>
> Beware of programmers who carry screwdrivers. - Leonard Brandwein
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Mark Fowler
> Sent: Thursday, February 27, 2003 6:07 AM
> To: [EMAIL PROTECTED]
> Subject: RE: BMS communication
>
> Another possibility for isolated BMS communication that no one has mentioned
> yet is Bluetooth.
> A quick google search for "bluetooth microcontroller" turned up a whole
> bunch of products.
>
> (try
> http://microcontroller.com/news/nsc_lowpower_cr16_bluetooth_256K_flash.asp
> on for size)
> It talks about a National Semiconductor solution, with chips costing < $10
> in quantities of 1000.
>
> Now I know that there is a lot of development work and support circuitry
> involved in getting such a beast from a $7 chip to a useful product, but
> what do you think?
>
> It solves the high voltage electrical isolation problem.
> It solves the spider web of wires problem.
> It makes it even easier to interface to both a monitoring computer/PDA and
> the charger/controller.
>
> One possible problem is how well it would work in the electrically noisy
> environment of an EV.
>
> Just pondering...
> Mark
--- End Message ---
--- Begin Message ---
Chris Brune wrote:
>
> From: "Rich Rudman"
> > Mk3s will use 2 more lines for RXD and TXD data flow. And then the Sky's
> > the limit. I hope to also support a Analog Reg as well as the Digi reg
> > on the same bus. So you won't have to have all Digi regs. You should be
> > able to mix and match. For say, a Digi reg in each battery box, for
> > local Temps.
> >
> > I say you need Battery temp and voltage, and which battery you are
> > measuring. The dissapation, will take care of itself.THE rest is fluff
> > Feature creap will then drag you into measuring everything, and sending
> > it down that expensive data buss you have.
> >
> > Evercells NEED temp data badly in summer conditions. I expect that there
> > will be dozzens of new Evercell systems once they get here in volume.
> > This is going to happen and very soon.
> >
> > We will have Digi Regs by June 03 one way or another.
>
> Does anyone have any ideas on what the best way to monitor battery
> temperature is? Where should the sensor go? What kind of accuracy is
> really needed?
>
> Keeping in mind that the sensor needs to be pretty cheap if its going to go
> on every battery.
>
> If the sensor is near a dissipative regulator that isn't going to be good.
>
> LIN based opto-isolated battery voltage monitor almost ready for PCB
> layout... Does anyone think a Palm could be made to talk LIN? Maybe a
> RS-232 to LIN converter?
>
> Chris Brune
1 Degree F is fine. a 5 Deg scatter would be OK, but not real nice, a 10
Deg scatter is about the outside edge of usefulness.
You can spend a lot of cash on sensors. It's really easy to spend a
couple of bucks on a nice stable linear over the -20F to +180 F range
that EV packs are going to see.
What ever the Scale 8 bits is good enough IF all your sensors are
Quality.
The Mk2s use a 10K NTC thermistor. That cost about 66 cents each.
Mouser 334-NTC103. These are great for temp cut outs and Scatter about
50 Deg on my circuit. Good enough for hot/cold. but not much else. The
good ones are $2.05 each ,and are stable 1 Deg C. Getting 1 Deg F, and
some elbow room, may find you looking at a sensor the costs $5.
Lm335z are also a good device. And have the nice feature of reporting
temp in Deg Kelvin. I Use these on the DSP based BLDC drives for my
heatsink temp readbacks. It works but the system noise is a bit abusive,
and I get scatter, but I get predictable results.
For all you bit kickers out there making a BMS system, making one that
works on your desk just a few inches from your PC, is funn and easy.
life gets a bit rougher inside a running EV. You wanna hold 0.01 volts
and know .1 Deg F temps??? Just your sensors are going to cost $10
bucks. Back off to 0.1volt and 1 deg F, and now you can use $2 sensors.
Still you need 8 bits for temp and 10 bits for voltage. Reducing your
voltage range to 8v to 16 V and then saying that window is 8 bits wide.
This gets affordable.
Belting out 50 watts from one end of a Reg while measuring battery temp
to +-1 Deg F on the other end of the same device, is going to get to be
a Pain in the Butt. Remote the sensor?? Ok now you have to wire each
battery, glue on sensors, then reassemble the pack, OH ripped a wire
lead off??? bummer Start over again.
Getting rid of the heat? You DC/DC, or flying cap guys, you too will
have thermal issues from your Switchers and cores. Getting rid of more
than 10 watts for any length of time will require fans, and a remote
load, Just so you won't mess up the sensor for the battery.
Building a BMS won't be easy, or cheap. The little stuff ends up making
a really simple idea turn into a hassel. Many a time I have given up and
just unplugged the RegBuss interface and got on with just a voltage
regulated charge cycle. Sucking data, without dissapation is easy. Once
your data says there's a problem, then it gets a bit harder to solve.
Remeber a BMS is not just a data collection system. You actually have to
do somthing with the data. Control What?? charger,controller, fans, move
power, What???? What is your tool to solve the issues???
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
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