EV Digest 5540
Topics covered in this issue include:
1) Fuel prices...
by "Rush" <[EMAIL PROTECTED]>
2) Re: Vespa Rickshaw.
by [EMAIL PROTECTED]
3) Re: Electric furniture
by [EMAIL PROTECTED]
4) Re: Mk3 Regs
by Eric Poulsen <[EMAIL PROTECTED]>
5) Corbin Gentry electric bike
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
6) Gadget's Triumph
by Reverend Gadget <[EMAIL PROTECTED]>
7) Re: Newbies at 5thEVer 2006
by "Kevin Murray" <[EMAIL PROTECTED]>
8) Re: AC vs. DC - hopefully ending (for now...)
by Dave <[EMAIL PROTECTED]>
9) Performance of my EV
by "Tom Carpenter" <[EMAIL PROTECTED]>
10) Re: How Hot Does a Terminal Get?
by "Chuck Hursch" <[EMAIL PROTECTED]>
11) Re: Corbin Gentry electric bike
by "Michael Perry" <[EMAIL PROTECTED]>
12) RE: the Mark Brueggemann Meter
by Mike & Paula Willmon <[EMAIL PROTECTED]>
13) Re: the Mark Brueggemann Meter
by Doug Weathers <[EMAIL PROTECTED]>
14) humidity vs resistance?
by Jim Coate <[EMAIL PROTECTED]>
15) '81 Jet Electrica & PFC-30 for Sale on eBay
by [EMAIL PROTECTED]
16) Re: AC vs. DC - hopefully ending (for now...)
by Ryan Bohm <[EMAIL PROTECTED]>
17) Re: AC vs. DC - hopefully ending (for now...)
by Doug Weathers <[EMAIL PROTECTED]>
18) Fungus Amongus in Battery H2o
by "Mark E. Hanson" <[EMAIL PROTECTED]>
19) Charger Efficiency
by "Mark E. Hanson" <[EMAIL PROTECTED]>
20) Kelvin resistance measurement (was: How Hot Does a Terminal
Get?)
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
21) Re: Gadget's Triumph
by "John Westlund" <[EMAIL PROTECTED]>
22) Re: How Hot Does a Terminal Get? Comments, in short ,it Doesn't!
by "Bob Rice" <[EMAIL PROTECTED]>
23) Re: the Mark Brueggemann Meter
by "Peter Shabino" <[EMAIL PROTECTED]>
--- Begin Message ---
I was looking at Steve Clunn's web site and see that he has a link to gas
prices
http://tonto.eia.doe.gov/oog/info/gdu/gasdiesel.asp
I use diesel and see that the west coast Spot Price FOB price on 5/5/06 was
$248.10, and on 5/26//06 was $236.20.
Yet 3 weeks ago the price at the pump, here in Tucson, was $2.98 and now it is
$3.01 per gallon. The 'wholesale' price goes down, and the pump price stays
up...
Just another indication of the price gouging, in my opinion, that is going on.
I need to finish my EV!
Rush
Tucson AZ
www.ironandwood.org
--- End Message ---
--- Begin Message ---
<<< http://www.craigslist.org/sfc/mcy/166732661.html Possible conversion
candidate or restoration.
Lawrence Rhodes >>>
Man, that thing is so pink, it even comes with a little girl!
--- End Message ---
--- Begin Message ---
> The thing is that Otmar's loveseat can also go 6 mph. You can creep
> around through crowds at a walking speed, but you can also open it
> up, do a nice wheelie, and have some fun! You can even rotate in place
> quickly enough to shed any extra or unwelcome guests right out of their seats.
>
>
Got a chance to ride on the armrest (Ot was flanked by chicks) - it had more
shabby chic than these flashy-but-slow couches on eBay!
--- End Message ---
--- Begin Message ---
Rich,
Can you provide more detailed specs WRT to the Mk3 regs?
1) How accurate are the voltage measurements?
I see you're using the Atmega88. Assuming you're running the chip @5V.
Without some sort of voltage subtracter circuit, scaling the 18V (max
working V) to 5V using a simple voltage divider, combined with the
10-bit resolution of the onboard A/D, gives you 17.5 mV per LSB, not
accounting for divider inaccuracies, and reference voltage (assumedly
vcc) fluctuations. I'm sure the primary function (bypassing) doesn't
need to be terribly accurate, but for people who would use the Mk3s as a
substitute for checking each battery w/ a voltmeter, +/- 17.5 mV seems
like quite a bit. Do you have a calculated accuracy figure for voltage?
2) Same question, but as applied to temperature measurements, since batt
voltage varies w/temperature
2b) Do set voltage thresholds take into account temperature differences?
I asked about overvoltage protection, and you mentioned that the Mk2
regs blow a fuse (and catch on fire?), but they survive. I was hoping
you could answer this about the Mk3:
3) Is there any overvoltage protection on the Mk3 regs for an open
battery, other than a fuse (which is really an over-current
protection)? Have you tested the Mk3s in a severe overvoltage condition
(full pack voltage)?
4) Is that really a 0.5Ohm resistor in the Mk3 photo on your page? Are
you really bypassing 30Amps? =)
Rich Rudman wrote:
Listers...
Thursday night we had a successful test of the proto type MK3 Rudman
regulators.
--- End Message ---
--- Begin Message ---
Corbin Gentry electric bike at summit, Mt. Washington 1974
I got this picture of this man at the summit of Mt. Washington on an
electric vehicle. Has anyone owned a Corbin Gentry? Seems Corbin was into
more electric vehicles than the VW conversions and the Sparrow.. Nice bit
of EV history.
Lawrence Rhodes
Bassoon/Contrabassoon
Reedmaker
Book 4/5 doubler
Electric Vehicle & Solar Power Advocate
Vegetable Oil Car.
415-821-3519
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
OK! I adjusted the toe-in on the car and set it to a
smidge less than an eighth of an inch, and added some
Kumho LRR tires. My range has increased from 10 miles
to 24 miles to 80% DOD. And I only did one burnout!
about 5 miles of the trip was on the freeway at about
70mph. I'm very satisfied with this car and will be
starting another spitfire in a few days. The next one
will have a 9 inch motor without the tranny. I will be
taking the GT6 apart to paint it but will also
videotape the process of the two cars going together
to show both methods. With transmission and without.
Gadget
visit my websites at www.reverendgadget.com, gadgetsworld.org,
leftcoastconversions.com
--- End Message ---
--- Begin Message ---
I of course missed this event. Is there another one coming anytime soon in
the Raleigh area ?
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 16, 2006 2:33 PM
Subject: Newbies at 5thEVer 2006
Wow! What a weekend! As newbies, this was our first EV event and what a
blast. Too bad about the High Voltage Nationals and Expo rain-out, but,
the fun
was no washout!
It was great to meet everyone. Our first contact was Bob Rice. We drove
by
Warfield Electric early so we would know where to go for the tour. We
went
inside to ask about the afternoon tour. About that time Bob came in to
transfer
batteries from his van to the Led Sled. Then Jerry Warfield came out and
gave us a personal tour of the factory. Then we chatted with Bob and
admired his
vehicle literature while he installed the batteries.
Prior to this weekend, I only knew some of the EV people from Internet
posts
and websites. So I was very eager to meet some of the people I have read
about. I learned that John Wayland certainly holds to his classic form;
after the
announcement and enormous let down of the raceway rain-out, after the
confirmation that the race is dead -- no options -- period. John broke
the cloud of
gloom weighing down on the crowed when he announced from the back of the
room,
"We are going to burn some rubber tomorrow...". I almost cried.
And so it was - May 13, 2006, rubber was burned. The Pep Boys parking lot
gathering was so much fun and very informative. I don't think I have ever
attended a parking lot car show where burnouts were conducted. I guess
the quiet
EV's help with that! Most of the car shows I attend involve standing
around
gawking at parked cars. This one had ACTION! Even the gawking part was
exciting because the machines are not off-the-shelf hot rods. They are
all built by
pioneers in a major turning point in human history.
Many thanks to everyone at this event. It was a real blast!
Ken & Heidi
--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.392 / Virus Database: 268.6.0/341 - Release Date: 5/16/2006
--- End Message ---
--- Begin Message ---
-----Original Message-----
>From: [EMAIL PROTECTED]
>Sent: Jun 1, 2006 9:44 AM
>To: ev@listproc.sjsu.edu
>Subject: Re: AC vs. DC - hopefully ending (for now...)
>
>
>Can someone provide me with a brief description of what "the torque
>constant" of an electric motor means. See bolded lines below.
It is the relationship between electric motor torque and current.
The motor current multiplied by the torque constant gives
the motor torque.
In the standard system of measurement (pounds,feet,seconds)
it is related to the voltage constant of the motor, the number
which when multiplied by the motor rpm gives the back EMF
of the motor, by 5252/746.
Kt=Kv*5252/746 in spreadsheet formula notation. So, it's really a
single relationship which translates voltage times current to
torque times rpm and is comparable to the gear ratio of a
transmission.
I've always heard this number called a constant even though it
is only a constant for a permanent magnet motor. It changes
during motor operation for most other motors, especially series
wound motors.
I didn't see Victor's other post under a different subject title
in which he conceeded to all of Rodger's points until after I
replied under this subject title.
>
>Mike Bachand
>Denver Electric Vehicle Council
>
>In a message dated 5/28/2006 12:10:57 P.M. Mountain Standard Time,
>[EMAIL PROTECTED] writes:
>
>>As you know (mostly info for newbies),
>>The advantage of the high voltage is wide RPM range.
>>The more voltage - the higher RPM before constant
>>torque turns into a constant power.
>
>Not quite so tevarish. The point at which constant torque
>operation shifts to constant power operation is correctly
>determined, in theory, by the maximum power of the
>BATTERY pack. The motor rpm at which this occurs is
>determined by the drive ratio of the drive train and
>the torque constant of the motor.
>
>
>
--- End Message ---
--- Begin Message ---
I have an 1989 Isuzu pu 120v 220 ah u2200 interstate batteries, Curtis
controler FB4100 motor. Now that it is summer I have been more than happy with
the performance. I put it on the road 3rd of March and have been driving it
everyday since then.
I used to drive a 2000 Chev 1/2 ton full size pu that I still have but seldom
drive. I drive the elect when ever I can and the gas truck when I have further
to go. I have not changed my driving habbits just what truck I drive.
I compared my electric bills from Oct Nov Dec Jan Feb Mar and Apr. In the
months before I started charging my vehicle at home I used 867kwh per month
almost to the exact each month. In Mar and Apr I used exactly 967kwh each
month. This may not be to scientific but that was exactly 100kwh each month
more. It used to cost me 150 to 200 dollars per month for gas. Now I spend 30
to 40 dollars per month for gas plus another 9 dollars and 48 cents per month
for the extra 100kwh of electricity.
To say the least I am very pleased with my little electric truck.
Tom
--- End Message ---
--- Begin Message ---
Hi All,
Bringing back an old thread to life and trying to connect to
another old one that I can't find.
I will be re-making on Saturday some of the 2/0 cables for my
EV's pack. I have one post that has turned a 250-degF Celsi-Dot
black, and one that has turned a 200-degF dot. When I was
fooling with this issue a few months back, and was down at the
150-degF level, I replaced each of these cables in turn with my
emergency "bridger" cable that's about four feet long, and did
not have any 150-degF Celsi-Dots turning. So ok, clean up the
posts and regular cables a bit with the wire brush set, get the
mating surfaces shiny as I can, goo up with a generous hit of
Noalox, and put things back together. In each case, I would go
for a few weeks before the Celsi-Dots would start turning again.
Note that during my monthly battery maintenance, I check and
tighten the connections a bit to avoid the lead cold flow
problem. It was not like anything had loosened signficantly when
the Celsi_Dots had turned. These two posts are now triggering,
one at 250-degF and the other at 200-degF. Some other posts in
the pack have triggered some 150-degF dots, but I am not too
worried about that, as long as they don't get much hotter.
Yesterday I took a stab at trying to figure out where the heat is
coming from. Out came the full-pack load tester, a Xmas tree -
looking affair with three big locomotive resistors all immersed
in a big bucket of water, ready to pull ~75A through the 96V pack
for several kW. A few months ago, I had taken a shot at 15A with
the car's heater, but only pulled zeros to three places to the
right of the decimal point (millivolts) when measuring between
the post and the cable lug. I thought at 75A there was a chance
I might get something in the right-most digit, but nooooh,
nothing, even on the hot post. I was going to measure the
post-clamp interface, and also post-to-post, to try and compare
cool-running cable assemblies with warmer ones. I can't measure
the voltage drop from the clamp to the copper cable, since that
is covered with heat-shrink tubing. The only other place I can
think of for heat to come from is inside the battery, and in
fact, this 1-yr old pack has been far more problematic in this
respect than the other two packs I've had in my 11-12 years of EV
driving. I don't know if it has been its somewhat low sgs that
are causing the problem or what.
Anyways, 75A and 000s on the voltmeter display made me think of
Bill Dube' posting where he described the use of a Wheatstone
bridge to figure out the resistance (I have a vague recollection
of this posting). I think it was at least a good two years ago
that he posted that, so I can't find it in my own EVDL archives
extending almost that far back. The archives on the internet,
and there appear to be several different sets, don't seem to lend
themselves to a search for a "wheatstone" bridge. (I did find in
mine and the internet's Brian Hall's reference to one, but that
was a fictitious story.) There are some wheatstone bridges on
EBay that are a reasonable price.
Anyways, hope I'm not making the same mistakes, if any, on these
few new cables. Have to go 50 miles down to the Peninsula where
the tools are. I'd like some nice cool posts for a change.
Chuck
----- Original Message -----
From: "M Bianchi" <[EMAIL PROTECTED]>
To: <EV@listproc.sjsu.edu>
Sent: Wednesday, November 30, 2005 7:57 AM
Subject: How Hot Does a Terminal Get?
> I'm going to put non-reversable temperature-indicator labels on
the terminals
> of my traction pack. I've used this sort of label on equipment
to indicate
> when it is getting overly-hot, even when it isn't hot at the
moment.
> See McMaster.com Part Number 9246T15
>
> The question is: How hot will a _properly_ connected battery
terminal get, at
> say 250 Amps. Clearly one that is badly connected can get to
the melting point
> of lead.
>
> I'm _guessing_ that 170 degrees F might be a reasonable number,
but if anyone
> on the list can say something more certain, I would appreciate
it.
>
> Thanks!
>
> --
> Mike Bianchi
>
--- End Message ---
--- Begin Message ---
Charlie bought the original (?) MC from Corbin... that's the dad not the son
that built Sparrow. When he (Charlie) was here picking up my Freeway
electric, he gave me a post card of the bike at the summit. (I didn't get
the pix, if you sent one, but that may be the same one.)
If I recall, he had to get off and walk for the last stretch, but used the
remaining batt power to pull the bike itself to the top of Mt Washington.
Anyone who's driven to the summit knows what a climb that is.
----- Original Message -----
From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
To: "Electric Vehicle Discussion List" <ev@listproc.sjsu.edu>; "Zappylist"
<[EMAIL PROTECTED]>
Sent: Thursday, June 01, 2006 4:56 PM
Subject: Corbin Gentry electric bike
> Corbin Gentry electric bike at summit, Mt. Washington 1974
>
> I got this picture of this man at the summit of Mt. Washington on an
> electric vehicle. Has anyone owned a Corbin Gentry? Seems Corbin was
into
> more electric vehicles than the VW conversions and the Sparrow.. Nice bit
> of EV history.
>
> Lawrence Rhodes
> Bassoon/Contrabassoon
> Reedmaker
> Book 4/5 doubler
> Electric Vehicle & Solar Power Advocate
> Vegetable Oil Car.
> 415-821-3519
> [EMAIL PROTECTED]
>
--- End Message ---
--- Begin Message ---
Doug Weathers wrote:
> I've been giving this some idle contemplation, and I have a tentative
> plan for building one of these meters. The main thing I dislike about
> Mark's implementation is the use of a panel meter instead of an
> automotive one.
Lee Hart wrote:
It would also be possible to build a digital version, with an X by Y
matrix of LEDs. You need two bar-graph controller ICs, like the LM3914.
One displays battery voltage; the other battery current (voltage across
a shunt). Only one LED lights; the one at the intersection of the row
selected by the voltage, and the column selected by the current. Pick
the color of each LED (red, yellow, green) to correspond to whether it
represents a good, fair, or bad voltage for that particular current.
You could take that a step further and logic OR together all the
combinations that make Green, all that make Yellow and all that make Red.
Then you wouldn't need so many LED's and you'd get an indication of where
you are in between colors by how long one stayed on between cycles of high
demand and no demand.
Mike
Anchorage, Ak.
--- End Message ---
--- Begin Message ---
On Jun 1, 2006, at 1:40 PM, Lee Hart wrote:
It would also be possible to build a digital version, with an X by Y
matrix of LEDs. You need two bar-graph controller ICs, like the LM3914.
One displays battery voltage; the other battery current (voltage across
a shunt). Only one LED lights; the one at the intersection of the row
selected by the voltage, and the column selected by the current.
Very clever! Could I trouble you (or someone) for a simple circuit
diagram that shows how to light an LED only if two outputs are on? A
chip full of AND gates? (I have very little theory and absolutely no
electronics experience.)
More musings on this idea follow, dealing with variations in the design
of the display.
As you drive, the light wanders around inside the display. You could
get voltage and amp readouts by lighting the leftmost and bottommost
LEDs, or by lighting up the whole row and column. Some ASCII graphics
follow (view with monospace font:)
Volts on the vertical scale, amps on the horizontal scale. Lower case
"g", "y", and "r" indicate unlit green, yellow, and red LEDs. Same
letters in uppercase surrounded by parentheses indicate lit LEDs. All
numbers and the configuration of the LEDs have been made up out of thin
air.
Here's the basic version:
g g g g g g g y
g g g g g g y y
g g g g g(Y)y y
g g g g y y y r
g g g y y y r r
g g y y y r r r
g y y y r r r r
y y y r r r r r
The pack is at 208 volts and battery current is 300 amps. This lights
a yellow LED, which alerts the driver that she should start thinking
about getting to an outlet. She can't see the actual values, though.
This display is labeled with volts and amps:
volt
224 g g g g g g g y
216 g g g g g g y y
208 g g g g g(Y)y y
200 g g g g y y y r
192 g g g y y y r r
184 g g y y y r r r
176 g y y y r r r r
168 y y y r r r r r
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
Now the driver can tell the actual volts and amps by reading across and
down from the lit LED. This takes some time, though.
This display is easier to read:
volt
224 g g g g g g g y
216 g g g g g g y y
208(G)g g g g(Y)y y
200 g g g g y y y r
192 g g g y y y r r
184 g g y y y r r r
176 g y y y r r r r
168 y y y r r(R)r r
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
This one's even easier:
volt
224 g g g g g(G)g y
216 g g g g g(G)y y
208(G(G(G(G(G(Y)Y)Y)
200 g g g g y(Y)y r
192 g g g y y(Y)r r
184 g g y y y(R)r r
176 g y y y r(R)r r
168 y y y r r(R)r r
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
The yellow LED at the intersection should be brighter than the others
to make the SoC jump out at the driver.
Here's one that adds extra LEDs to act as volt and amp indicators:
volt
224 g | g g g g g g g y
216 g | g g g g g g y y
208(G)| g g g g g(Y)y y
200 g | g g g g y y y r
192 g | g g g y y y r r
184 g | g g y y y r r r
176 g | g y y y r r r r
168 g | y y y r r r r r
+----------------
g g g g g(G)g g
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
Now I'm looking at the specs for the LM3914 chip and I see it has 10
outputs. Good thing I didn't know that before I started drawing those
ASCII pictures :)
Pick
the color of each LED (red, yellow, green) to correspond to whether it
represents a good, fair, or bad voltage for that particular current.
--
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
--
Doug Weathers
Las Cruces, NM, USA
<http://learn-something.blogsite.org/>
--- End Message ---
--- Begin Message ---
I've been having bizarre problems with my S-10 reporting strange battery
problems. I (somewhat) thought the problem was fixed last fall, but they
have returned. Basically the computer reports the voltage on one
particular battery as changing excessively, or as being too high, while
it's immediate neighbor has an unusually low voltage.
So, as the problem may get worse with rainy/humid weather, my present
feeble theory is that somehow the sense lead to the end of the battery
nearest its suspicious neighbor is somehow flakey. The sense lead has a
30.9K ohm resistor at the end of it where it attaches to the battery cable.
Could a damaged wire or bad resistor be heavily influenced by humidity?
I know the BMS works by briefly connecting a capacitor to a pair of
sense leads, then disconnecting and reading the voltage across the
capacitor. I don't know the value but I'd assume the current flowing in
the sense lead to be rather minute. In turn the resistance would have to
get very high to mess things up so badly. As getting inside the battery
pack is quite a project, I'm wondering if I'm even in the right ballpark
before I go looking.
--
Jim Coate
1970's Elec-Trak's
1997 Solectria Force
1998 Chevy S-10 NiMH BEV
1997 Chevy S-10 NGV Bi-Fuel
http://www.eeevee.com
--- End Message ---
--- Begin Message ---
Please forgive the plug, but I just posted an EV for sale on eBay. It is a
nice Jet Electrica which includes the excellent Manzanita Micro PFC-30 charger.
The item number is:
4646196612
And here is the link:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4646196612
Thanks for looking,
Richard Kelly
'97 NiMH GM S10E
--- End Message ---
--- Begin Message ---
Hi everyone,
Not quite so tevarish. The point at which constant torque
operation shifts to constant power operation is correctly
I bet there are a few non-Russkies that don't know what "tevarish" means
:) Come to think of it, I can't think of a good English
equivalent...pal, friend, bud, ...? :)
-Ryan
--
- EV Source <http://www.evsource.com> -
Summer Special - Free shipping on all orders over $500!
Includes Zillas, WarP and Impulse Motors, and PFC Chargers
E-mail: mailto:[EMAIL PROTECTED]
Toll-free: 1-877-215-6781
--- End Message ---
--- Begin Message ---
On Jun 2, 2006, at 12:07 AM, Ryan Bohm wrote:
I bet there are a few non-Russkies that don't know what "tevarish"
means :)
It would have helped if a correct spelling of the word had been used
(tovarish or tovarishch). Took me a few moments to decide what the
original poster meant.
Come to think of it, I can't think of a good English equivalent...pal,
friend, bud, ...? :)
<http://en.wikipedia.org/wiki/Comrade>
-Ryan
--
- EV Source <http://www.evsource.com> -
Summer Special - Free shipping on all orders over $500!
Includes Zillas, WarP and Impulse Motors, and PFC Chargers
E-mail: mailto:[EMAIL PROTECTED]
Toll-free: 1-877-215-6781
--
Doug Weathers
Las Cruces, NM, USA
<http://learn-something.blogsite.org/>
--- End Message ---
--- Begin Message ---
Hi,
I've been collecting rain water for my batteries (EV, Wind-UPS, golf cart) in
a 30gal cistern tank and it's full of bacteria. Adding a quart Clorox bleach
monthly removes the bacteria but it may be harmful for the US145 batteries in
my Cushman. Is there a chemist who might know what's safe to add to a cistern
to eliminate fungus amongus but not be harmful to batteries? How did people
drink this stuff who live in remote villages anyway?
Thanks,
Mark
---------------------------------
New Yahoo! Messenger with Voice. Call regular phones from your PC and save big.
--- End Message ---
--- Begin Message ---
Date: Thu, 1 Jun 2006 09:45:05 -0700 (MST) Subject: Re: Charger
Efficiency, KWH useage at AC Outlet! From: "Peter VanDerWal" <[EMAIL
PROTECTED]> To: ev@listproc.sjsu.edu Plain Text Attachment [ Download
File | Save to Yahoo! Briefcase ]
> Tom Gocze said that his efficiency wasn't good for an S10 around 1000wh
> per mile. I assume that's measured at the AC line which is the >
appropriate way to measure kWh useage. My electric jeep I sold was > 4000lbs
and measured 452 wH per mile inside the vehicle but reality was > 566 WH per
mile at the AC line. This factors in the 110% you put back > into the
battery (or 120% for NiCads/ NiMh's) and the 90% charger > efficiency. So
with lead batteries their is a 20% overall difference > from reading say an
E-meter VS putting a KWH meter on the AC line which > is the correct way to
compare "apples to apples" when looking at other > vehicle efficiencies and
other means of fossil fuel propulsion > comparisons. Umm that's not
correct. You must put back in 110% of the AMP hours, but in order to do
this, over night, you have to push them in at a much higher voltage than
they come out at. Watthours = Amphours * Volts. The energy you
have to put back into a lead acid pack probably close to 133% of what you get
out, then factor in your charger efficiency (more likely closer to 80% rather
than 90%) and you are now talking 165%. My guess is that if it actually
took 452 whrs per mile from the pack, then it probably needed close to 750
whrs from the outlet. Hi,
I don't think it's quite that bad, I measured DC Whr while driving the jeep at
320 WH per mile and at the AC outlet with a watt-hour meter 452 Wh per mile.
My Cushman is measuring 300 WH per mile out of the outlet.
Does anyone have some real-world data of DC WH used VS *real* AC WH used in
EV's?
Thanks, Mark
---------------------------------
New Yahoo! Messenger with Voice. Call regular phones from your PC and save big.
--- End Message ---
--- Begin Message ---
I don't recall ever posting anything about using a
Wheatstone bridge to measure resistance.
I posted about Lee Hart's "Bat-Bridge" a couple of years
ago. It is Wheatstone-like. It uses a Wheatstone-esk bridge to
compare the voltage on one half of the pack with the other. Quite
effective for flagging a multitude of battery pack troubles before
they become debilitating or dangerous.
You are doing a Kelvin resistance measurement (four wire)
which is something I did post about a few years ago. You turn on the
heater (or the charger) and then measure the voltage across each
interconnect cable by measuring the voltage from post to post. It
should be just a few millivolts. If the post is getting hot, and the
post-to-post voltage drop on the cable is just a few millivolts @10
amps or so, the trouble is inside the battery, just as you have suggested.
Optical temperature sensors are becoming quite inexpensive
these days. You might want to try one of those to find your trouble spots.
Bill Dube'
Yesterday I took a stab at trying to figure out where the heat is
coming from. Out came the full-pack load tester, a Xmas tree -
looking affair with three big locomotive resistors all immersed
in a big bucket of water, ready to pull ~75A through the 96V pack
for several kW. A few months ago, I had taken a shot at 15A with
the car's heater, but only pulled zeros to three places to the
right of the decimal point (millivolts) when measuring between
the post and the cable lug. I thought at 75A there was a chance
I might get something in the right-most digit, but nooooh,
nothing, even on the hot post. I was going to measure the
post-clamp interface, and also post-to-post, to try and compare
cool-running cable assemblies with warmer ones. I can't measure
the voltage drop from the clamp to the copper cable, since that
is covered with heat-shrink tubing. The only other place I can
think of for heat to come from is inside the battery, and in
fact, this 1-yr old pack has been far more problematic in this
respect than the other two packs I've had in my 11-12 years of EV
driving. I don't know if it has been its somewhat low sgs that
are causing the problem or what.
Anyways, 75A and 000s on the voltmeter display made me think of
Bill Dube' posting where he described the use of a Wheatstone
bridge to figure out the resistance (I have a vague recollection
of this posting). I think it was at least a good two years ago
that he posted that, so I can't find it in my own EVDL archives
extending almost that far back. The archives on the internet,
and there appear to be several different sets, don't seem to lend
themselves to a search for a "wheatstone" bridge. (I did find in
mine and the internet's Brian Hall's reference to one, but that
was a fictitious story.) There are some wheatstone bridges on
EBay that are a reasonable price.
Anyways, hope I'm not making the same mistakes, if any, on these
few new cables. Have to go 50 miles down to the Peninsula where
the tools are. I'd like some nice cool posts for a change.
--- End Message ---
--- Begin Message ---
24 miles to 80% DoD makes much more sense. That would be
roughly 150 wh/mile assuming 300 Wh per battery to 100%
discharge, similar to what I calculated before assuming said
modifications.
If you're willing, aeromod the hell out of that car! No
reason you couldn't get that down to 120 Wh/mile or less,
maybe get 45-50 miles to 100% discharge adjusting for
Peukerts.
You can buy sheet metal, and I consider you a god at working
with that shit, so you'd have no problem making
factory-looking rear wheel skirts, grill block, underbelly,
ect.
The efficiency you have now is freaking sick. And you
haven't even tapped aeromods yet, which at highway speeds
are far more significant than rolling resistance. I knew my
choice of car would be an excellent one; glad I took a few
years to look around instead of impulsively buying a Rabbit
or something like it with brick-like aero... Best of all, I
have someone much more competent than I to beat me to the
punch and provide evidence for some of my suspicions about
the potential these cars have as conversions.
http://www.austinev.org/evalbum/630
There she is above. Right now my bitch is propped up on
blocks in the garage, and those pics are a year old. Want to
get her going as an EV this summer, but need to find a job
for that!
God damn, wishing I had money to finish my conversion up.
If I can fit 300V of Orbitals and get ~130 wh/mile, that's
near 100 miles range, adjusting for lower amp draws and
estimating 475 Wh/Orbital(At reserve capacity rate of 95
minutes at 25 amps). But that might be a while down the
road, certainly not my first pack.
If I can't fit that many Orbitals, maybe 13 Deka Intimidator
Group 31s or 13 UB121100s and a Baby Zilla would be a
cheaper route, with similar acceleration performance,
slightly lower top speed(120-ish instead of 140+), 200
pounds less weight, and 70-80 miles range.
At $85 a pop, those cheap Chinesey AGMs are looking more
attractive for my initial conversion than floodies of
similar price. Throw in some Lee Hart regs and a modified
Bonn charger designed to properly execute the end of the
charge, and it might work out alright. If not, most kill
their first pack anyway; I expect to.
Besides, with the AGMs, a contactor controller and
Prestolite might give me fast performance for cheap, albeit
recklessly! Hmm, 0-60 in 9 seconds or less and 100+ mph for
< $2,000? Considering it as a possibility, but need to do a
sanity check and crunch some numbers on this one. That would
kick ass for a first conversion!
Would leave more money to dump into the most obnoxious
stereo system possible so I can blare some Rob Zombie,
Springsteen, AC/DC, or Skynard and perhaps terrorize law
enforcement, security moms, and old people with a seemingly
innocent EV. <g>
Great work Gadget. I hope I can duplicate your results, at
minimum.
--- End Message ---
--- Begin Message ---
Hi Chuck an' EVerybody;
I read your terminal post and go AGGGGRAH! You arent getting all the
power ya paid for! Terminals SHOULD run stone cold,or damn close to it. IF
you are running two ought welding cable, in ,OK ya said that, say a 100-150
amp setup. I don't know your car's operating voltage. I used to check mine
in SOME of my batteries by just reaching back while driving down the
freeway, BEFORE covering them all up,Feeling things. EVerything was OK to
touch, or if I had a hot one, loooking at the soldered, yes, I hear gasps
from the crimping crowd,I soldered ALL the damn lugs and rarely had heating
issues.The TYPE of terminal on the battery can be an issue here. those
THINGS that the battery people lay awake nights thinking up, USELESS for
EV's type amps. Unless you ask US battery, or bust out and recast new real
automotive posts on your new cells. Tony Ascrizzi and I have gotten pretty
good at recasting new posts on a battery. Not for the squeamish, here, as
with a tad too much heat and EVerything melts through the thin battery
top!!Effectively turning your new battery intio scrap!A REAL battery place
can do this with finesse, often better to pay him to do it!
At the risk of starting the dorment soldering vers crimping theme again,
I'll bettya your lugs are crimped? Metal is only human, and looses it's grip
over time, especially if it was a crappy comnnection, to begin
with.Soldering if done right, is perminent, and tight forEVr.It, too, is
tricky. Ya need a HOT torch, a Bernz -o -matic wont hack, or do it! If you
get it TOO hot the solder wicks up the wire, and you havew a buss bar,
rather than a nice flexable cable connecter.So it is sporting, but ya get
good at it with a 120 volt car!<g>The proof is a , maybe 2-5 volt drop under
load. Many EVers are happy with 10-15 volts drop as a fact of life.NO! You
are heating stuff up!Contributing to Global Warming! So check out yur wiring
AFTER a , say, smoky breakstand or a quick ride about town. Those hot spots
you MAY find are hurting your range and operformance. NOTHING should be too
hot to touch! Living warm, like picking up a kitten, is OK, but searing to
the touch. NO! 150 -200 degrees, you have issues to deal with. IMHO.
My two degreez worth.
Seeya at "DC"
Bob
----- Original Message -----
From: "Chuck Hursch" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, June 01, 2006 6:37 PM
Subject: Re: How Hot Does a Terminal Get?
> Hi All,
>
> Bringing back an old thread to life and trying to connect to
> another old one that I can't find.
>
> I will be re-making on Saturday some of the 2/0 cables for my
> EV's pack. I have one post that has turned a 250-degF Celsi-Dot
> black, and one that has turned a 200-degF dot. When I was
> fooling with this issue a few months back, and was down at the
> 150-degF level, I replaced each of these cables in turn with my
> emergency "bridger" cable that's about four feet long, and did
> not have any 150-degF Celsi-Dots turning. So ok, clean up the
> posts and regular cables a bit with the wire brush set, get the
> mating surfaces shiny as I can, goo up with a generous hit of
> Noalox, and put things back together. In each case, I would go
> for a few weeks before the Celsi-Dots would start turning again.
> Note that during my monthly battery maintenance, I check and
> tighten the connections a bit to avoid the lead cold flow
> problem. It was not like anything had loosened signficantly when
> the Celsi_Dots had turned. These two posts are now triggering,
> one at 250-degF and the other at 200-degF. Some other posts in
> the pack have triggered some 150-degF dots, but I am not too
> worried about that, as long as they don't get much hotter.
>
> Yesterday I took a stab at trying to figure out where the heat is
> coming from. Out came the full-pack load tester, a Xmas tree -
> looking affair with three big locomotive resistors all immersed
> in a big bucket of water, ready to pull ~75A through the 96V pack
> for several kW. A few months ago, I had taken a shot at 15A with
> the car's heater, but only pulled zeros to three places to the
> right of the decimal point (millivolts) when measuring between
> the post and the cable lug. I thought at 75A there was a chance
> I might get something in the right-most digit, but nooooh,
> nothing, even on the hot post. I was going to measure the
> post-clamp interface, and also post-to-post, to try and compare
> cool-running cable assemblies with warmer ones. I can't measure
> the voltage drop from the clamp to the copper cable, since that
> is covered with heat-shrink tubing. The only other place I can
> think of for heat to come from is inside the battery, and in
> fact, this 1-yr old pack has been far more problematic in this
> respect than the other two packs I've had in my 11-12 years of EV
> driving. I don't know if it has been its somewhat low sgs that
> are causing the problem or what.
>
> Anyways, 75A and 000s on the voltmeter display made me think of
> Bill Dube' posting where he described the use of a Wheatstone
> bridge to figure out the resistance (I have a vague recollection
> of this posting). I think it was at least a good two years ago
> that he posted that, so I can't find it in my own EVDL archives
> extending almost that far back. The archives on the internet,
> and there appear to be several different sets, don't seem to lend
> themselves to a search for a "wheatstone" bridge. (I did find in
> mine and the internet's Brian Hall's reference to one, but that
> was a fictitious story.) There are some wheatstone bridges on
> EBay that are a reasonable price.
>
> Anyways, hope I'm not making the same mistakes, if any, on these
> few new cables. Have to go 50 miles down to the Peninsula where
> the tools are. I'd like some nice cool posts for a change.
>
> Chuck
>
> ----- Original Message -----
> From: "M Bianchi" <[EMAIL PROTECTED]>
> To: <EV@listproc.sjsu.edu>
> Sent: Wednesday, November 30, 2005 7:57 AM
> Subject: How Hot Does a Terminal Get?
>
>
> > I'm going to put non-reversable temperature-indicator labels on
> the terminals
> > of my traction pack. I've used this sort of label on equipment
> to indicate
> > when it is getting overly-hot, even when it isn't hot at the
> moment.
> > See McMaster.com Part Number 9246T15
> >
> > The question is: How hot will a _properly_ connected battery
> terminal get, at
> > say 250 Amps. Clearly one that is badly connected can get to
> the melting point
> > of lead.
> >
> > I'm _guessing_ that 170 degrees F might be a reasonable number,
> but if anyone
> > on the list can say something more certain, I would appreciate
> it.
> >
> > Thanks!
> >
> > --
> > Mike Bianchi
> >
>
--- End Message ---
--- Begin Message ---
First grab the data sheet at http://cache.national.com/ds/LM/LM3914.pdf
That will get you the basic hookup info for the chip. Now to get a X/Y
display you will need some extra parts. 10 10k resistors (5% 1/4W ok) and 2
octal inverters (pick inverters that have a high state that can drive you
leds (push pull output not OC)).
to hook this up wire both LM3914 as normal except for the LEDs. Now on the X
LM3914 connect the banded (-) side of all leds to this chip (10 leds in each
column x 10 columns). On the Y LM3914 connect the 10 10K resistors between
each output and +V. Also connect each output to one input on a inverter. The
output from the inverter to the (+) side of one row of 10 leds.
How this works is each LM3914 connect its output to ground when its "on". So
for the X row we can just use it as the (-) side of the led. If the output
is "off" the pin will be floating and the LED will not turn on. For the Y
row we need a logic high at the led to turn it on. Since the LM3914 can only
drive a low we need to invert the signal to turn on the led. The pull up
resistor and inverter takes care of this.
If you would like a set of schematics or a board file let me know. I have
the layout tools and can work on it this weekend.
Later,
Wire
From: Doug Weathers <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: the Mark Brueggemann Meter
Date: Thu, 1 Jun 2006 22:33:31 -0600
On Jun 1, 2006, at 1:40 PM, Lee Hart wrote:
It would also be possible to build a digital version, with an X by Y
matrix of LEDs. You need two bar-graph controller ICs, like the LM3914.
One displays battery voltage; the other battery current (voltage across
a shunt). Only one LED lights; the one at the intersection of the row
selected by the voltage, and the column selected by the current.
Very clever! Could I trouble you (or someone) for a simple circuit diagram
that shows how to light an LED only if two outputs are on? A chip full of
AND gates? (I have very little theory and absolutely no electronics
experience.)
More musings on this idea follow, dealing with variations in the design of
the display.
As you drive, the light wanders around inside the display. You could get
voltage and amp readouts by lighting the leftmost and bottommost LEDs, or
by lighting up the whole row and column. Some ASCII graphics follow (view
with monospace font:)
Volts on the vertical scale, amps on the horizontal scale. Lower case "g",
"y", and "r" indicate unlit green, yellow, and red LEDs. Same letters in
uppercase surrounded by parentheses indicate lit LEDs. All numbers and the
configuration of the LEDs have been made up out of thin air.
Here's the basic version:
g g g g g g g y
g g g g g g y y
g g g g g(Y)y y
g g g g y y y r
g g g y y y r r
g g y y y r r r
g y y y r r r r
y y y r r r r r
The pack is at 208 volts and battery current is 300 amps. This lights a
yellow LED, which alerts the driver that she should start thinking about
getting to an outlet. She can't see the actual values, though.
This display is labeled with volts and amps:
volt
224 g g g g g g g y
216 g g g g g g y y
208 g g g g g(Y)y y
200 g g g g y y y r
192 g g g y y y r r
184 g g y y y r r r
176 g y y y r r r r
168 y y y r r r r r
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
Now the driver can tell the actual volts and amps by reading across and
down from the lit LED. This takes some time, though.
This display is easier to read:
volt
224 g g g g g g g y
216 g g g g g g y y
208(G)g g g g(Y)y y
200 g g g g y y y r
192 g g g y y y r r
184 g g y y y r r r
176 g y y y r r r r
168 y y y r r(R)r r
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
This one's even easier:
volt
224 g g g g g(G)g y
216 g g g g g(G)y y
208(G(G(G(G(G(Y)Y)Y)
200 g g g g y(Y)y r
192 g g g y y(Y)r r
184 g g y y y(R)r r
176 g y y y r(R)r r
168 y y y r r(R)r r
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
The yellow LED at the intersection should be brighter than the others to
make the SoC jump out at the driver.
Here's one that adds extra LEDs to act as volt and amp indicators:
volt
224 g | g g g g g g g y
216 g | g g g g g g y y
208(G)| g g g g g(Y)y y
200 g | g g g g y y y r
192 g | g g g y y y r r
184 g | g g y y y r r r
176 g | g y y y r r r r
168 g | y y y r r r r r
+----------------
g g g g g(G)g g
1 1 2 2 3 3 4 a
5 0 5 0 5 0 5 0 m
0 0 0 0 0 0 0 0 p
Now I'm looking at the specs for the LM3914 chip and I see it has 10
outputs. Good thing I didn't know that before I started drawing those
ASCII pictures :)
Pick
the color of each LED (red, yellow, green) to correspond to whether it
represents a good, fair, or bad voltage for that particular current.
--
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
--
Doug Weathers
Las Cruces, NM, USA
<http://learn-something.blogsite.org/>
--- End Message ---
