EV Digest 5621
Topics covered in this issue include:
1) battery box clearance
by Seth Rothenberg <[EMAIL PROTECTED]>
2) Re: hot climate performance??
by Danny Miller <[EMAIL PROTECTED]>
3) Re: DC Motor torque calculations
by "Dave" <[EMAIL PROTECTED]>
4) NEDRA to attend RPM Show at Indy
by "Roderick Wilde" <[EMAIL PROTECTED]>
5) Re: Comparing batteries - was Re: Valence Technology Batteries
by Lee Hart <[EMAIL PROTECTED]>
6) RE: DC Motor torque calculations
by "Roger Stockton" <[EMAIL PROTECTED]>
7) Re: battery box clearance
by Dave Cover <[EMAIL PROTECTED]>
8) Electravan emblem needed
by Rocky Lear <[EMAIL PROTECTED]>
9) Re: Electrics Wow the PIR Crowd Friday Night! (pt. 1)
by "Mike Phillips" <[EMAIL PROTECTED]>
10) Re: DC Motor torque calculations
by Jack Murray <[EMAIL PROTECTED]>
11) Re: Mk3 Reg specs
by "Rich Rudman" <[EMAIL PROTECTED]>
12) Re: Comparing batteries
by "ProEV" <[EMAIL PROTECTED]>
13) Defending EVs - WKTEC
by Dave Muse <[EMAIL PROTECTED]>
14) Re: "DC Inverter" heat pump
by Danny Miller <[EMAIL PROTECTED]>
15) Re: battery box clearance
by "Roland Wiench" <[EMAIL PROTECTED]>
16) Re: "More Electric Vehicles"
by "Death to All Spammers" <[EMAIL PROTECTED]>
17) Re: battery box clearance
by Lee Hart <[EMAIL PROTECTED]>
18) Hosing down batteries
by Chet Fields <[EMAIL PROTECTED]>
19) RE: DC Motor torque calculations
by "Roger Stockton" <[EMAIL PROTECTED]>
20) Re: Hacked Old Mail Truck
by "Rich Rudman" <[EMAIL PROTECTED]>
21) re: hot climate performance??
by Jimmy <[EMAIL PROTECTED]>
22) NEDRA to attend RPM Show at Indy
by "Roderick Wilde" <[EMAIL PROTECTED]>
--- Begin Message ---
I'm planning the new battery box for my car,
probably using (for now) the existing one,
which is set into the floor of the trunk, and
just make a plastic cover. I understand that there
should be some space around the sides to allow for
a bit of expansion, but what about above the batteries?
I plan to have an exhaust fan, so I'm wondering
how much space I need above the batteries for
air flow. Also, would it help to have room for
airflow below or on the sides?
Also, I read on this list two things -
1. It's good to set the batteries in a bed of
Baking Soda (ok, I understand)
2. It's good to have a watertight battery box
with a drain, and wash the batteries.
(ok, I understand)
...and he asked, "But they can't both be right!?"
...and they answered: "You're right also!"
Thanks
Seth
--- End Message ---
--- Begin Message ---
Ripped from Wikipedia:
"At a 100% charge level, a typical Li-ion laptop battery that's full
most of the time at 25 degrees Celsius, will irreversibly lose
approximately 20% capacity per year. This capacity loss begins from the
time it was manufactured, and occurs even when the battery is unused.
Different storage temperatures produce different loss results: 6% loss
at 0 °C, 20% at 25 °C, and 35% at 40 °C. When stored at 40% charge
level, these figures are reduced to 2%, 4%, 15% at 0, 25 and 40 degrees
Celsius respectively."
But on the other hand warm batteries have more capacity than cold ones.
This is especially true of lead acid batteries, gelled or flooded.
Dany
David Roden wrote:
On 5 Jul 2006 at 1:15, mike phillips wrote:
what happens to the performance, range, life, etc of an EV when operated
in Phoenix, Arizona conditions?
Obviously cooling is an issue, for the motor and the controller. But for
the typical commuter EV, the most annoying problem IMO is the hit in battery
cycle life. High operating temperatures are quick death for nicad and NiMH
batteries, and will significantly shorten the life of lead batteries. I
don't know about the effect on Lithium batteries.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Jack Murray" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, July 04, 2006 11:18 PM
Subject: Re: DC Motor torque calculations
Only a SHO
taurus has manual trans, all the normal cars are automatics, which of
course, a torque converter allows idling, but doesn't seem appropriate for
electric motor, not to mention all the extra weight.
Early Taurus with 4 cylinder engines were available with 5 speed manual
transmissions
David C. Wilker Jr.
United States Air Force, Retired
--- End Message ---
--- Begin Message ---
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
--- End Message ---
--- Begin Message ---
Michaela wrote:
> In comparing alternative battery chemistries: Do those batteries
> suffer some kind of Peukert's effect too?
Peukert's equation affects the amphour capacity of a battery. It says
that the higher the current, the lower the amphours. It applies
primarily to lead-acid batteries.
Ohm's law affects the voltage you get from a battery. It says that the
higher the discharge current, the lower the voltage (due to internal
resistance) -- but it does not affect the amphour capacity. It affects
all batteries (including lead-acid).
As a practical matter, what matters is how much *energy* you get out of
the battery; not just its voltage or amphours. So for every battery, you
have a graph of energy versus discharge current, and they all deliver
less energy as the discharge current is increased. This graph is the
combined effects of both Peukert's and Ohm's effects.
--
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 ---
Jack Murray wrote:
> > Only a SHO taurus has manual trans, all the normal cars
> > are automatics, which of course, a torque converter allows
> > idling, but doesn't seem appropriate for electric motor,
It isn't ideal, since an EV doesn't otherwise need to idle its motor,
but it does address the issue of driving your accessories in a tried and
proven way.
My only caution would be that if you do idle the traction motor,
*please* do not use a Curtis 'C' version controller! The 'C' versions
are also known as the "whiners" because at low throttle/duty cycle they
drop the switching frequency to a very audible 1.5kHz. If you use one
of these controllers and idle the motor, then whenever the key is on and
the car is still there will be an annoying high pitched whine emmanating
from under the hood. You will not hear the motor idling, but you and
everyone nearby will hear the Curtis whine until you apply more throttle
and get the vehicle moving.
> > not to mention all the extra weight.
What extra weight? Do you mean the weight of retaining the torque
convertor?
I think that if you compare the weight of the torque convertor to the
weight of individual electric motors (and controls!) and the associated
bracketry required to drive your accessories seperately you will find
that it is really quite an elegant solution. These individual accessory
motors will take a fair bit of space under the hood, and smallish HP
motors of decent quality (read efficiency) can be difficult to find.
You have mentioned power steering, and AC, and if you eliminate the
torque convertor you will need an electric pump for the tranny (without
a pump, the pressure takes a bit of time to build each time you try to
start moving and this results in a very unimpressive driving
experience). It may also result in accelerated wear and tear on the
tranny clutches as they slip until pressure builds, and if you stomp on
the throttle such that pressure builds too suddently, you can pop a seal
(o-ring) on a clutch piston, or possibly do more serious internal
damage.
If you are concerned with efficiency, you may want to look for a more
appropriate conversion candidate. The Taurus is heavy, and if all you
can get is an auto model (and the auto tranny in these was not
considered reliable even in ICE trim), then you are immediately looking
at a heavier and somewhat less efficient conversion unless you ditch the
tranny. Ditching the stock tranny on a FWD vehicle and replacing it
with something else raises the conversion challenge to a whole new
level. If you go with an AC drive from Victor @ MetricMind, you have
the option of using a matching fixed reduction transaxle instead of the
stock tranny, but otherwise I think your options are limited to swapping
the auto tranny for a compatible manual unit (far easier to start with a
manual tranny car).
Perhaps an Escort or Focus with 5-speed tranny would be a better
starting point?
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Seth
I'm building mine right now and am addressing these issues too. The way I'm
tackling it is by
building my battery boxes out of 1/4 inch HPDE which I will support with a
metal frame. I'll have
the metal frame painted, maybe sprayed with bed liner. I'm going to have about
an inch of air
space on the top. I'll have squirrel cage fans supplying air to this area. I
have provision for
airflow between the cells down to another airspace in the bottom of the battery
box. I'm going to
drill vent holes in the bottom for the outlet. This will allow the byproducts
of cell venting to
exit safely out the bottom. The battery boxes and everything in them should be
safe from
corrosion.
If I plan it right, the vents will provide passive venting while driving down
the road (thanks to
Venturi.) I should also be able to open the top and hose my cells down to clean
them off. I'm not
worrying about neutralizing the electrolyte, the occasional rinse will clean
things up. The HDPE
should protect any metal surfaces. Pictures to follow when I make progress.
Dave Cover
PS I was reading a DMV document that implied that battery boxes should have
provision to prevent
all that dangerous hydrogen from exploding when you flip on the light switch. I
belive you can use
the same technique they use for miners lamps and hot water heaters. Use a fine
mesh screen over
the outlets to block the flame from getting in your battery box.
--- Seth Rothenberg <[EMAIL PROTECTED]> wrote:
>
> I'm planning the new battery box for my car,
> probably using (for now) the existing one,
> which is set into the floor of the trunk, and
> just make a plastic cover. I understand that there
> should be some space around the sides to allow for
> a bit of expansion, but what about above the batteries?
>
> I plan to have an exhaust fan, so I'm wondering
> how much space I need above the batteries for
> air flow. Also, would it help to have room for
> airflow below or on the sides?
>
> Also, I read on this list two things -
> 1. It's good to set the batteries in a bed of
> Baking Soda (ok, I understand)
> 2. It's good to have a watertight battery box
> with a drain, and wash the batteries.
> (ok, I understand)
>
> ...and he asked, "But they can't both be right!?"
> ...and they answered: "You're right also!"
>
>
> Thanks
> Seth
>
>
--- End Message ---
--- Begin Message ---
I need an Electravan emblem for the hood on my 81 Courier electric truck. Part
of the original is missing. Appears to be the same as the emblems on the
fenders which ar OK. the emblems I have are flat black one color but could be
weathered. Does anyone know how the original emblems were finished out , if at
all?
Rocky
--- End Message ---
--- Begin Message ---
In electric vehicles the data that Hawkers last is lacking. They are
tough in some ways. Current deliverey is great. But I think they are
not the best choice. Cor is trying some Chinese agm's. His success or
failure will determine my next lead acid purchase. They are vastly
cheaper to buy we just need to look into the longevity.
I own 104 Hawkers. $7k.
Also, Hawkers are not as well sealed as some batterys I've seen. The
good news is that they can be watered.
Mike
--- In [EMAIL PROTECTED], [EMAIL PROTECTED] wrote:
>
> Lawrence-
> I keep hearing how Hawkers last a long time.
> Yet where's the evidence?
> Wayland's Hawkers are new.
> His last set lasted a year.
> My 96v set in my 1921 Milburn were supposedly dead when I got them,
but they seemed good enough for the distances I needed, so I'm not
rushing off to get new batteries yet. Parenthetically, after leaving
Wayland's pre-dragrace juice bar with my Milburn on Friday, I made the
big mistake of plugging the Hawkers in for recharge...well, that was
6pm...I came back the next morning around 11am to find the batteries
sizzling drawing over 5amps at 119v----the batteries were quite hot,
hissing and the cases bulging.... Still, after rewatering, they still
seem to have some capacity at least. Longevity certainly has been
compromised. Time to at least put a timer on my 13-25amp Vicor
charger setup...
>
>
> I would like to see examples of Hawkers as a long lasting battery
compared to the alternatives. I like the batteries, but wouldn't
spend that kind of money in the face of the usual alternatives and the
rebadged Hawkers at Batteries Plus.
>
> -Myles Twete, Portland, Or.
> -------------- Original message --------------
> From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
>
> > More help for the rest of us from the racers. The internal
interconnect
> > story is of great concern to the rest of us. Anything that helps
battery
> > durability is a plus. The fast charging is how I think Hawkers are
lasting
> > so long. In the real world we punish our batteries a little at a
time over
> > years. I suspect it's the low power battery chargers we use. I
suspect if
> > we concentrated on the charging side we'd improve efficiency &
longevity.
> > Thanks John. As always you are a great story teller..........Lawrence
> > Rhodes........
> >
>
--- End Message ---
--- Begin Message ---
Hi Roger, yes, the weight of the converter and the trans. The stock
taurus trans IS a weak point, and my intention is to eliminate it. My
latest thought without looking at it yet is to modify the trans to keep
the differential portion of it. The idea would be to use a single
accessory motor that spins the existing belt, and can be sized and run
at a constant rpm to max its efficiency.
My question is how did Roderick do the conversion on his taurus, waiting
to hear about that, guess he's on vacation.
One point in doing a taurus is exactly because it is NOT a small car.
Best Regards,
Jack
Roger Stockton wrote:
Jack Murray wrote:
Only a SHO taurus has manual trans, all the normal cars
are automatics, which of course, a torque converter allows
idling, but doesn't seem appropriate for electric motor,
It isn't ideal, since an EV doesn't otherwise need to idle its motor,
but it does address the issue of driving your accessories in a tried and
proven way.
My only caution would be that if you do idle the traction motor,
*please* do not use a Curtis 'C' version controller! The 'C' versions
are also known as the "whiners" because at low throttle/duty cycle they
drop the switching frequency to a very audible 1.5kHz. If you use one
of these controllers and idle the motor, then whenever the key is on and
the car is still there will be an annoying high pitched whine emmanating
from under the hood. You will not hear the motor idling, but you and
everyone nearby will hear the Curtis whine until you apply more throttle
and get the vehicle moving.
not to mention all the extra weight.
What extra weight? Do you mean the weight of retaining the torque
convertor?
I think that if you compare the weight of the torque convertor to the
weight of individual electric motors (and controls!) and the associated
bracketry required to drive your accessories seperately you will find
that it is really quite an elegant solution. These individual accessory
motors will take a fair bit of space under the hood, and smallish HP
motors of decent quality (read efficiency) can be difficult to find.
You have mentioned power steering, and AC, and if you eliminate the
torque convertor you will need an electric pump for the tranny (without
a pump, the pressure takes a bit of time to build each time you try to
start moving and this results in a very unimpressive driving
experience). It may also result in accelerated wear and tear on the
tranny clutches as they slip until pressure builds, and if you stomp on
the throttle such that pressure builds too suddently, you can pop a seal
(o-ring) on a clutch piston, or possibly do more serious internal
damage.
If you are concerned with efficiency, you may want to look for a more
appropriate conversion candidate. The Taurus is heavy, and if all you
can get is an auto model (and the auto tranny in these was not
considered reliable even in ICE trim), then you are immediately looking
at a heavier and somewhat less efficient conversion unless you ditch the
tranny. Ditching the stock tranny on a FWD vehicle and replacing it
with something else raises the conversion challenge to a whole new
level. If you go with an AC drive from Victor @ MetricMind, you have
the option of using a matching fixed reduction transaxle instead of the
stock tranny, but otherwise I think your options are limited to swapping
the auto tranny for a compatible manual unit (far easier to start with a
manual tranny car).
Perhaps an Escort or Focus with 5-speed tranny would be a better
starting point?
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Yea.... What do you want to know??
I have 15 running in my Fiero in the drive way.. and I will be installing
15 on the PiPrius Kit's pack of used and abused Hawker Aero AB 26.
We have been keeping the specs kinda under raps while we are debugging the
Code and adding Features. They do a LOT of sweet things.
They have to act as our feature list states..or I can't ship them and still
look myself in the mirror!!
So I can tell you what you need to know and ask what else you would like.
But..until I have stack that works basicly flawlesslly... I am not
publishing the entire specs.
We have about 2 killer features that were not in the first list. More are
sure to follow.
There is a a page on my site devoted to MK3. maybe I need to update some
items. I have 2 clients waiting for product. I don't want any more on the
list until I have the units working as designed.
The Fiero is running at 4800 Baud.. not good enough for the Big time. The
PiPirus pack will run at 9600 as advertised. Let me get a week on them. Then
we do photo shoots and take orders.
Lordy....
17.5 Mv per tick... these are not CPU trim voltage regulators... Even 3
digits of accuracy is over kill. Calculated accuracy?? they seam to follow
my DVM within about 10 Mv. Good enough for this kind of work.
Then temps are about +- 2.5 Deg F. also good enough for this kind of work.
The temp sensor is a LM35. No temp comp control loops are being used at
this time. That still is in the future. We intend to do so.
Over voltage Pro.. 5.6 V Zener on the Micro pin... Fuse across the whole
mess. The fuse opens... and saves the Mk2B regs. This has happened twice...
and the Reg lived to tell about it. I have not had a pack open under a Mk3
yet. So I don't know. There was NO fire on the regs. The splattered lead
was from the battery opening!!! That was in Race mode...I lost....
The 0.5 ohms is part of the programable PWM linear region Fet bypass
circuit. No we don't drop the entire load across the 1/2 Ohmer....it is a
current sense across the FET that Does drop all the power.
We can program the max dissapation current. But we don't yet. It's still
resistor fixed... and it's set to %100 Pwm right now.
We don't even have the QC chart written yet.. I we don't know what is a good
reg and a bad reg in the precision and accuracy specs yet. They do what I
need them to, and they are close enough for me to believe the data, that I
check by hand.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Eric Poulsen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, June 30, 2006 2:17 PM
Subject: Mk3 Reg specs
> I know Mr. Farver had a generic answer to this question (from a design
> standpoint), but does anyone have detailed specs for the actual Mk3?
>
>
> Eric Poulsen wrote:
> > 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 ---
Hi Michaela,
What I always wanted to know:
My T-125s have a 20hr rate of 240AH. Now: I know that, due to Peukert's
law I am going to get just about 1/2 of that for driving.
In comparing alternative battery chemistries: Do those batteries suffer
some kind of Peukert's effect too?
With lithium polymers, the effect is pretty minor.
Kokam's were rated at 1C, so a 100 amp-hr cells give 100 amps for 60
minutes.
Looking over Kokam's literature, there is a graph at
http://www.kokamamerica.com/kokam_catalog.pdf page 14, second one down,
right hand side. This is the discharge graph for High Powered Large Cells
giving percent of capacity at different C rates.
In this graph (assuming a 100 amp-hr cell):
.5C (50 amps) gives you 100% of rated capacity.
1C (100 amps) gives you 95%.
2C (200 amps) gives you 92%.
8C (800 amps) gives you 84%.
In our testing with the old style 70 amp-hr cells Kokam cells, we got:
100% at 1C(70 amps)
82% at 10C(700 amps).
http://www.proev.com/P1Batt.htm
Or - to rephrase the question: How many
LiIon or Lipo Ah's would I have to get in order to have at least as much
avaiable as my T-125s provide?
I would guess the 100 amp-hr cells would be about right but it is very
current and type of driving dependent.
I understand that LiPos or LiIons would save much weight, but if I would
shell out significant money, it should make an impact on range too.
Weight has a huge impact on range in real world driving where it is
necessary to accelerate mass and then waste the energy in braking.
Hope this helps.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
With the arrival of the movie "Who Killed The Electric Car", I have been
discovering the topic of EVs raised on numerous discussion boards around
the net - and a lot of disinformation is being promulgated.
With a wider release of the film coming up, this would be a good time
for everyone here to look for discussions to participate in.
Dave Muse
--- End Message ---
--- Begin Message ---
That does sound promising. It's also got an impressive SEER value.
That's the same strategy as the "Mr Slim" A/C units that they keep
running late night commercials for. Mr Slim only has like a 10-13 SEER
though. Man, 16.6-17.6 is pretty good!
The inverter controls really sound promising for DC/DC conversion.
Still, it's worrying in that it may require a higher DC voltage than
your battery pack. Hard to say but 120VAC through simple rectification
produces 170VAC. Certainly they must have some sort of power factor
correction, in fact they may have designed it to change the DC voltage
of the rail depending upon load.
Danny
[EMAIL PROTECTED] wrote:
Perusing eBay, I found an item that brought up a few questions.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280003104238 is a heat pump
that uses a "DC inverter", so it rectifies 120VAC, smooths its out to DC, then
runs it through a 3-phase inverter. If you could jump to just DC input
(especially a range of DC voltages), it might make a nice candidate for cooling
and heating a conversion.
--- End Message ---
--- Begin Message ---
Hello Seth,
My battery box for my Trojan T-145's is 12 inches high in the inside. There is
a 1/2 inch space around the top lip of the battery, but below this lip, the
space is about 3/4 inch.
The top of my battery case is 2 inches from the inside of the cover, and the
top of the post terminals are about 1 inch from the cover.
The inside of the battery box, is coated with that epoxy coating for redoing
sinks and tubs that you can get from Home Depot.
When these batteries are tight together at the top lip, the battery sides are
about 1/2 inch apart.
In one corner close to the top of the box, I have a 2 inch hole cut in for a 2
inch 90 degree PVC plastic elbow, (the high pressure type for water). A 2 inch
PVC pipe is connected to this in goes down below the car. This is the input
air for the box.
I stuff this pipe, with a bulk air filter, which is a 3M type for a swamp
cooler.
The output pipe is install in the opposite corner, which is pipe to a 1/4 inch
thick acid proof flexible PVC pipe. This pipe is then connected to a all
plastic totally enclosed fan in about 100 cfm range.
The fan I used, is a square muffin fan, where it is easy to bolt on a 1/4 inch
plastic sheet, that has a 2 inch pipe stud epoxy glue to it. The PVC flex hose
then can slip over the fan inlet and outlets.
The fan is a 120 VAC type, which is control by a pressure switch, that detects
the pressure/vacuum in the lines. A 3-position toggle switch is used to turn
on the fan, and when fan is running, I than switch to the auto position, so the
vacuum switch is in line with the fan circuit.
If you loss this pressure or the fan turns off, the vacuum switch shuts down a
AC magnetic contactor, which provides power to the charger. Or you can have
the vacuum switch control a DC contactor between the charger and the batteries.
You can get these industrial vacuum switches, from a plumbing and heating
supply house which are normally use for detecting air flow in a heating system.
Do not use a thin plastic hose for ventilating you battery boxes. I had
battery fumes eat these type of hose right up.
Only exhaust the battery boxes, Do not install fans on the input side. This
prevents the battery fumes to push out of the boxes.
The exhaust fan outlet, also go below the car on the farthest opposite side and
points down and back like a exhaust pipe.
One advantage of a battery box exchange air system, is that it keeps the
batteries very clean. According to the Hydrocell company, (which you need 3
inches of space above the battery caps to the cover), that a lot of fresh air
exchange will work just as good as some Hydrocells.
I do set the enclose batteries on a 1/2 inch layer of baking soda. But there is
no drain. I do not wash my batteries down by flooding them down with water.
I use a Whitaker Battery Spray cleaner, that goes on clear and does not leave a
white mess like baking soda does.
Just wipe the batteries down with paper towels. I don't remember the last
time I done this. Today the batteries are still super clean.
Roland
----- Original Message -----
From: Seth Rothenberg<mailto:[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu<mailto:ev@listproc.sjsu.edu>
Sent: Wednesday, July 05, 2006 4:46 AM
Subject: battery box clearance
I'm planning the new battery box for my car,
probably using (for now) the existing one,
which is set into the floor of the trunk, and
just make a plastic cover. I understand that there
should be some space around the sides to allow for
a bit of expansion, but what about above the batteries?
I plan to have an exhaust fan, so I'm wondering
how much space I need above the batteries for
air flow. Also, would it help to have room for
airflow below or on the sides?
Also, I read on this list two things -
1. It's good to set the batteries in a bed of
Baking Soda (ok, I understand)
2. It's good to have a watertight battery box
with a drain, and wash the batteries.
(ok, I understand)
...and he asked, "But they can't both be right!?"
...and they answered: "You're right also!"
Thanks
Seth
--- End Message ---
--- Begin Message ---
> A friend of mine who is registered with the IEE (in the UK) sent me
> this this morning in an email. I haven't watched it all yet, but the
> tip here is to fast forward in the presentation to about 14 12
> minutes since the first bit of the broadcast seems to be the admin
> guy setting up the webcam!
>
> http://www.iet.tv/search/index.html?spres=4615
>
All I knew about Manchester was that they have a soccer team, but now
I know they have lecturers that rival sleeping pills! Seriously, I
watched the whole thing and even understood most of what he was
talking about - when will he have those "more electric airplanes" up
and running?
--- End Message ---
--- Begin Message ---
Seth Rothenberg wrote:
> I'm planning the new battery box for my car, probably using
> (for now) the existing one, which is set into the floor of the
> trunk, and just make a plastic cover. I understand that there
> should be some space around the sides to allow for a bit of
> expansion, but what about above the batteries?
Here are some things to consider for battery boxes:
1. Strength
Batteries are heavy. The box needs to be strong enough to safely support
them, even in case of a crash. A good rule of thumb is that the box
should hold the batteries even if the car was rolled, tipped upside
down, or suffered an impact of 4 Gs forward, and 2 Gs in any other
direction.
2. Corrosion resistance
Batteries all leak to some degree, regardless of whether they are
floodeds or sealed. The chemicals inside are highly corrosive. Wood and
bare steel are not appropriate -- they will be slowly destroyed. Paints
and coatings are unreliable -- they crack and chip. Thick coatings,
plastic liners, fiberglass, or corrosion-resistant metals like stainless
steel or aluminum are preferred.
3. Shock hazard
Most pack voltages are high enough to be lethal. The battery box needs
to seal them up well enough to prevent accidental contact by kids,
animals, or careless onlookers.
Leaking batteries also cause ground faults, i.e. paths for current to
flow to the vehicle's chassis. These can produce shock hazards and trip
GFCIs (Ground Fault Circuit Interrupters).
4. Temperature
Like people, batteries work best when kept at reasonable temperatures.
In some climates, this requires some kind of heating or cooling system.
It may be sufficient to insulate them with an inch or so of styrafoam
insulation, and depend on their high weight to act as a "flywheel" to
protect them from temperature extremes. Or, you may need a fan, heater,
or cooler if your climate has very hot or cold temperatures.
5. Ventilation
Batteries can produce hydrogen gas. Floodeds produce a lot, but sealed
batteries will also gas if overcharged. So, the battery box must not be
air tight; you must provide vents and sometimes even a fan to prevent
gas from being trapped inside.
6. Other
Batteries made with flat plates tend to swell as they age. If you snugly
pack new batteries in a battery box, you may find them swollen and
nearly impossible to remove when they need replacement. It's a good idea
to provide some method to force them out (a removable side to the bot, a
strap left under them to lift them out, etc.)
If you can prevent them from swelling with a very strong battery box,
this will help life somewhat. But be warned that the pressure can get
quite large.
> 1. It's good to set the batteries in a bed of Baking Soda
You can, but this seems extreme. I'd work harder to prevent the leaks in
the first place.
> 2. It's good to have a watertight battery box with a drain, and wash
> the batteries.
I've done this, too. But generally, I leave the drain hole open in the
bottom, because you may also get condensation, spills from watering, or
rain in there. You definitely don't want your battery box to become a
pool!
--
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 have read several references now to hosing down flooded batteries to clean
off the acid spray buildup. When this is done, do the interconnect cables need
to be removed? What stops the batteries from shorting out while this is done?
Or is this not a concern?
Chet
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Jack Murray wrote:
> The idea would be to use a single accessory motor that spins
> the existing belt, and can be sized and run at a constant rpm
> to max its efficiency.
So, you seem to be betting on being able to find a single motor in the
~5HP range that will run enough more efficiently than your traction
motor to make a difference. If we do a bit of back of the napkin
figuring, let's say the accessory load is about 5hp (3.7kW). At 85%
efficiency (about the best you would get even from a dedicated motor),
this is 4.4kW input from the battery. At 60% efficiency (about what
your traction motor might run at when idling with only the accessory
load), 6.2kW is required from the battery. If we round up the
difference to an even 2kW, then this means that every time you stop at a
light, etc. for about 2min and just idle the accessories you will
consume about 67Wh more from the battery using the traction motor. This
translates to about 15 stops (30min of idling!) to consume just 1kWh of
additional energy from the pack.
While driving, the traction motor efficiency will typically be nearer
its peak (about the same 85% as the best accessory motor), and the
difference becomes much less.
> The stock taurus trans IS a weak point, and my intention is to
> eliminate it. My latest thought without looking at it yet is
> to modify the trans to keep the differential portion of it.
The accessory motor and its mounting bracketry, etc. will likely [more
than] offset any weight savings associated with eliminating the torque
convertor and guts of the tranny.
You would likely need to modify the tranny such that it offers some
fixed reduction in addition to the reduction offered by the
differential. Assuming you use a DC traction motor, you are likely to
lose more efficiency by going to a single fixed reduction than you would
ever gain from running the accessories with a more efficient dedicated
motor. Since the power required to move the vehicle is significantly
greater than that required to spin the accessories, losing a few percent
in drivetrain efficiency can easily amount to a greater amount of power
being drawn from the pack than the difference between driving the
accessories from the traction motor vs a dedicated accessory motor.
You will also incur the additional cost of reversing contactors as
removing the guts of the tranny will cost you the mechanical reverse
gear.
If you are determined to do a Taurus and not use the auto tranny, it may
definitely be worth seriously considering the option of transplanting a
manual FWD tranny into it, if not one from another Taurus, perhaps one
from an Escort or Focus.
> One point in doing a taurus is exactly because it is NOT a
> small car.
But, it will effectively be one when you are done. You are starting
with a heavy vehicle that has limited payload capacity (unlike, say a
pickup), and when you are done, even if you have managed to retain the
back seat you will most likely be at or over the GVWR unless you either
use exotic batteries or have a very short range requirement. So, at the
end of it, you will have a largish appearing vehicle that can probably
seat a maximum of 2 people safely. (Insurance around here tends to be
void if you are caught with a vehicle operating over GVWR.)
Good luck,
Roger.
--- End Message ---
--- Begin Message ---
They wouldn't fit because:
You were stuck with using the same layout that the Van came with.
The design was to use a independant rear suspension, and the battery boxes
were laid out where any real drive train would be.
The point is.. When doing twin 500 Hp drive trains.. inventing them is a
really hard thing to do. Espeically with Cameras up your butt and a rather
limited budget.
If we really were hunting for sub 10 seconds like we were bragging about..
thought about what to use and where to get it would have been different.
Searching a wrecking yard for a drive train that was intended fro 100 to 150
Hp is a fools errand Rod... and you know it. Or you do now.
Where to fit two narrowed 9s.. or better.. should have taken first place...
not as after thought.
We did pretty good with what we had..
We all know how to go faster now don't we????
Madman
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, June 30, 2006 2:08 PM
Subject: Re: Hacked Old Mail Truck
>
> In a message dated 6/30/2006 11:15:20 A.M. Pacific Standard Time,
> [EMAIL PROTECTED] writes:
>
> "A pair of 9 inch rear ends and a pair of TH400 trannies and we would not
> have had any real drive train issues on Gp But.. it would have been a
> totally different EV..Not a hacked old Mail truck like the TV producers
> wanted."
>
> Look Rich, you know damned well that these items will not fit in the tiny
> room alloted in "GP".
>
>
> Why wouldn't a narrowed 9" have fit?
> I've seen them as narrow as appx. 24inches and as wide as 6 feet.
>
> Ben
>
--- End Message ---
--- Begin Message ---
The high heat has mixed results. I have used the 12v flooded marines and
they only lasted a couple years. Not even the trojan 8 volts do very well.
I have had Gel packs pop like popcorn when I tried to dump more than 200
amps when it is over 100F (was it the heat?). The best results for me has
been the tojan T125s, I have had packs that lasted over 6 years, I think
because they can endure the summers. The summer is the hardest on these
batts and it is because the battery temp is so high even before you start
to charge. It is easy to undercharge if you have a temp threshold. I
actually stop before a full charge and then let the pack cool down and do
a finish charge preferably at night when the temp gets down in the 80s.
For this reason flooded batteries are the easiest to take care of, this
goes for flooded NiCads too. Of course an advantage is if you let a low
pack set for about 15 min you will get out another 5 to 10%. I have a
pack of (25) T125s in our Solectria with 12,000 miles and they are holding
their own. Of course watering is critical and I think using the bypass
diodes saves on the pack when a lazy battery decides to get hot and turn
into a resistor. AGMs require very close monitoring - tempwise.
Back in the 90s in the Electric 500 races several teams tried the NiMHs,
one day during practice, we saw a good size mushroom cloud out on the
track. After the excitement, I talked to the driver (Billy Roe) and he
told me that he was driving fairly hard and he started to hear what he
thought was sheet metal scraping on the pavement - after a few seconds he
smelled smoke. He stopped the car as fast as possible, unbuckled, exited
and sprinted about 50 feet, when he turned around the car was completely
in flames, every battery contributed to the fire - thus the mushroom. I
think it was an APS car (1million$). Of course it was one of the first
NiMH performance cars, at the time they thought it was an internal arc in
one battery.
As far as controllers, the more air the better, even with water cooled -
eventually you are pumping the heat into the ambient air. We had a few
tricks to cool motors and controllers in endurance competitions.
Jimmy
http://dm3electrics.com/
> From: mike phillips <[EMAIL PROTECTED]>
> Subject: hot climate performance??
> To: ev@listproc.sjsu.edu
>
> I hope this isn't such an elementary question it's beneath people to
> answer,
> but what happens to the performance, range, life, etc of an EV when
> operated
> in Phoenix, Arizona conditions? (temps from 110-120 fahrenheit 4
> months
> out of every year)
>
> Thanks,
>
> MP
>
--- End Message ---
--- Begin Message ---
FOR IMMEDIATE RELEASE:
CONTACT:
Roderick Wilde
Marketing Director
National Electric Drag Racing Association (NEDRA)
Phone: 360-385-7082
Fax: 360-582-1272
[EMAIL PROTECTED]
www.nedra.com
NEDRA to attend RPM Show at Indy.
Indianapolis, Indiana, August 30th through September 1st The National
Electric Drag Racing Association (NEDRA) has been invited to the first ever
RPM Trade Show http://www.aera.org/rpm/attend/index.html to be held at The
Indiana Convention Center sponsored by the Automotive Engine Rebuilders
Association (AERA). They will have a booth along with the well established
National Electric Hot Rod Association (NHRA) and the relatively new Diesel
Hot Rod Association (DHRA). Keynote Speakers will include Shirley Muldowney,
four-time World Champion Top Fuel Driver and Don Schumacher, owner of the
U.S. Army Top Fuel dragster. There will be a roundtable discussion including
John Force, Don Prudhomme, Hillary Will and Cory McClenathan. This event is
being held in conjunction with The Mac Tools US Nationals,
http://www.nhra.com/apcm/templates/preview.asp?articleid=2442&zoneid=90&navsource=18
In addition there will be an E85 ethanol performance competition. NEDRA is
looking forward to presenting world class electric drag racing to the
public. "Plasma Boy"John Wayland's famous Datsun drag car "White Zombie"
will be on display at the NEDRA booth.
ABOUT NEDRA - NEDRA, The National Electric Drag Racing Association is an
educational organization that exists to increase public awareness of
electric vehicle (EV) performance and to encourage through competition,
advances in electric vehicle technology. NEDRA achieves this by organizing
and sanctioning safe, silent and exciting electric vehicle drag racing
events.
-END-
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.394 / Virus Database: 268.9.9/382 - Release Date: 7/4/2006
--- End Message ---
