EV Digest 5399
Topics covered in this issue include:
1) Re: Off-the-shelf LED bar graph voltmeters available? (was: Off-the-shelf
by "Mike Phillips" <[EMAIL PROTECTED]>
2) LCD bar graph monitor (Re: Off-the-shelf LED bar graph voltmeters
available?)
by "Mike Phillips" <[EMAIL PROTECTED]>
3) Re: Low battery voltage limit and signage
by Jeff Shanab <[EMAIL PROTECTED]>
4) Precharge alternatives
by Jeff Shanab <[EMAIL PROTECTED]>
5) Re: Thin wires as fuses? (was: Battery connections assistance sought)
by Lee Hart <[EMAIL PROTECTED]>
6) Potbox and contractor
by "Michaela Merz" <[EMAIL PROTECTED]>
7) Re: Precharge alternatives
by "Chris Brune" <[EMAIL PROTECTED]>
8) Re: Earth Day Adventures with Batteries
by "Philippe Borges" <[EMAIL PROTECTED]>
9) Re: Precharge alternatives
by Lee Hart <[EMAIL PROTECTED]>
10) Re: 156v VW Bus with 156kZilla
by Lee Hart <[EMAIL PROTECTED]>
11) Re: New Panasonic car runs off two AA batteries
by "Ryan Stotts" <[EMAIL PROTECTED]>
12) Re: Potbox and contractor
by Lee Hart <[EMAIL PROTECTED]>
13) White Zombie Update...360 Volts...More HP!
by John Wayland <[EMAIL PROTECTED]>
14) Re: Thin wires as fuses? (was: Battery connections assistance sought)
by "Roland Wiench" <[EMAIL PROTECTED]>
15) Re: AC vs DC; Newbie Question
by Victor Tikhonov <[EMAIL PROTECTED]>
16) Going to the Tour de Sol? Save $2!
by M Bianchi <[EMAIL PROTECTED]>
17) Re: Precharge alternatives
by Neon John <[EMAIL PROTECTED]>
18) Re: Bucking in first gear
by "Rich Rudman" <[EMAIL PROTECTED]>
19) Re: Potbox and contractor
by Neon John <[EMAIL PROTECTED]>
20) Re: Monster Garage
by "Rich Rudman" <[EMAIL PROTECTED]>
--- Begin Message ---
I just remembered another reason I rejected the bar graph solution. In
order to limit the current going into the cabin, resisors had to be
used from each battery. But enough current still had to be passed to
power the circuit and the led's. I recall that the current was high
enough that with all of the batterys leads coming into the cabin, that
meant that full pack voltage was inside the truck, between the 1st
batt and the last batt in the string. Granted, at a reduced current
level because of the resistors, but still too high to be safe.
A better method would be to use something similat to the PS8602 opto,
supply 5v from the vehicle, then have the bar graphs read the return
voltage off of the opto output. That supposes the opto has enough
current to drive the bar graph. The idea is to keep pack voltage out
of the cabin of the vehicle.
Mike
--- In [EMAIL PROTECTED], Mark Freidberg <[EMAIL PROTECTED]> wrote:
>
> James Massey <[EMAIL PROTECTED]> wrote:
>
> Plenty of places have these available in kit form, just a
no-brainer shove all the components into the PCB and practice your
soldering skills.
>
> What is an example of one?
>
>
>
> If you have up to 15 batteries
http://www.jstraubel.com/batbox/monitor.htm
> has a monitor available, although I know no more about it than the
web site shows.
>
>
> I had sent an inquiry a while back to JB Straubel's email listed
on that website, no reply yet. Also Otmar had posted that JB is very
busy, so this may be a dead end.
>
> From posts a while back, TIm Wong and Gordon Stallings have
similar designs--don't know if they'd want to build one. In an ideal
world, I'd just buy a plug and play solution similar to one of these.
>
> An alternative may be to just use one 'tiny' voltmeter per battery
and mount the 12 voltmeters on a panel in the dash area. If each
voltmeter is a 10 segment LED bar graph display, that might work
reasonably well.
>
>
> Mark
>
>
>
>
>
> ---------------------------------
> Blab-away for as little as 1¢/min. Make PC-to-Phone Calls using
Yahoo! Messenger with Voice.
>
--- End Message ---
--- Begin Message ---
I don't know how this would work, but I have the schematics, board
layout and software from Gordon's design. Although it is for my
personal education, maybe Gordon would agree to letting us build some
number of sets of his design. I think any designer worrys about
someone ripping off his hard work. I know I would.
I need to modify his design to cover the 26 batterys in my truck. His
covers 13 right now.
The cost is about $500/set. A different lcd would have to be found as
his original one is not available.
Tim Wong is far more hesitant to cough up his hard work. But has been
answering my design questions.
Mike
--- In [EMAIL PROTECTED], Mark Freidberg <[EMAIL PROTECTED]> wrote:
>
> James Massey <[EMAIL PROTECTED]> wrote:
>
> Plenty of places have these available in kit form, just a
no-brainer shove all the components into the PCB and practice your
soldering skills.
>
> What is an example of one?
>
>
>
> If you have up to 15 batteries
http://www.jstraubel.com/batbox/monitor.htm
> has a monitor available, although I know no more about it than the
web site shows.
>
>
> I had sent an inquiry a while back to JB Straubel's email listed
on that website, no reply yet. Also Otmar had posted that JB is very
busy, so this may be a dead end.
>
> From posts a while back, TIm Wong and Gordon Stallings have
similar designs--don't know if they'd want to build one. In an ideal
world, I'd just buy a plug and play solution similar to one of these.
>
> An alternative may be to just use one 'tiny' voltmeter per battery
and mount the 12 voltmeters on a panel in the dash area. If each
voltmeter is a 10 segment LED bar graph display, that might work
reasonably well.
>
>
> Mark
>
>
>
>
>
> ---------------------------------
> Blab-away for as little as 1¢/min. Make PC-to-Phone Calls using
Yahoo! Messenger with Voice.
>
--- End Message ---
--- Begin Message ---
>The rear ride height should not change the toe on the front.
Maybe in a perfect world, but it changes the front ride height(do to weight
transfer) and the angle of the suspension. Like you mentioned The toe,caster
and camber are inter-related. Different suspensions change different amounts
but this is something all racers know, it is why we do a bump steer test on our
cars and make sure to get the pivot points of the steering system co-incide
with the pivot points of the lower(in this case) arm.
The odd part was the how fast it wore off. Under 1000 miles. I have driven my
truck after an autocross for thousands of miles with drastic, I mean visible
from 20 feet away (3 degrees negative camber, slight toe out) settings and the
tires only wore a little. I am suggesting and pointing out that maybe it is the
heavier weight and maybe it is the old rubber, but this was really fast wear
for the slight excessive toe in.
>You can set the toe anywhere you want and the rear height should not change
>it significantly.
Ok, maybe that is it. We may need to re-define significantly for the weight of
an EV.
>The rear ride height affects the caster therefore causing stability problems
>at speed and steering centering problems as all speeds.
Very true. The steering centering problem places the pivot points in the wrong
spot adding toe errors as the wheel moves up and down over bumps. This bump
steer combined with the different wheel rates from the different loading is
what gives you the instability. When it rained I noticed it more,
>Always set your toe within 1/8 inch of zero to prevent tearing up your tires
>so quickly.
Does anyone know how much a person would change this if they went to solid or
stiffer bushings? I know you never want the toe to go neutral or positive
during braking(unstable) but how much of this 1/8 inch is for the bushing
deflection? (really this is per car thing, track, chassis stiffness, suspension
stiffness and tire offset, all come into play)
>Three years is not really old for tires unless they are race tires.
Well, 3 years of sitting behind a building that I know of. I am gonna disagree
with you here, As a driver I can tell the difference, Maybe that is a byproduct
of living in the central valley, lots of heat and ozone.
Addendum
If you are wondering about why such drastic alignment on the autocrossing
mitsubishi PU, it was established on a skid pad at 11 degree steering angle to
yield the optimum tire patch(measured with a pyrometer) and the higest lateral
G's of 1.2 (no shit!, measured with a G-anylist). It was becasue it was lowered
in a way that kept it in the rules and the method of lowering was short stiff
springs (no drop spindles avail at the time). This put the suspension in a
position where small travels made large alignment changes, and is NOT
reccommended. I learned the hard way that using shortened springs or cut
springs is really a bad way to go, especially on a PU. Cut springs actually
would have bee better than Suspension Techniqes lowering springs as the
increased stiffness made it skip like a stone on rough tracks.(Ah, the
ignorance of youth) The slight toe out gave stability during hard braking and
helped the turn in. 4 turns lock to lock without power steering in an
autocross, LOL.
Bump steer test
remove springs and reassemble mount a plate and 4 dial indicators to it
jack the car up and down thru it's suspension travel and record the changes in
the dial indicators per 1/2 inch of ride height
Repeat at 11 degrees steering each way for a fuller picture of how your
alignment changes during action.
I will agree that usually this is done without reguards to the rear ride
height, it is left at the neutral position. but when we are talking a 2" sag in
back, it is an issue.
--- End Message ---
--- Begin Message ---
I just had a problem with the precharge taking embarrasingly long, now
it takes less than 1 second of turning the key. Can I ask you how much
time yours takes (I am really sure I am the most impatient person on
this list)
What about tieing the precharge to the dome light. close the door and
walk away from the car and it goes to sleep, open the door and by the
time you are in the seat, she is ready to go.
--- End Message ---
--- Begin Message ---
Mark Freidberg wrote:
> ready to install some batts for my Geo... the plan is to place a
> barrier strip along the top edge of the main battery box and connect
> voltage monitoring wires to it from each battery.
I did this on my first Balancer. The wire from each battery had a ring
terminal on the end, which attached to screw terminals on the Balancer's
relay board. The fuse was on the relay board.
I discovered (the hard way) that when you take one of these wires off,
you have a bare ring terminal and an unfused wire to a battery. Drop
that wire, and ZAP! it will land where it can do the most damage!
So I put 0.250" male quick connects on the screw terminals instead, and
crimped insulated female quick connects onto each wire. Makes nasty
shorts much less likely!
> Instead of fumbling with fuses, fuse holders, and their connections,
> could I just use a thin wire length between the positive terminal of
> each battery and the barrier strip? Thin wires that would melt and
> open the circuit in case of a short without catching fire?
Yes, this can work. But the melting point of copper is well above the
ignition temperature of many plastics. Make SURE that fusing the wire
won't set the plastic on fire first!
The worst case is not a dead short, which would melt the wire in a
fraction of a second. It's an overcurrent condition, where the wire gets
very hot for many seconds before finally melting.
You can use wire with a lower melting point. I've see a piece of solder
used. It can be placed in a piece of plastic sleeving.
It's easier and safer to use a real fuse; they've done the testing for
you.
> In addition to just monitoring voltages, it would be nice to be able
> to charge an individual battery if necessary with say 2 amps current.
> Is this doable with the thin wire scheme?
Yes.
--
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 ---
Hello:
A few people on the list suggested to wire the main contractor to the
potbox in order to disconnect the controller once one lifts the foot of
the accelarator (at least this is how I understood it).
First question: Did I understand the concept right?
Second question: I have a Raptor 1200 controller and it usually takes
about 1 or 2 seconds to come up to 'ready' mode. That would prohibit the
idea of doing it that way because in some circumstances, 2 seconds may
just a long time.
Thanks for the answers.
Michaela
--- End Message ---
--- Begin Message ---
Hi John,
First, I really enjoy your posts. You're breadth of technical knowledge is
amazing.
I think you hit the nail on the head with the concern you listed below. We
both know that if you don't have enough capacitance at the controller and
the controller is mounted far from the batteries you will get ringing on the
input line. This will result in a significant loss of power. However, when
you have a say 450A buck converter the worst case input ripple is 50% of
this, or 225A RMS. Well I haven't seen (in the EV market) a contoller yet
that actually has front end capacitors rated for this ripple. It has been
discussed here before that the capacitors should have a ripple current rated
for about 1/20th the output current rating (assuming electrolytics are
used). And if you have this much ripple rating you have way more
capacitance than is necessary.
But depending on how the vehicle is wired I wouldn't be surprised if some of
this input ripple current gets passed back to the batteries. So the stress
on the caps would be reduced some what. Adding a series inductor would
essentially eliminate any ripple current getting back to the batteries.
It would be interesting to measure the ripple going to the batteries before
and after adding the inductance.
Regards,
Chris Brune
----- Original Message -----
From: "Neon John" <[EMAIL PROTECTED]>
> I'm just thinking out loud here before I go out tomorrow and do some
> testing. Has anyone else used this approach and if so, any gotchas?
>
> One potential gotcha I can think of has to do with ripple current back
> to the battery from the PCM action. For a controller with little or
> no input filtering, inductance in the battery lead could result in
> unstable operation or loss of power. At this point I'm assuming that
> any controller with enough input capacity to need worry about inrush
> has enough to limit or eliminate input ripple. True? False?
--- End Message ---
--- Begin Message ---
web link:
it work in both ways ;^)
This ones are 1 or 2 years old laptop cells, impossible to know cell
manufacturer, indicated code is unknown:
B
HHAFJT4
004799
once cycled, they are still giving full capacity
Price is free :^)
cordialement,
Philippe
Et si le pot d'échappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les véhicules électriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "Mike Phillips" <[EMAIL PROTECTED]>
To: "Philippe Borges" <ev@listproc.sjsu.edu>
Sent: Sunday, April 23, 2006 4:12 PM
Subject: Re: Earth Day Adventures with Batteries
> Philippe,
>
> Glad to see you testing these cells. Very educational for me as I'm
> looking into an alternative to lead acid. What part number are they
> and how much did you pay for them?
>
> Your links have the slashes going the wrong way. Try these.
>
> http://vehiculeselectriques.free.fr/images/18650-2200mah.jpg
> http://vehiculeselectriques.free.fr/images/18650piercedtest.jpg
> http://vehiculeselectriques.free.fr/images/18650testAll.jpg
>
> --- In [EMAIL PROTECTED], "Philippe Borges" <[EMAIL PROTECTED]> wrote:
> >
> > Hi,
> >
> > I made similar test as i'm working on similar project :^)
> >
> > Some 2200mah cells i have:
> > http://vehiculeselectriques.free.fr\images\18650-2200mah.jpg
> >
> > pierced twice no spectacular failure:
> > http://vehiculeselectriques.free.fr\images\18650piercedtest.jpg
> >
> > 30V overcharge: nothing happened
> >
> > short circuit to death: nothing happened
> >
> > crushed: nothing happened
> >
> > few tested cells(all burnt marks are from using a torch not from a
> failure):
> > http://vehiculeselectriques.free.fr\images\18650testAll.jpg
> >
> > i made also few videos and safety results are impressive: the only
> way to
> > obtain a visible cell failure is to ignite them hard and even this
> way it
> > only open safety event and let smoke goes out during 10 seconds
> that's all !
> >
> > Next step is assembly, i choose welding.
> >
> > cordialement,
> > Philippe
> >
> > Et si le pot d'échappement sortait au centre du volant ?
> > quel carburant choisiriez-vous ?
> > http://vehiculeselectriques.free.fr
> > Forum de discussion sur les véhicules électriques
> > http://vehiculeselectriques.free.fr/Forum/index.php
> >
> >
> > ----- Original Message -----
> > From: "Arthur W. Matteson" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Sunday, April 23, 2006 10:35 AM
> > Subject: Earth Day Adventures with Batteries
> >
> >
> > > Hi all,
> > >
> > > A belated Happy Earth Day. Despite my busy schedule in graduate
> school
> > > here at Michigan State University, I've been tinkering with some
> > > lithium-ion cells. I am the new proud owner of two "LG Chem." 18650s
> > > from All-Battery.com:
> > >
> > > http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=471
> > >
> > > In addition, I had taken apart a broken Dell laptop battery and found
> > > three good cell pairs, as well as one pair with no voltage at all.
> One
> > > of the four paralleled groups was charged up fully, and exhibited
> about
> > > 60 milliohms of series resistance together or 120 milliohms per
> battery
> > > (also 18650s). Loads of up to 8A were attempted; the batteries are
> > > about 15 deg-C/W case-to-ambient and took about ten minutes to plateau
> > > in temperature. A 0.5W dissipation (a 2A load) is reasonable for
> cool,
> > > continuous operation. Not bad for older/aged 2230mAh units;
> almost 1C.
> > >
> > > I wish to build something with lithium-ion cells...I had in mind a
> > > small, efficient go-kart with a rewound 3/4HP induction motor. This
> > > would be to lightly test a prototype 120V/1000A induction
> controller for
> > > the Renault. (I decided to take Rich's advice and discard my power
> > > supply idea for cost purposes, and just make a simple three-phase
> > > inverter.) Anyway, I could use (30) groups of six paralleled cells to
> > > make a pretty decent pack. For this purpose I had these in mind,
> > > because of their low impedance and cost:
> > >
> > > http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=542
> > >
> > > So I therefore decided to design a battery management system for the
> > > newly bought cells. At first I wanted to go digital, but didn't
> have an
> > > IC lying around with A/D converters. Instead, I settled on a set of
> > > analog hysteresis comparators with a gate driver IC for each cell.
> The
> > > battery would pretend it's shorted when the voltage becomes too
> high or
> > > too low - this is done by connecting the gate driver bus to the cell,
> > > and wiring the pack to its output pin(s). I used TI's UCC37322 9A
> gate
> > > driver for this purpose, as well as half of a TLC2254 quad op-amp.
> > > There is a 20mV hysteresis around 4.2V for turning off, and a 0.2V
> > > hysteresis around 2.8V for turning off - in between will always be on.
> > > The 18650 cells were put in a modified dual-D-cell holder, as seen in
> > > the pictures below. The circuit outputs were wired in series for 7.4V
> > > nominal. Small light bulbs were paralleled for future load testing.
> > >
> > > http://www.egr.msu.edu/~mattes12/bat1.jpg
> > > http://www.egr.msu.edu/~mattes12/bat2.jpg
> > >
> > > As of right now, the green LEDs are flickering because the
> end-of-charge
> > > has been reached. When the cell voltage gets to be above 4.20V, the
> > > light goes off. When it sinks below 4.18V, the light comes back
> on. No
> > > load testing has been done yet. When they came, the batteries
> were both
> > > 3.82V, but exhibited up to 0.2V of difference when being charged. It
> > > seems that approximately the same number of coulombs have been put
> into
> > > each, though - so we'll see what happens later on.
> > >
> > > The batteries are in general impressive. The older cells held a
> charge
> > > very well, despite repetitive 6-8A drains per pair. For their size,
> > > they take forever to recharge - a lot of energy is stored in those
> tiny
> > > cylinders. They seem to be fairly cooperative and consistent. For
> > > someone who is paranoid of gassing, this chemistry is a relief. They
> > > don't seem to be particularly dangerous; I even started to open up one
> > > of the dead ones. I definitely think they are the future.
> > >
> > > But I wonder, how well would it work to parallel six of these? If the
> > > finishing current was a little lower (charging drawn out longer),
> might
> > > this ensure better sharing between them? Again, Dell paralleled
> two and
> > > had four of those groups in series. Has anyone tried similar
> > > experiments to this, or run tests on paralleled cells? Does one
> really
> > > need more than just a simple voltage limiting circuit like this?
> > >
> > > Here is a reference I used:
> > >
> > > http://www.hardingenergy.com/pdfs/LiIon.pdf
> > >
> > > The "Battery University" was also helpful in many situations.
> > >
> > >
> > > Arthur Matteson - East Lansing, MI
> > > 1980 Renault LeCar, "Little Homebrew AC"
> > > http://mywebpages.comcast.net/awmatt
> > >
> >
>
>
>
>
--- End Message ---
--- Begin Message ---
Neon John wrote:
> I'm unhappy with the current practice and techniques of precharging
> the controller caps.
I'm using a 130v 75w light bulb as my precharge resistor. It precharges
in a fraction of a second; far faster than the recommended 750 ohm
resistor. Yet it still limits the current to a reasonable value.
The Zilla precharger uses a MOSFET to switch in a string of computer
power supply inrush limiters. Needs a little PC board with a dozen or so
parts.
How about a really odd solution? Use a vacuum tube rectifier, like a
12X4. The isolated 12v filament is powered by your key switch. The
cathode and anodes connect across your main contactor, to controller B+
and pack+ respectively. To precharge, power the filament. A diode with
some series resistance appears between anode and cathode, and the
controller precharges.
> One of the standard industrial methods of limiting inrush or fault
> current is a high current air core inductor in series with the load.
> The inductance is high enough, however, to limit inrush or fault
> current to a design value.
You could do this, but it's physically large. As you say, it would also
shift ripple current from the batteries to the capacitors.
The inductor would work better if the controller used low-ESR film or
oiled paper capacitors. The same ESR would use 1/10th to 1/100th of the
capacitance, and so require far less inrush suppression.
The main contactor could also be placed between the capacitors and the
controller itself. This has the consequence of murdering the
semiconductors if that contactor ever opened under load.
> Physical size won't be a problem since it'll only take a few (hundred)
> microhenerys to limit the inrush to a few hundred amps.
Be aware that a few hundred microhenries at a few hundred amps is a BIG
inductor!
> Any idea how much input capacitance in, say, an Alltrax 7845?
I don't know about that one, but other common controllers use 10,000uF
or more.
--
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 ---
Lawrence Rhodes wrote:
> I have a client that wants to do a family vehicle and I recommended
> a VW bus. I think it will handle 156volts of flooded(26) with a 156v
> Zilla, Iota DC/DC, Rudman PFC20, & a 9" ADC or similar.
Which one? The old 60's Microbus, the Vanagon, or current Eurovan?
There were many microbus conversions in the 60's and 70's. They are
small and light, and carry a lot of weight for their size; but nowdays
are pretty scarce and old, and had some serious safety problems.
The Vanagons were nicer vehicles, but also bigger and heavier and so
couldn't carry as many batteries.
The Eurovans are very nice, but *really* heavy -- mine is 4300 lbs with
a 5800 lbs GVWR. It would be an expensive conversion.
With any van, aerodynamics are poor. It won't be practical to get good
range at high speeds.
Something I've thought about is making my Eurovan into a hybrid. The
inside ends of the rear axles are exposed, with places for the yokes of
universal joints for a rear differential (for the 4WD option). I've
thought of adding the rear differential, and driving it with an electric
motor. Put a smallish battery pack under the floor. Drive it around town
as an EV, with the ICE off or just idling to provide power steering,
brakes, heat, air conditioning, etc. Use the ICE normally for long
trips.
--
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 ---
Here's a pic of a AA next to a disasembled laptop battery for size comparison:
http://img48.imageshack.us/img48/3122/bat3kr.jpg
--- End Message ---
--- Begin Message ---
Michaela Merz wrote:
> ...wire the main contactor to the potbox [switch] in order to
> disconnect the controller once one lifts the foot off the accelarator
> I have a Raptor 1200 controller and it usually takes about 1 or 2
> seconds to come up to 'ready' mode. That would prohibit the idea of
> doing it that way because in some circumstances, 2 seconds may just
> a long time.
You're missing the precharge resistor across the main contactor.
When the key is off, both the main contactor and a smaller one for the
precharge resistor are open. Thus the controller B+ is not connected to
pack+.
When you turn on the key, a small relay immediately connects the
precharge resistor across the main contactor. The resistor precharges
the controller in a second or so.
When you step on the accellerator, its switch powers the main contactor.
It closes, and now you can drive.
Every time you release the accellerator, its switch opens and turns off
the main contactor. But the controller stays precharged by the resistor,
so the response is instantaneous when you step on the accellerator
again.
--
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 ---
Hello to All,
I got an interesting phone call Friday night from one of our local EVers
here in Portland, Jay Donaway. He was wondering if we were going racing
with White Zombie at PIR. You see, Oregon's weather in the Spring can be
anything, going from foreboding black clouds and hail, to sunshine, then
wind, then rain....this is during the course of one day! This is how
Spring has been so far, that is, up until this week. We've had a few
days where the temps rose from cool high forties to low fifties, to high
60's with one day even touching 70! Then yesterday, we reverted back and
the day started off cold and rainy but then, it cleared up dramatically
and the day turned into early evening with the temps in the 60's. The
forecast is calling for glorious mid 70's both Saturday and
Sunday....drag racing weather is finally here! In fact, the 7 day
outlook has no rain in sight and high 60's every day.
With this backdrop, I told Jay 'no' to going racing. What, perfect drag
racing weather after waiting all Winter, and team Plasma Boy is absent
from the race track? Here's the deal. We've made a commitment to show up
at the High Voltage Nationals in Joliet, Illinois, just three weeks from
now, an we'll be there as planned. It would be foolish and selfish, to
go racing, break the car, then be a no-show at this first-ever race
where lots of people are counting on us. Instead, the car is being
'pumped up' and readied for its debut at the Route 66 track more than
half way across the great USA.
Each weekend has been packed with EV building activity, much of it going
into Baby Blue, the 276V Datsun minitruck I wrote about last week. Marko
and I worked on Baby Blue again yesterday, Saturday. Today, Sunday, is
White Zombie time, and as I type this, Tim Brehm is on his way here. The
new pack of Aerobatteries are being installed today, but this time
there'll be 30 of them, not the regular 29. Though the Zilla tops out at
348V nominal, it's the 'nominal' part we're dancing around. Assuming a
pack at 360V can rise to 450V under charge with each battery peaking at
15V, to keep in the safe operating area of 'under 450V', the max
nominal pack recommended is 29 batteries at 348V. We're pushing things
though and are going with 30 batteries and will do 'charging things' in
a certain way to stay out of trouble. I do not recommend that others try
this with their street Zilla powered EVs and I certainly don't want to
cause Otmar any grief over this, but hey, this is racing and if we can
push something a bit to go quicker and faster, than so be it. I've also
got the master's OK on my 360V plan, so it's not as if he doesn't know
what I'm up to :-)
Other changes to the car include the high rpm field weakening circuit
that's nearly completed, and the still-to-be-done gear ratio change to a
taller 4:10 over the present 4:57 ratio. Hopefully, our killer hole shot
won't go away with all that low end torque we have on tap, and the
taller gear set will keep the car in series mode longer for an even
quicker 1/8 mile time than the present best 1/8th mile of 7.59 seconds.
In the parallel mode with a slightly higher voltage pack behind the
controller and the taller gears to pull against, the motor torque will
stay stout longer as the controller is held in current limit longer. Top
end acceleration should be very strong. Near the end of the run, Tim
will hit 'the button' and bring on field weakening to keep the Siamese 8
humping all the way up to 7000 rpm and hopefully, terminal speeds
exceeding 110 mph through the traps as we bust into the 11's.
Will Jim's mighty Siamese 8 hold up to this? Will the Hawker
Aerobatteries stay together? Will the Zilla keep its smoke in (stupid
question)? Will Marko's minitruck not break down? Will its generator
keep running? Will the charger hold up under continuous high currents
across the country? We'll all find out in less than 3 weeks from now at
Route 66!
See Ya.......John Wayland
Plasma Boy Racing 'We blow things up, so you don't have to'
http://www.plasmaboyracing.com
--- End Message ---
--- Begin Message ---
How about using a fuse wire. You can get the fuse wire in No. AWG 18 to No.
AWG 8 at a auto parts store. The specs. on the package of wire will state
the running amperage and short circuit ampere rating of the fuse wire.
This wire is rated for 12 volt circuits of which your tapped off each
battery is a 12 volt circuit. I have run this type of wire off 180 volts
circuits, and nothing blew up yet while I had it in the EV for 15 years. I
change all these type of fuse wire with industrial fuse holders with blown
fuse indicators which are track mounted in rolls of terminal blocks.
The insulation is a little heaver, that contains the the melting of the wire
inside the insulation. You cannot tell if the fuse wire blew by just looking
at it.
You only need to install about a 4 to 6 inch length of this fuse wire which
would connect right at the battery. You may notice this type of wire is use
as a tapped off of a 12 volt accessory batteries. There is about a 6 inch
long fuse wire which is splice to a regular wire.
To test to see if this fuse blown with out a meter, is just pull on the two
ends of the wire, if it stretches like a rubber band, than the wire is blown
apart inside the insulation.
Roland
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Sunday, April 23, 2006 9:41 AM
Subject: Re: Thin wires as fuses? (was: Battery connections assistance
sought)
> Mark Freidberg wrote:
> > ready to install some batts for my Geo... the plan is to place a
> > barrier strip along the top edge of the main battery box and connect
> > voltage monitoring wires to it from each battery.
>
> I did this on my first Balancer. The wire from each battery had a ring
> terminal on the end, which attached to screw terminals on the Balancer's
> relay board. The fuse was on the relay board.
>
> I discovered (the hard way) that when you take one of these wires off,
> you have a bare ring terminal and an unfused wire to a battery. Drop
> that wire, and ZAP! it will land where it can do the most damage!
>
> So I put 0.250" male quick connects on the screw terminals instead, and
> crimped insulated female quick connects onto each wire. Makes nasty
> shorts much less likely!
>
> > Instead of fumbling with fuses, fuse holders, and their connections,
> > could I just use a thin wire length between the positive terminal of
> > each battery and the barrier strip? Thin wires that would melt and
> > open the circuit in case of a short without catching fire?
>
> Yes, this can work. But the melting point of copper is well above the
> ignition temperature of many plastics. Make SURE that fusing the wire
> won't set the plastic on fire first!
>
> The worst case is not a dead short, which would melt the wire in a
> fraction of a second. It's an overcurrent condition, where the wire gets
> very hot for many seconds before finally melting.
>
> You can use wire with a lower melting point. I've see a piece of solder
> used. It can be placed in a piece of plastic sleeving.
>
> It's easier and safer to use a real fuse; they've done the testing for
> you.
>
> > In addition to just monitoring voltages, it would be nice to be able
> > to charge an individual battery if necessary with say 2 amps current.
> > Is this doable with the thin wire scheme?
>
> Yes.
> --
> 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 ---
Thanks Peter, I understand, and I didn't try to prove you wrong.
I just wanted to make sure newbies understand that too low voltage
for an AC system is not a fundamental limitation: they can be built
for any arbitrary voltage, 12VDC one you wish.
But the ones normally built and used in EVs indeed will have
very poor performance at low voltage limit and you're right -
while will push the vehicle, not worth the money at all.
One *only* takes real advantage of AC system if the voltage
is at least half way between limits. The higher - the better
[utilization of money].
Victor
Peter VanDerWal wrote:
Hi Victor,
I didn't mean to say that it wasn't possible, just that it wasn't worthwhile.
You've stated it better than I did. My brevity has risen up and bitten me
again.
Anyway, we agree that it's probably not worth it, especially since I
suspect the reason for going with low voltage was to save money.
--- End Message ---
--- Begin Message ---
The 2006 Tour de Sol is two weeks away - and there is much excitement in the
air! The quality of entrants and exhibitors is also terrific. Three plug-in
hybrids, four hydrogen vehicles, two advanced battery electric vehicles, two
modified Honda Insights, and a team from India are just some of the highlights!
www.TourDeSol.org
If you are going to the Tour de Sol this year, be sure to download the $2 off
coupon found at
http://www.AutoAuditorium.com/Tour_de_Sol_2DollarsOff.pdf
(Foveal Systems / AutoAuditorium System is a sponsor.)
Want to help advertise? Download the poster at
http://www.AutoAuditorium.com/Tour_de_Sol_poster.pdf
See you there!
--
Mike Bianchi
--- End Message ---
--- Begin Message ---
On Sun, 23 Apr 2006 08:37:48 -0700, Jeff Shanab
<[EMAIL PROTECTED]> wrote:
>I just had a problem with the precharge taking embarrasingly long, now
>it takes less than 1 second of turning the key. Can I ask you how much
>time yours takes (I am really sure I am the most impatient person on
>this list)
To tell the truth, I'm not pre-charging at all right now. And I sorta
cringe every time I hit the switch and hear the snap from the
contactor. As for impatience, I have the patience of Job when there's
a good reason but I'll probably run neck and neck with you when there
isn't.
>
>What about tieing the precharge to the dome light. close the door and
>walk away from the car and it goes to sleep, open the door and by the
>time you are in the seat, she is ready to go.
>
This is a CitiCar so there isn't any dome light :-) There are any
number of things I could do to shorten the charger time. For example,
the bucket seats I just scavenged from the junque yard have switches
in them, for the seat belt buzzer, I guess. I could hook that up so
that when I sat down the pre-charge would activate.
But I don't want to. Pre-charging is inelegant to me and it involves
more moving parts and things to go wrong. I like the simple elegance
of an inductor that has no moving parts and no semiconductors to fail
and yet does the job. I'm going to try it and see how it works. I
just wanted to chat about it a bit to make sure I hadn't overlooked
something important.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
Ot..
The twin 8s had a little bit of a surge issue in first gear. And yes I have
a VERY steady right foot.
I just back fit my Kostov 11 into the Fiero.. and Well not much surging..
Kind like the old days with a T-Rex.
And I just added a 2nd return spring and realigned the Zero point on the
Throttle pot.. Now we got some throttle response.
The twin 8s in parallel, Definatley had a sharper current response. But the
old Kosty can be ... advised to get with the program with more Zilla.
Yea.. I need the tach so I can launch in first... those wheel stands are
really close to Wheel spins.. I want my motor to live...a short while
anyways...
Right now I have 1st an 2nd Gear.. and a head cold so I am not inclined to
go wrenching in the rain today...
Hack hack Snort!
Madman
----- Original Message -----
From: "Otmar" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, April 20, 2006 9:15 PM
Subject: Re: Bucking in first gear
> >I drive around in second and 3rd, sometimes 4th in my 300zx (zilla1k on
> >24 orbitals)
> >
> >Yesterday I decided to check accelertion in first instead of second and
> >it bucked wildly even at part throttle.
> >
> >I was wondering how current limit and voltage limits are handled in the
> >hairball and what was happening.
> >
> >My motor voltage limit is set for 170, my battery amps limit is set for
> >1000 and my low battery voltage limit is set for 240V.
>
> What are you using first gear for! Trying to bow the motor again? :)
> It's very unusual to find benefit from first gear in most DC EV's.
>
> I certainly would not run first at full throttle (especially without
> a speed sensor) unless you really want to rebuild the motor again.
> What's redline, 25 MPH? Spin those tires and you can hit 80 mph in
> under a second.
>
> You'll need a stout throttle return spring if you want to drive in
> first at less than full throttle to avoid foot oscillations. You
> should always have at least two springs anyway. Lot's of torque in
> the motor there that was not there as a gas car. Or you can turn
> motor current below 200 amps and it should be smooth.
>
> Motor voltage cutback is normally smooth and should not be related.
>
> I suspect that what has happened is that your ultra light torque load
> in first has the throttle out of the normal smooth current limit mode
> and running in voltage control (like a Curtis). With high pack
> voltages such as yours voltage control will be very jumpy to hold. It
> should still be smooth at full throttle, so I would check the DAQ to
> insure that you really are holding full throttle (only with a speed
> sensor and rev limit installed). Or better yet, don't use first gear.
>
> I'm not saying that it's not a problem with the Hairball, you never
> know when a bug will show up. The Zilla has always had a reputation
> as a very smooth controller. Of course, I drive in third gear, so if
> a problem was developing along the way I may not have noticed it in
> testing after the initial design verification (which was done in
> first, in a couple of cars). But if it's only in first gear then that
> points toward installation issues.
>
> hth
> --
> -Otmar-
>
> http://www.CafeElectric.com/
> The Zilla factory has moved to Corvallis Oregon.
> Now accepting resumes. Please see:
> http://www.cafeelectric.com/jobs.html
>
--- End Message ---
--- Begin Message ---
On Sun, 23 Apr 2006 10:42:17 -0500 (CDT), "Michaela Merz"
<[EMAIL PROTECTED]> wrote:
>
>Hello:
>
>A few people on the list suggested to wire the main contractor to the
>potbox in order to disconnect the controller once one lifts the foot of
>the accelarator (at least this is how I understood it).
>
>First question: Did I understand the concept right?
Yep. I regard it as un-necessary but that's the idea if you want to.
The (IMO) excessively cautious notion is that if the contactors opens
on every throttle-lift then if the controller fails on, the car still
stops. While true, the odds of a controller failure are low. For
that rare occasion, either include a big red kill button on the dash
or mentally train yourself to hit the switch if the throttle 'sticks',
just like you would in a gas car.
Chugging the contactor every time you lift the throttle puts a lot of
wear and tear on a fairly expensive component. And if the controller
does have an internal bleeder resistor, you'll be thumping the
controller's caps every time you touch the throttle.
I'd rather just train myself to reflexively react to a stuck throttle
by batting the kill switch.
>
>Second question: I have a Raptor 1200 controller and it usually takes
>about 1 or 2 seconds to come up to 'ready' mode. That would prohibit the
>idea of doing it that way because in some circumstances, 2 seconds may
>just a long time.
I don't know the Raptor well enough to say for sure but that's
probably just the pre-charge interval we've been discussing in another
thread. Once the "ready" light is on, try turning the contactor off
and right back on. If the "ready" light comes right back on then it's
simply indicating that pre-charge is complete. The capacitors
internal to the Raptor should hold their charge for a significant
amount of time - minutes - unless there is a bleeder resistor
involved. Even if there is a bleeder, it should hold up for many
seconds.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
Yea Jesse is a Anti host..
neat way of putting it...
We made it run...
I am not sure if that was in the script from the begining..
But we feel we got lucky and Worked our butts off.
At about 5 points they could have hosed us beyond recovery..they didn't...I
expect that having a Megga spnosor involved, kinda made it in his best
interest to let us meet our goals.
Madman
----- Original Message -----
From: "Jorg Brown" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Saturday, April 22, 2006 5:50 PM
Subject: Re: Monster Garage
> On 4/14/06, DM3 <[EMAIL PROTECTED]> wrote:
> >
> >
> > Rich and Shawn,
> > I need to ask, when Jessie says, "stupid electric car" was that part of
> > the script, jessie twisting the knife or just covering his butt if it
> > bombed?
>
>
> In one of the articles I've read about Monster Garage, one of the
producers
> refers to Jessie as the "anti-host" - he literally does all sorts of
things
> the host should never do - often not appearing on any given day of the
> Monster build, casually trashing this or that guest. The first two times
> that Monster Garage hosted all-girl guest teams are good examples of the
> dark side of Jessie - he doesn't help them much and his commentary is all
> about how they're going to fail - which both teams did. (Side note: I
> haven't watched MG much recently, so I don't know if any all-girl teams
have
> ever succeeded)
>
> There's an old saying: all publicity is good publicity. You and I may be
> disappointed about the performance of the electric car they built in a few
> days out of batteries meant for cordless drills... but there are countless
> others who will watch it and think, hey, they made this electric monster
car
> out of drill batteries! And it got 14.5! Sure, it's no supercar but
> 14.5is at least respectable.
>
> As I write this, oil is above $75 per barrel, gas here in CA is above
> $3.00/gallon, and both are continuing to head skyward. Stupid gas cars.
>
--- End Message ---
