EV Digest 3402
Topics covered in this issue include:
1) Re: Why am I not supposed to parallel cells/batteries?
by Lee Hart <[EMAIL PROTECTED]>
2) Re: group orbital buy?
by "bobrice" <[EMAIL PROTECTED]>
3) Re: group orbital buy?
by Seth Murray <[EMAIL PROTECTED]>
4) Engineering opportunity w/ hybrid vehicle design in Detroit
by "Myles Twete" <[EMAIL PROTECTED]>
5) Re: Generator and AC motor -home power mag, #71
by Rod Hower <[EMAIL PROTECTED]>
6) Re: Why am I not supposed to parallel cells/batteries?
by Lee Hart <[EMAIL PROTECTED]>
7) Re: Flaming wreckage...
by Lee Hart <[EMAIL PROTECTED]>
8) Re: battery charge profile
by [EMAIL PROTECTED]
9) Re: Fast charging
by "Tim Clevenger" <[EMAIL PROTECTED]>
10) Re: Fast charging
by Reverend Gadget <[EMAIL PROTECTED]>
11) Re: Flaming wreckage...
by Christopher Zach <[EMAIL PROTECTED]>
12) Re: Fast charging
by Rich Rudman <[EMAIL PROTECTED]>
13) Re: Fast charging
by Reverend Gadget <[EMAIL PROTECTED]>
14) Re: Flaming wreckage...
by Rich Rudman <[EMAIL PROTECTED]>
15) Donor Car Recommendation
by "Don Cameron" <[EMAIL PROTECTED]>
16) Re: Tektronix 475 Scope
by Lee Hart <[EMAIL PROTECTED]>
17) RE: Tektronix 475 Scope
by "Don Cameron" <[EMAIL PROTECTED]>
18) RE: battery charge profile
by "Roger Stockton" <[EMAIL PROTECTED]>
19) Re: battery charge profile
by [EMAIL PROTECTED]
20) Re: Fast charging
by Rich Rudman <[EMAIL PROTECTED]>
21) Re: fun with powerwheels 2...
by "Mark Thomasson" <[EMAIL PROTECTED]>
22) Re: Donor Car Recommendation
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
23) Re: Donor Car Recommendation
by "David Roden" <[EMAIL PROTECTED]>
24) Re: Donor Car Recommendation
by Ben Apollonio <[EMAIL PROTECTED]>
25) 2004 Prius EV Mode Button
by Edward Ang <[EMAIL PROTECTED]>
26) Re: Rewinding a charger transformer - strange turns.
by James Massey <[EMAIL PROTECTED]>
--- Begin Message ---
Justin Southam wrote:
> I thought it might be practical to build large parallel cell modules
> by milling circular recesses into say 1/2" aluminium plate, insert
> the cells into it then place a mirror of the bottom plate on top
> and clamp the plates together using say threaded nylon rod or
> nylon strapping. This would form a building block to build batteries.
I don't think this would work, for a number of reasons. The cells are
not all exactly the same length; there is a +/- tolerance. So clamping
them between flat plates will leave some tight and some loose.
The cells are likely to expand and contract over time and temperature.
Even if they were all tight when you started, they would loosen over
time.
Aluminum is a terrible material for make electrical connections. It
forms an insulating oxide coating almost immediately. It takes enormous
contact pressures to get a good contact with aluminum, far higher than
it would take to crush the cells.
I don't think you want a low-resistance connection between parallel
cells. This would only encourage problems if the cells get out of
balance or go bad.
To make your idea work, I think you would have to use something more
like a flexible thin copper sheet. Perhaps use a plastic grid as tall as
the cells and with holes to position them, lay a sheet of copper over
them, then another plastic grid, etc. Clamp the whole stack with some
kind of spring plate to maintain pressure contact with every cell.
Cooling would be a problem. The center cells would be very hard to cool.
You may need holes punched in the copper sheets to allow axial airflow.
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: Jim Coate <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, March 11, 2004 1:05 PM
Subject: group orbital buy?
> Hey Seth -
> Hey Jim!
> evsource.com has a banner ad from auto supply for Orbitals at $98 plus
> whatever shipping is but I can't imagine more than $10/battery.
>
> Maybe we should get together for a group order as I'm going to be
> looking too? 16(?) for you + 17 for me = 33+ batteries. Then can talk to
> regular suppliers or maybe try John Wayland himself?
> Count me in on prices an's stuff on orbitals.Like how much for a pallot
load. maybe 45?
Bob. another East Coaster heard from
> And I like the Maine version of Motel 6 rates... $33 bux for a night.
> I'm selling enough crap on eBay to more than pay for my contra trip :-)
>
> Come to think of it, you might want to eBay your T-Rex. This is kinda
> rude, but the masses may be less well informed than EVDL members and be
> more willing to buy obsolete products. I think someone sold a aircraft
> generator & contactors VW conversion kit on eBay for serious money. And
> Ryan is giving $200 off Zillas from evsource.com for the month of March.
>
> cya.
> Jim
>
> Seth Murray wrote:
> > I am shooting for performance close to or a little better than stock. I
> > have a 9" WarP, T-Rex 1000 (trying to sell it and get a zilla) and am
> > planning 192V of optimas probably, or orbitals. Here in Maine, not 5
> > miles from my house, I can get optimas for $125 but the best I can do on
> > orbitals is $135 in worcester, MA. My concern with putting 240V in a
> > 240Z (wouldn't that be perfect?) is that the car is built really lightly
> > and I don't want to overload it. Even adding a small block V8 to a Z
> > car (a common 'conversion') adds just under 200 lbs. I think I'll stick
> > with 192 but I think you can probably do 240 in a ZX ok. should be a
> > fun conversion, keep us all up to date and take lots of pictures.
>
>
> _________
> Jim Coate
> 1970's Elec-Trak
> 1992 Chevy S-10 BEV
> 1997 Chevy S-10 NGV
> http://www.eeevee.com
--- End Message ---
--- Begin Message ---
I could be interested but not until closer to the end of this summer...
seth
On Thursday, March 11, 2004, at 01:05 PM, Jim Coate wrote:
Hey Seth -
evsource.com has a banner ad from auto supply for Orbitals at $98 plus
whatever shipping is but I can't imagine more than $10/battery.
Maybe we should get together for a group order as I'm going to be
looking too? 16(?) for you + 17 for me = 33+ batteries. Then can talk
to regular suppliers or maybe try John Wayland himself?
And I like the Maine version of Motel 6 rates... $33 bux for a night.
I'm selling enough crap on eBay to more than pay for my contra trip > :-)
Come to think of it, you might want to eBay your T-Rex. This is kinda
rude, but the masses may be less well informed than EVDL members and
be more willing to buy obsolete products. I think someone sold a
aircraft generator & contactors VW conversion kit on eBay for serious
money. And Ryan is giving $200 off Zillas from evsource.com for the
month of March.
cya.
Jim
Seth Murray wrote:
I am shooting for performance close to or a little better than stock.
I have a 9" WarP, T-Rex 1000 (trying to sell it and get a zilla) and
am planning 192V of optimas probably, or orbitals. Here in Maine,
not 5 miles from my house, I can get optimas for $125 but the best I
can do on orbitals is $135 in worcester, MA. My concern with putting
240V in a 240Z (wouldn't that be perfect?) is that the car is built
really lightly and I don't want to overload it. Even adding a small
block V8 to a Z car (a common 'conversion') adds just under 200 lbs.
I think I'll stick with 192 but I think you can probably do 240 in a
ZX ok. should be a fun conversion, keep us all up to date and take
lots of pictures.
_________
Jim Coate
1970's Elec-Trak
1992 Chevy S-10 BEV
1997 Chevy S-10 NGV
http://www.eeevee.com
--
QUESTION INTERNAL COMBUSTION
'72 Datsun 240Z Conversion
http://users.wpi.edu/~sethm/
--- End Message ---
--- Begin Message ---
Searching for engineering work today turned up this hybrid electric vehicle
design job in Detroit:
http://jobsearch.monster.com/getjob.asp?JobID=21213086
-Myles Twete, Unemployed in Portland
--- End Message ---
--- Begin Message ---
Does anybody on the list have home power
magazine issue number 71, June/July 99
in .PDF format they could email to me?
Thanks,
Rod
--- End Message ---
--- Begin Message ---
Lightning Ryan wrote:
> I brought a "battery" that I assembled out of 1.2-1.4Ah 18650
> cells to the Seattle EVA meeting on tuesday... I have this gut
> feeling that what I've done is potentially very bad for some
> reason. But all I can figure is that if 1 cell "dies" that
> the other 4 which are in parallel with it will discharge into
> the bad call, perhaps lighting it up like a bad fireworks
> display. But I feel that this is an unlikely long shot.
I think the fundamental problem is that nobody knows for sure what might
happen.
With lead-acid, there is a fundamental reason why the voltage is a
function of state of charge. When you parallel cells, they tend to
self-balance at the same state of charge. Also, internal resistance goes
up as state of charge goes down; this tends to shift the load during
discharge to the cells that have the most charge. We have 100+years
experience with paralleling lead-acid, and the dangers and failure modes
are known. Things like if a cell fails shorted, the others in parallel
will boil its electrolyte or melt its interconnections. It's messy, but
the lead and electrolyte won't burn. Or, if one cell gets hot its
voltage goes down, so it sucks current from the others, getting still
hotter, until it runs down the whole parallel stack. In this case you
wind up with a mysteriously dead set of cells. Or, some cells just don't
last as long because they wind up doing more work.
With nicads, there is no fundamental change in voltage with state of
charge. So, nicads in parallel don't self-balance very well. It still
sort-of works, because there is a voltage rise at the end of charge, so
they may re-balance at full charge. There is a fall-off in voltage at
the end, so they may re-balance at full discharge (as each cell goes
dead, it ceases to contribute current). But when people have parallelled
nicads, there have been problems. Small differences in cell temperatures
lead to large differences in state of charge. Since cell voltage can
peak at full charge and then go back down, it gets very hard to tell
when to stop charging. The extremely low resistance of even a dead nicad
can lead to spectacular failures if one shorts.
Nimh have all the same problems as nicads, plus a few new ones. For one,
they can burn! But we basically have a lot less experience in
parallelling them.
> death should be a slow degradation, that eventually shows up
> when one parallel set begins to self discharge more rapidly.
Death *should* be slow, but it could also be dramatic. A cell could
short, either from a maufacturing defect, random failure, or even from
penetration during a car crash.
If a cell shorts, I think it is mandatory to have some kind of fuse to
prevent the rest of the parallelled cells from discharging into it at
high current.
The major new hazard with lithium cells is that they can *burn*! They
have the potential to provide the fuel, oxidizer, and heat source all in
one package, so once they get started, it could be impossible to
extinguish them! Battery manufacturers try to minimize the risk, of
course, but they are testing one isolated cell, not a dense pack of
hundreds of them.
> Would using fuses, or smaller (vaporizeable) wire make it safe?
> They are only there to keep the parallel cells in balance, these
> wires don't carry the load, the series interconnects are much
> larger and this is where the heavy load flows through.
I don't think you can rely on parallelling LiIon cells to make them
self-balance. There is a slight voltage versus state of charge curve,
but the ones from temperature, current, and aging seem to be larger.
Since you need per-cell management anyway, and all the chips on the
market assume single cells (not parallel groups), I tend to think it
would be better not to parallel cells, except with fairly high
resistance parallel wiring.
> It seems to me that this is a much simpler way to keep large
> numbers of small cells in balance, and makes me question my
> preconceptions of how the T-Zero pack might be layed out.
Everyone always looks for the cheap easy solution. Sometimes the
ignorant get lucky. More often, they don't. Some of the most spectacular
failures in engineering have occured because someone figured something
was 'good enough' and 'that won't happen'.
The bottom line is that we don't have enough experience with
parallelling LiIon cells to know all the things that might go wrong. My
fear is that the consequences of a mistake might reach Hindenburg-like
proportions (i.e. such a spectacular failure that it gets national media
attention and sets the EV movement back for decades).
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
David Chapman wrote:
> Bill Griffen was building just such a fuse holder out of Delrin
Delrin would be a bad choice. It melts and it burns. Not good things for
a fuseholder. Most commercial fuseholders (that are UL list and so have
actually been tested) are made of bakelite, phenolic, ceramic,
fiberglass, etc.
Ruch Rudman wrote:
> I have never had a fuse part. I don't think it's a real issue.
They won't for a modest overload (like 4x of rated current). But they
can and do for a major overload (like 10x to 100x rated current)! I've
seen UL movies of fuse tests where they did this, and they are
impressive!
Ever seen the 'exploding wire' trick? Charge up a big capacitor to a
couple hundred volts. Short it thru a small piece of wire. The wire goes
*KABOOM* just like a firecracker. It will also blow holes in things just
like a firecracker. (I do it with a 1000uF capacitor, mercury switch in
series with a few feet of #18 AC line cord, with just one strand
shorting the far end together. Charge up the capacitor to a few hundred
volts, tip it over so the mercury switch shorts, and BANG!)
Now, the fuse link inside a fuse is just such a little wire (you'd be
amazed at how small it is in a high-current fuse). The controller
provides just such a set of high-current capacitors. All you need is a
nice, solid short circuit. What do you think a firecracker going off
inside your fuse would do?
Normally, an excess current just melts the metal fuse link. The molten
metal just drips away from gravity to open the circuit. There will be
some arcing when the gap first opens, and that may vaporize a little
metal, but not much.
At very high currents, the metal melts, but then the liquid metal
continues to carry current. Before gravity can pull it away, the liquid
metal vaporizes. Converting the metal into gas causes a large increase
in pressure inside the fuse. Meanwhile, the arc through the ionized gas
just heats it further. The superheated gas pressure finally blows the
fuse apart.
I've exploded lots of glass 3AG type fuses (the 1.25" x 0.25" diameter
ones); just put an AC rated one in a DC circuit. The ceramic ones are
much tougher, but I've still done it. I've blown the ends off the cheap
phenolic tube fuses used in household wiring too, in my old Datsun with
its golf cart batteries when the contactor controller failed (probably a
10x overload on a 200a fuse).
I now will use only the DC-rated "semiconductor" fuses in my EVs. You
can tell they are built to mightily resist exploding. The Gould "Shawmut
Amptrap" A50P300 I have in my LeCar EV is rated 500vdc, 300amps, 10,000
amps interruting capacity (shouldn't explode at under 10,000 amps). It
has a 1/8" wall thickness fiberglass tube for a body, with 4 1/8" pins
at each end to hold in the massive cast copper endcaps. The fuse element
inside is pure silver, packed in sand. It's mounted on two phenolic
standoffs with 5/16" studs embedded in it, bolted to a 1/8" aluminum
plate. I fugure that ought to do it! :-)
Victor Tikhonov wrote:
> This is a holder for a liquid hose of an ICE, and made from high
> temp withstanding plastic, not polyethylene (or such) thermoplastic.
That clamp only has to survive boiling water; that's not very hot at
all. Try running rated current thru a fuse for a while, and notice how
hot it gets. The Gould A50P300 I use measures 0.0004 ohms. At its rated
current (300a) it is dissipating P = I^2 x R = 36 watts. That's a LOT
for a device only 4" long and 1.5" diameter. Think about how hot a 40w
light bulb gets, and it's about the same size. Another part of the job
for a good heatsink is to dissipate this heat.
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Mark,
In a message dated 3/12/2004 8:53:29 AM Eastern Standard Time, [EMAIL PROTECTED]
writes:
> It is possible that Steve is seeing shortened life on the batteries due to
> the high current draw of twin 400A controls/motors without the benefit of a
> transmission. It would be interesting to know if all Tropica drivers
> experience this same phenomenon. I believe the current draw is above the
> recommended and might be better off with Optima,Orbital or Hawker's for the
> high acceleration requirements.
Perhaps. I try to keep the current down. I have a "highly accurate" guage (bar graph)
to display current. Ten segments at about 40amps each. The current measure is on the
battery side. When I start out, it pegs for a second or so but I try to keep it down.
At 40mph it's just below 80amps and at 60 it's at about 160amps. Most of my driving
has been freeway. There is one interchange on the freeway that has quite a hill but I
don't try and maintain speed.
I'm not sure how many miles the other owners are getting. I believe Scott has the
record for the most miles on a Tropica at about 13k. I know he went through at least 2
packs. I might be second in the mileage catagory at about 6.5k. My first pack was
wiped out when I got the car just from being left alone. The previous owner just let
it sit and discharge.
Steve
--- End Message ---
--- Begin Message ---
Check out the current issue of Homepower. A family there ended up with a
bit
over 53% of their PV setup paid for by the state (between the CA rebates and
the state tax deduction.)
Tim
------------
Date: Thu, 11 Mar 2004 23:08:38 -0800 (PST)
From: Reverend Gadget <[EMAIL PROTECTED]>
Subject: Re: Fast charging
To: [EMAIL PROTECTED]
I'd love to do some wind generation, but I am under
the jurisdiction of the California Costal Commission.
The rule is no visible windmills. However, where
there's a will there's a way. I will be putting large
eaves on my barn(workshop) on the windward side to
pressurize the building and will use this to spin a
blade on the downwind side of the building. The
building faces the ocean and gets a nice daily breeze.
Sometimes we get some really nasty winds so I will
have to have some provision to close these off in a
storm.
Reverend "off the grid" Gadget
_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar � get it now!
http://clk.atdmt.com/AVE/go/onm00200415ave/direct/01/
--- End Message ---
--- Begin Message ---
--- Tim Clevenger <[EMAIL PROTECTED]> wrote:
> Check out the current issue of Homepower. A family
> there ended up with a
> bit
> over 53% of their PV setup paid for by the state
> (between the CA rebates and
> the state tax deduction.)
>
> Tim
Doesn't one have to be able to connect to the grid to
get the incentives? The nearest grid conection is 1/2
mile away. The price for easements and laying in the
grid tie would be eat up any incentives the goverment
would give me. I have a neighbor who wants $10,000 to
cross his property and will only let me go
underground. That'll pay for a lot of solar panels.
Gadget
=====
visit my website at www.reverendgadget.com
--- End Message ---
--- Begin Message ---
Hm. I thought the fuses were filled with sand for this reason: When the
fuse blows and the arc forms the heat turns the sand into glass which
becomes the insulator that puts the arc out.
Chris
Lee Hart wrote:
David Chapman wrote:
Bill Griffen was building just such a fuse holder out of Delrin
Delrin would be a bad choice. It melts and it burns. Not good things for
a fuseholder. Most commercial fuseholders (that are UL list and so have
actually been tested) are made of bakelite, phenolic, ceramic,
fiberglass, etc.
Ruch Rudman wrote:
I have never had a fuse part. I don't think it's a real issue.
They won't for a modest overload (like 4x of rated current). But they
can and do for a major overload (like 10x to 100x rated current)! I've
seen UL movies of fuse tests where they did this, and they are
impressive!
Ever seen the 'exploding wire' trick? Charge up a big capacitor to a
couple hundred volts. Short it thru a small piece of wire. The wire goes
*KABOOM* just like a firecracker. It will also blow holes in things just
like a firecracker. (I do it with a 1000uF capacitor, mercury switch in
series with a few feet of #18 AC line cord, with just one strand
shorting the far end together. Charge up the capacitor to a few hundred
volts, tip it over so the mercury switch shorts, and BANG!)
Now, the fuse link inside a fuse is just such a little wire (you'd be
amazed at how small it is in a high-current fuse). The controller
provides just such a set of high-current capacitors. All you need is a
nice, solid short circuit. What do you think a firecracker going off
inside your fuse would do?
Normally, an excess current just melts the metal fuse link. The molten
metal just drips away from gravity to open the circuit. There will be
some arcing when the gap first opens, and that may vaporize a little
metal, but not much.
At very high currents, the metal melts, but then the liquid metal
continues to carry current. Before gravity can pull it away, the liquid
metal vaporizes. Converting the metal into gas causes a large increase
in pressure inside the fuse. Meanwhile, the arc through the ionized gas
just heats it further. The superheated gas pressure finally blows the
fuse apart.
I've exploded lots of glass 3AG type fuses (the 1.25" x 0.25" diameter
ones); just put an AC rated one in a DC circuit. The ceramic ones are
much tougher, but I've still done it. I've blown the ends off the cheap
phenolic tube fuses used in household wiring too, in my old Datsun with
its golf cart batteries when the contactor controller failed (probably a
10x overload on a 200a fuse).
I now will use only the DC-rated "semiconductor" fuses in my EVs. You
can tell they are built to mightily resist exploding. The Gould "Shawmut
Amptrap" A50P300 I have in my LeCar EV is rated 500vdc, 300amps, 10,000
amps interruting capacity (shouldn't explode at under 10,000 amps). It
has a 1/8" wall thickness fiberglass tube for a body, with 4 1/8" pins
at each end to hold in the massive cast copper endcaps. The fuse element
inside is pure silver, packed in sand. It's mounted on two phenolic
standoffs with 5/16" studs embedded in it, bolted to a 1/8" aluminum
plate. I fugure that ought to do it! :-)
Victor Tikhonov wrote:
This is a holder for a liquid hose of an ICE, and made from high
temp withstanding plastic, not polyethylene (or such) thermoplastic.
That clamp only has to survive boiling water; that's not very hot at
all. Try running rated current thru a fuse for a while, and notice how
hot it gets. The Gould A50P300 I use measures 0.0004 ohms. At its rated
current (300a) it is dissipating P = I^2 x R = 36 watts. That's a LOT
for a device only 4" long and 1.5" diameter. Think about how hot a 40w
light bulb gets, and it's about the same size. Another part of the job
for a good heatsink is to dissipate this heat.
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Joe Smalley wrote:
>
> OK. What is the question?
>
> I was suggesting that a DC input PFC-50 can run at 100 amps if the input
> rectifiers were eliminated. If you run the DC through the rectifiers, the
> heat sink will heat up and cut the power back to 75 amps just like normal. I
> doubt that you can run 100 amps continuous through a PFC-50 with the
> rectifiers hooked up especially in the southwestern summers.
>
> You might put a relay in the system that bypasses the rectifiers when fed
> from a DC source. That would drive the cost up but would increase the power
> level. You could also do an interlock to keep the AC from feeding out the DC
> input or vice versa. The DC sensor can also reprogram the calibration
> resistors to make the machine make the same current regardless of input
> voltage. The problem with this is, it disables the PFC on the DC setting
> which you don't need in that configuration.
>
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> [EMAIL PROTECTED]
>
The line rectifiers are less than %20 of our total losses.
The big questions is ouput AMPS. Or if we are trying to feed a 50 with
100 amps of 24 volts, or something else that requires almost %100 pwm on
one of the Igbts.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
--- Rich Rudman <[EMAIL PROTECTED]> wrote:
I can build the dump pack to any voltage I want in
multiples of 24V easily. I use 24V panels and charge
controllers. I can daisy chain the systems to whatever
voltage. So there is no need to make the PFC-50 work
that hard. Does that help?
Gadget
> The line rectifiers are less than %20 of our total
> losses.
> The big questions is ouput AMPS. Or if we are
> trying to feed a 50 with
> 100 amps of 24 volts, or something else that
> requires almost %100 pwm on
> one of the Igbts.
>
>
> --
> Rich Rudman
> Manzanita Micro
> www.manzanitamicro.com
> 1-360-297-7383,Cell 1-360-620-6266
>
=====
visit my website at www.reverendgadget.com
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>
>
> Delrin would be a bad choice. It melts and it burns. Not good things for
> a fuseholder. Most commercial fuseholders (that are UL list and so have
> actually been tested) are made of bakelite, phenolic, ceramic,
> fiberglass, etc.
>
> Ruch Rudman wrote:
> > I have never had a fuse part. I don't think it's a real issue.
>
> They won't for a modest overload (like 4x of rated current). But they
> can and do for a major overload (like 10x to 100x rated current)! I've
> seen UL movies of fuse tests where they did this, and they are
> impressive!
Ok Lee, we are actually on the same page here!
I use the Little Fuse semiconductor fuse rated at 500 VAC and 450 VDC.
I use 3 different sizes from the 30 amp cartridge fuse to the 100 amp
stud mount.
I have %100 confidence that they will open what ever disaster I throw at
them. I have had a couple of the 30 ampers get really hot without
opening. No fault currents just %96 of rating for hours on end. We don't
do that anymore.....
A good fuse is NOT cheap. Beware the $5 AC fuse. I have boxes of them,
and Most of us Evers use them, But you won't find a AC(only) rated fuse
inside a Manzanita charger.
You might on the Dyno....
Delrin is for Racing suspension joints. Remove the rubber, replace with
Delrin, feel every pebble!!! Feel the tires grip!!! Goldie has a few of
these in her.
I need to mount the stearing rack with delrin, the rubber one is the
major cause of front aligmnet problems under.... Madman spec, Raptor
powered launches.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
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I am still hunting for my donor car. I want to use a small light, car
2dr hatchback with enough room for a 6'2" driver. Max 2 passengers. I
have been looking at Geo Metros, Fireflys and Swifts (1995 and better)
however the payload is not all that good. The Mazda 323 payload looks
better. Anybody have any other suggestions or recommendations?
thanks
Don
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Peter VanDerWal wrote:
> I don't think Tektronics makes a "bad" scope. It might have more
> features than you need, but that's ok.
I agree -- their older scopes are truly great pieces of equipment. Just
avoid their "Telequipment" line (the el-cheap ones intended for TV
servicemen and college labs). They are still good, but not great. Used
test equipment depreciates so much that you might as well get the good
ones. And the 475 is very good!
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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--- Begin Message ---
Thanks Lee.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: March 12, 2004 11:28 AM
To: [EMAIL PROTECTED]
Subject: Re: Tektronix 475 Scope
Peter VanDerWal wrote:
> I don't think Tektronics makes a "bad" scope. It might have more
> features than you need, but that's ok.
I agree -- their older scopes are truly great pieces of equipment. Just
avoid their "Telequipment" line (the el-cheap ones intended for TV
servicemen and college labs). They are still good, but not great. Used
test equipment depreciates so much that you might as well get the good
ones. And the 475 is very good!
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Mark Hanson [mailto:[EMAIL PROTECTED] wrote:
> I was told by Trojan that ripple current vs DC charging
> didn't have any effect on the battery, just getting the 110%
> AH used back in.
US Battery and Trojan have both told me the same thing, however, I don't
know just how closely they have investigated this. IF US Battery
products do need the minimum inrush current claimed in order to provide
decent life, and IF there are people charging at less than the C/10 rate
that are getting decent life from them (such as yourself), then it seems
possible that the high peak currents associated with typical chargers
may allow the minimum charge rate requirement to be satisfied with a
charger whose average output otherwise appears too low.
If you know, or can measure, the ripple on your charger's output current
it would be a most useful datapoint, since you are getting decent life
from your US125s despite using a lower than recommended average charge
current.
> It is possible
> that Steve is seeing shortened life on the batteries due to
> the high current draw of twin 400A controls/motors without
> the benefit of a transmission. It would be interesting to
> know if all Tropica drivers experience this same phenomenon.
It would indeed be interesting to know, although I don't know that there
are enough Tropicas out there for a statistically significant sample!
Cheers,
Roger.
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Roger,
In a message dated 3/12/2004 4:16:07 PM Eastern Standard Time, [EMAIL PROTECTED]
writes:
> It would indeed be interesting to know, although I don't know that there
> are enough Tropicas out there for a statistically
> significant sample!
>
Well yes that would be a problem. Right now I know of only 3 running Tropicas with
original controllers and flooded batteries. Brad just installed his batteries so we
can't count him yet and I sent an email to the other owner. I belive he's on his first
pack but I have no idea of his mileage. None of us are using the original charger.
There are 2 other cars that I believe are totally original (maybe more) but they are
not in running condition.
> Cheers,
>
> Roger.
Steve
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--- Begin Message ---
Reverend Gadget wrote:
>
> --- Rich Rudman <[EMAIL PROTECTED]> wrote:
> I can build the dump pack to any voltage I want in
> multiples of 24V easily. I use 24V panels and charge
> controllers. I can daisy chain the systems to whatever
> voltage. So there is no need to make the PFC-50 work
> that hard. Does that help?
>
> Gadget
Set them all up in series for the most voltage you dare.
240 would be nice.
Target pack voltage??
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
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--- Begin Message ---
Joe, Here is a three speed contactor controller design from Lee Hart using
3 12v batteries and two contactors. I used this successfully on a minibike
with an 6.7" ADC and 55 Ahr batteries.
http://www.austinev.org/evalbum/439.html (Note: photo shows original 1 HP
motor)
View as fixed width font.
____
/ \
/ \ \
_____| Motor |____ \__
| \ / |
| \____/ Safety |
| Disconnect |
| |
| |
| | | |
| ---||||------------|
| | | | |
| | 24v |
| | ---
| |---------||---| /\ D2
| | |
| R2 | |
| | | |
| ----||-------------|
| | | |
| | 12v ---
| | /\ D1
| |---------||---| |
| | |
| R1 | |
|------------------------|
Switch logic Batteries
In use
Speed R1 R2 Volts 12v 24v disconnect
0 0 x
1 x 12 x x
2 x 24 x x
3 x x 36 x x x
Charging: each battery separately
>
> My five year old told me tonight that he needs bigger batteries. Two SVRs
> just are not enough range for him. He ran them dead between noon and five
> p.m.. I asked him if he wanted to go faster or farther. He chose faster. I
> have a third SVR coming to upgrade from 24 volts to 36 volts. I will have
to
> bypass the series\parallel switch on the dash to use 36 volts. Three SVRs
> fit very snugly under the hood but the hood actually closes properly.
>
> I have reservations about connecting 36 volts of SVRs to the motor at a
> stop. I expect it to wheelie in forward and wear out the tires in reverse.
I
> thought a resistor in series with the motor would cut the torque from a
> stop. The contactor controller could then either sense the voltage across
> the resistor to tell when to hit the direct contactor or just use a timer
to
> hit the direct contactor. It could be inhibited to keep the direct
contactor
> from activating in reverse. We caught the neighbor kid doing roll backs in
> the yard trying to get it to wheelie. It would do very good wheelies if
> there was a third kid standing on the rear bumper holding onto the roll
bar.
>
> Joe Smalley
>
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At 11:11 AM 3/12/04, you wrote:
I am still hunting for my donor car. I want to use a small light, car
2dr hatchback with enough room for a 6'2" driver. Max 2 passengers. I
have been looking at Geo Metros, Fireflys and Swifts (1995 and better)
however the payload is not all that good. The Mazda 323 payload looks
better. Anybody have any other suggestions or recommendations?
Whatever you do, DO NOT buy a "fixer upper". Buy a car that you
would be proud to drive in the condition that it is in. You will spend much
more money restoring a crappy car to acceptable condition than you would
spend simply buying a nice car to begin with. This is true even if you do
all the work yourself!
Of course, a blown engine is perfectly acceptable.
Even though body, bumper, and trim parts are expensive and hard to
find, my favorite car to convert is a VW Karmann Ghia. You need to find one
that is in near pristine condition. This will cost about $4,000. Like:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=15293&item=2462567902
There are several things that make a Ghia a great conversion. They
have a low drag coefficient. They are lightweight. The suspension is very
rugged, inexpensive to "soup up", and can easily handle the extra weight of
the batteries. Adapter plates and couplers are easy to find, as are the
plans for adapter plates and couplers. There is plenty of room for a
typical battery pack. Mechanical parts (like brakes, ball joints,
transmissions, etc) are very inexpensive and easy to find.
My second choice is a Porshe 914. The disadvantage of the 914 is
that the mechanical parts are significantly more expensive than a Ghia.
The best W-hr/mile figure I have ever heard of in a home built was
John Bryan's Ghia. I believe the number was 135 W-hrs/mile (or something
near that) in mixed highway and city driving. For comparison, my Wabbit
(VW Cabriolet) best numbers never get below 212 W-hr/mile.
_ /| Bill "Wisenheimer" Dube'
\'o.O' <[EMAIL PROTECTED]>
=(___)=
U
Check out the bike -> http://www.KillaCycle.com
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On 12 Mar 2004 at 15:52, [EMAIL PROTECTED] wrote:
> Whatever you do, DO NOT buy a "fixer upper".
I agree with Bill here. Start with something in good shape. Also make sure
you can get parts for it readily, unless you don't plan on making it a daily
driver.
Old cars (including such classics as the Karmann Ghia) have the advantage of
being appreciably lighter than newer ones. But parts are often a headache.
And even if they're in top shape, they don't have modern collision
protection design, so their safety is compromised. Your modifications will
make this worse, so I think it's better to start with the newest car you can
afford.
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Want to unsubscribe, stop the EV list mail while you're on vacation, or
switch to digest mode? See http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1970 GE Elec-trak E15 36vdc
1974 Avco New Idea rider 36vdc
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
On two occasions I have been asked [by members of Parliament!],
"Pray, Mr. Babbage, if you put into the machine wrong figures, will
the right answers come out?" I am not able rightly to apprehend the
kind of confusion of ideas that could provoke such a question.
-- Charles Babbage
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
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Hi Don,
I like my Porsche 914 very much, though I wish I'd gotten one with a
bit less rust...they're difficult to find in good condition without
spending lots of money. Either people love them and keep them mint, or
they neglect 'em and sell them for reasonable prices. I got lucky as
mine was missing its engine but still in pretty decent condition. More
restoration than I'd initially planned on, but still not *too* bad. I
hear that tall people have an easy time fitting the 914, so that might
be a plus for you.
Geo metros are converted relatively often, though they feel like
driving a tin can and make lots of road noise. Have you considered a
Honda Civic? Or I know John Wayland is particularly fond of the Datsun
1200's for being light, though they might be difficult to find/get
parts for.
Hope this helps
-Ben
On Mar 12, 2004, at 1:11 PM, Don Cameron wrote:
I am still hunting for my donor car. I want to use a small light, car
2dr hatchback with enough room for a 6'2" driver. Max 2 passengers. I
have been looking at Geo Metros, Fireflys and Swifts (1995 and better)
however the payload is not all that good. The Mazda 323 payload looks
better. Anybody have any other suggestions or recommendations?
thanks
Don
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--- Begin Message ---
All,
I didn't see posts here that someone actually
installed this EV mode switch on his/her '04 Prius. I
just want to share what I found.
I installed a temporary switch last weekend just to
see how useful it really is in real life. I think I
am going to make it permanent. I used it when I
needed to move it in and out from the garage, when I
just wanted to test the 12V inverter, on trips home
from a nearby restaurant, and even in traffic bottle
necks. The longest I have driven on EV mode is 1.7
miles, and that was without a fully charged pack (from
the energy screen).
In EV mode, you are able to get decent acceleration
and a max speed of 34MPH. If you accelerate any
faster or if you exceed 34MPH, the computer would give
3 beeps and go to normal mode.
My wife and I both commute in our EVs. And, we are
quite impressed with what the Prius could do so
effortlessly. Now, we only need a bigger battery pack
and a way to recharge it from the grid! It looks like
the pack could be recharged from the grid now without
the computer complaining if you leave the car at
"Ready" mode. We are very close to having a gridable
hybrid.
Ed Ang
__________________________________
Do you Yahoo!?
Yahoo! Search - Find what you�re looking for faster
http://search.yahoo.com
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--- Begin Message ---
At 10:00 PM 9/03/04 -0800, Lee Hart wrote:
James Massey wrote:
> I pulled apart a very old 72V 3600VA (rated input 240V 15A) charger <snip>
Sorry for being slow to get back to you on this, James. I was travelling
last week.
Up to a point, better late than never (unless you're the fire department).
However, I've progressed to the point where I have made up new formers and
got them around to the winding shop to be done. However, it's nice to
confirm what needs to be done.
> The transformer is 'I' laminates, of two different lengths, lapped
> up to form a single-loop core:
That's a fairly common core structure when you are only going to make a
small number of transformers. It's easier to stackup the I's, wind them,
then assemble the core together. With conventional E-I laminations, you
have to wind some kind of bobbin, then insert the E's and I's into it.
Yes, I realised that it was an easy reassemble, which is one reason I went
ahead :^)
> I assume that the limit on the charging current is either by turns
> per volt, or purely that the taps are selected to set the current
> when matched to the battery.
Right. This core appears to develop about 1 volt per turn. So you just
need to figure out how many turns need to be in the primary and
secondary for the voltages desired.
Have done. Although with little to be an absolute guide, I have done
everything to the secondaty as a ratio to what there was. On the primary I
am having on the fine tap side taps put every 4 turns, instead of every 6
turns, plus an extra 4 turns on the end.
> The transformer design is that the primary is wound on first, half
> on each side of the core, with the secondary on top, half on each
> side...
Again, that is quite normal. The primary usually has the highest
voltage, and so the most turns of the smallest wire. They wind it on the
core first, because the wire bends easier.
<snipped the turns sketch>
This transformer has a useful number of taps as-is. You may not need to
rewind it at all.
If it was originally wound for 72vdc (with two diodes in a full-wave
center-tapped arrangement, then for 144v, all you need to do is connect
a bridge rectifer across the ends. You can then adjust the output
voltage and current with the primary taps in 6-turn increments.
Unfortunately it went to a full-wave bridge, so unless I tried to get it
with voltage-doubling rectification, I was stuck.
> I was expecting to find the same number of secondary turns on each
> half. Should I maintain the offset ratio of secondary turns?
Like a toroid, what counts as a 'turn' is anything that goes thru the
hole in the center. Even though you list 46 and 47 turns, you will
probably find that the wires are arranged so each half goes thru the
center exactly the same number of times.
I was expecting the same number, but the good thing about the aluminium
strap, I had plenty of space to write the turn number on it at each turn as
it came off (to make sure if I was interrupted I didn't loose count). And I
checked, and re-checked. 46 turns on one, 47 turns on the other. So this
had me woried - was this some cunning old-time 'trick' to force current
limiting? aparently not, just a get-around from needing either a half-turn
to get the calculated voltage, or just a 'get as many turns on' until they
ran out of space.
> The primary was wound <snip> can carry 29.7 amps at 700 cm/amp. So
you're right; this is a
pretty conservative wire size.
good, I specified wire around 3mm diameter, so that should still be OK. The
secondary is to be done in a rectangular wire of 4mm x 4.5mm.
--
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
Thanks Lee, yet again.
James Massey
Launceston, Tasmania, Australia.
'78 Daihatsu truck
* Body prepared
* ceramic heater installed
* seats away being re-upholstered
* motor away having final modifications
* charger transformer away being rewound
* Battery box under construction (by me)
* batteries, controller, vac pump and other parts waiting to be installed
* battery regulation and monitoring systems being defined and designed.
* and a 'rats nest' of wire to be tamed.
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