EV Digest 4529
Topics covered in this issue include:
1) Re: Electric Vehicle Help
by Neon John <[EMAIL PROTECTED]>
2) Re: PFC Chargers...Let's hear the Positive Side!
by "ProEV" <[EMAIL PROTECTED]>
3) Re: PFC Chargers...Let's hear the Positive Side!
by Danny Miller <[EMAIL PROTECTED]>
4) Re: Quit scaring me - battery killing
by [EMAIL PROTECTED] (Chris Buresh)
5) Re: PFC Chargers...Let's hear the Positive Side!
by "Rich Rudman" <[EMAIL PROTECTED]>
6) RE: 1965 Datsun Truck - Future Electric Vehicle
by "damon henry" <[EMAIL PROTECTED]>
7) Re: 1965 Datsun Truck - Future Electric Vehicle
by "Tim Humphrey" <[EMAIL PROTECTED]>
8) Re: Air conditioner...2-step starter
by Lee Hart <[EMAIL PROTECTED]>
9) Re: And you thought diamonds are only a girls best friend
by Lee Hart <[EMAIL PROTECTED]>
10) Re: Best point to charge?
by Lee Hart <[EMAIL PROTECTED]>
11) Re: EV Vehicle choice
by [EMAIL PROTECTED]
12) Re: More questions E-meter serial port
by Lee Hart <[EMAIL PROTECTED]>
13) Re: 1965 Datsun Truck - Future Electric Vehicle
by Lee Hart <[EMAIL PROTECTED]>
14) Re: Electric Vehicle Help - Thanks for the Advice
by Rex Allison <[EMAIL PROTECTED]>
15) RE: Electric Vehicle Help
by Reverend Gadget <[EMAIL PROTECTED]>
16) Re: Electric Vehicle Help - Thanks for the Advice
by "Tim Humphrey" <[EMAIL PROTECTED]>
17) Re: More questions E-meter serial port
by "Peter VanDerWal" <[EMAIL PROTECTED]>
18) Re: More questions E-meter serial port
by "Peter VanDerWal" <[EMAIL PROTECTED]>
19) Re: Quit scaring me - battery killing
by Lee Hart <[EMAIL PROTECTED]>
20) Re: Hello and quit scaring me.
by [EMAIL PROTECTED]
--- Begin Message ---
On Tue, 26 Jul 2005 07:52:00 -0500, "ohnojoe" <[EMAIL PROTECTED]>
wrote:
>If all fails, visit another DMV.
>I'd mess with odometer reading as a vary last resort.
>AS someone suggested, you can always say that the odomerer
>itself is new but the vehicle is not so new.
>They are the ones who made these stupid regulations
>so difficult, so you play their game too.
I suggest not falsifying the odo reading. Thanks to the antics of
people in my town here(Two "60 minutes visits", federal investigation,
dozens sent off to Club Fed in Atlanta, etc), odo
tampering/rollback/falsifying is now a federal felony. Everything else
that's been discussed of working around the law (stupid, IMO, since
he's in the right in the first place) are minor state misdemeanors. I
don't think anyone wants to risk a felony.
Just call the state, get it straightened out and do it right. The fix
is probably a phone call away.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
--- End Message ---
--- Begin Message ---
Hi Rich,
I found a voice message on my Cell... have we covered it on the list???
I was calling to see about sending in the PFC50 to fix the GFI trip problem.
You might remember that I called about two months ago because the charger
started tripping the GFI all the time. You suggested taking off the case and
blowing off the boards. If that did not work, I was to send it back to you
(for plastic stand-offs?). I pulled the cover. There was very little dust
but I blew anyway. Sure enough, this cured the GFI trip.
The GFI problem came back after about a week. Since we had 2 races and an
autocross coming up, I just pulled out the GFI breaker.
Now we have a bit of a break from racing. So I would like to fix the GFI
problem. If you feel any other updating would be useful, I would like to get
that done too.
If we should discuss it over the phone, I can be reached at 305 610 6412.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
First just take an ohmmeter and see if the ground has any resistive
connection at all to either AC wire. This doesn't always happen with
ground faults, and if it's intermittent you may not see it either, but
it's a start.
Common cause of ground faults is failed insulators, btw. It's a good
place to start.
Danny
ProEV wrote:
Hi Rich,
I found a voice message on my Cell... have we covered it on the list???
I was calling to see about sending in the PFC50 to fix the GFI trip
problem.
You might remember that I called about two months ago because the
charger started tripping the GFI all the time. You suggested taking
off the case and blowing off the boards. If that did not work, I was
to send it back to you (for plastic stand-offs?). I pulled the cover.
There was very little dust but I blew anyway. Sure enough, this cured
the GFI trip.
The GFI problem came back after about a week. Since we had 2 races and
an autocross coming up, I just pulled out the GFI breaker.
Now we have a bit of a break from racing. So I would like to fix the
GFI problem. If you feel any other updating would be useful, I would
like to get that done too.
If we should discuss it over the phone, I can be reached at 305 610 6412.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
What type of considerations need to be made for winter driving? How long can
batteries sit in 20F weather before freezing? I most likely will store the
vehicle to protect the structure. How do I keep the batteries alive in my cold
garage?
--
Chris Buresh
St. Paul, MN
-------------- Original message --------------
> Hi Everyone..again (I'm catching up on things, can you tell?)
>
> Ken wrote:
>
> >However, in the email today was a comment that is a
> >bit off-putting to a newbie. Something to the effect
> >that everyone fries their first battery pack. I
> >really, really don't want to do that. My wife already
> >thinks this is a crazy idea and if I kill $2k in
> >batteries, she'll probably kill me. Please, someone
> >reassure me that with proper precautions I can charge
> >the battery pack without frying them. Then tell me
> >what those precautions are.
> >
> I've been driving my conversion for about 8 months now. In my
> "younger", "newbie" days (I've still got lots to learn), I was petrified
> of killing my Orbitals. I treated them very carefully, and they have
> treated me good in return.
>
> A few suggestions that some others have made, but I'll reiterate:
>
> * Get an e-meter! You might think you can do without this several
> hundred dollar expense, but it helps so much to know what is going on
> when you are charging (and discharging - I don't have mine within driver
> view. I am building an interface to the RS-232 output to drive my stock
> fuel gauge).
> * Don't plan on pushing your vehicle in the first month or so. If you
> have calculated that you will be able to go 20 miles on a 80% depth of
> discharge (i.e. for example with an Orbital that has a resting voltage
> of about 13V and "empty" at around 12V, 80% depth of discharge (DOD)
> would be about 12.2V...after if has rested for quite a few hours - like
> 12 or more), oh, where was I...oh, if you calculate 20 miles at 80% DOD,
> then don't go more than 10 or so for awhile. I'd say go even less if
> it's cold, e.g. less than 50.
> * Make sure you know what's going on before you start charging. Of
> course you won't know or understand everything, but ask lots of
> questions and understand your charging hardware.
>
> I welcome any clarifications, additions, or corrections to my suggestions.
>
> -Ryan
> --
> - EV Source -
> Zillas, PFC Chargers, and Netgain WarP motors at great prices!
> E-mail: mailto:[EMAIL PROTECTED]
> Toll-free: 1-877-215-6781
>
--- End Message ---
--- Begin Message ---
Sounds good to me.
Rich
----- Original Message -----
From: "ProEV" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, July 26, 2005 8:01 AM
Subject: Re: PFC Chargers...Let's hear the Positive Side!
> Hi Rich,
>
> > I found a voice message on my Cell... have we covered it on the list???
> >
> I was calling to see about sending in the PFC50 to fix the GFI trip
problem.
>
> You might remember that I called about two months ago because the charger
> started tripping the GFI all the time. You suggested taking off the case
and
> blowing off the boards. If that did not work, I was to send it back to you
> (for plastic stand-offs?). I pulled the cover. There was very little dust
> but I blew anyway. Sure enough, this cured the GFI trip.
>
> The GFI problem came back after about a week. Since we had 2 races and an
> autocross coming up, I just pulled out the GFI breaker.
>
> Now we have a bit of a break from racing. So I would like to fix the GFI
> problem. If you feel any other updating would be useful, I would like to
get
> that done too.
>
> If we should discuss it over the phone, I can be reached at 305 610 6412.
>
> Cliff
>
> www.ProEV.com
>
>
>
>
--- End Message ---
--- Begin Message ---
I don't think that 13 Optima's will give you the range you want, at least
not for long, as you will be discharging them too deeply. This is about the
max range of Blue Meanie with the same battery pack. Blue Meanie is lighter
and more efficient than your truck is going to be. Why limit yourself to
156v? Just get the Higher voltage Zilla controller and add a few more AGMs
to the string. Now you should be able to find the perfect balance you are
looking for.
damon
From: "Pestka, Dennis J" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: RE: 1965 Datsun Truck - Future Electric Vehicle
Date: Tue, 26 Jul 2005 07:19:25 -0500
Lee;
Thanks for the response.
The other thing I'm trying to juggle in the equation is the weight of a my
battery pack and how it affects performance.
This vehicle weighs in at about 2085#, with a GWR of almost 4000#.
I figure after stripping off everything I can get down in the 1700# range.
I'm guessing that after conversion, "less batteries", I will be in the
1950#
range.
A pack of 20 T-105's will add 1220# bringing total weight to ~ 3170#.
If I go with sealed batteries, I can reduce that weight significantly.
(13) Optima's = 2535#.
This 635# reduction in weight and higher voltage will also make a
difference
in how this vehicle performs.
The million dollar question is, will it give me the range I desire, ~ 20
mile range most of the time, with a 30 mile range on occasion, and not kill
my pack in a short period of time.
After spending years with the flooded batteries with my tractors, I also
must admit I'm really interested in trying something new. The sealed
battery
features of a clean, maintenance free installation sounds very tempting.
Thanks;
Dennis
-----Original Message-----
From: Lee Hart [mailto:[EMAIL PROTECTED]
Sent: Monday, July 25, 2005 3:59 PM
To: [email protected]
Subject: Re: 1965 Datsun Truck - Future Electric Vehicle
Pestka, Dennis J wrote:
> I am looking for advice because I am really torn between performance
> and range. I live in a rural area and the nearest town is 9 miles and
> a more frequented town is 15 miles each way... My hope is to get some
> of the students at my wife's school interested in Electric Vehicles.
It all depends on what you mean by performance.
To an enthusiast, "high performance" means the vehicle does something
exceptionally well; far better than normal cars. Very fast straight-line
accelleration, or extremely fast cornering for example. The car might look
like a wreck and be impossible to drive on a daily basis; but it wins
races!
But to most people (and probably the vast number of high school kids), the
*appearance* of performance is more important than the actual numbers. A
fancy paint job counts more than good aerodynamics. Wide tires matter more
than good handling. A loud engine means more than real horsepower.
Tire-burning matters more than actual accelleration. A loud stereo matters
more than racing gauges.
This means you can have a car that *appears* to be high-performance, and
will impress the heck out of the average kid or young adult. But in fact,
it
can have performance of the sort that impresses your wife as a daily
driver.
Her definition of "performance" probably means "keeps up with normal
traffic, and is smooth, quiet, comfortable, easy to drive, and great
operating economy and reliability".
EVs have unique abilities that allow them to meet both sets of requirements
simultaneously.
For example, even a smallish series motor can produce astounding amounts of
torque. Even an 8" Advanced DC motor can provide impressive tire-burning
take-offs and very fast accelleration at low speeds. With its rear wheel
drive and battery weight in back, you can make it so fast that nothing in
the school parking lot could match its 0-30 mph time!
But you can still use big old flooded batteries for long life, good range,
and economy. No casual onlooker knows the difference between a Trojan and
an
Optima. So use the floodeds to cut your battery cost in half. With 20 6v
golf cart batteries, you have enough energy for your
30+mile range, yet plenty of power for showing off.
A Zilla controller can be set to give you 1000+ motor amps for
neck-snapping
accelleration, but limit battery current to 250 amps for long life and good
range. The side effect is that performance at high speed is limited; you
have to climb hills slower, and it accellerates worse at high speeds.
John Wayland has hit on the "magic" formula for impressing people with his
EVs. Gorgeous paint jobs, immaculately restored interiors, powerful
stereos,
and car-show-quality construction and detailing make his EVs
*very* impressive. But none of these things prevent you from having a
completely mundane, normal-performing daily driver.
Now for the wife-performance factors: Find out what *she* looks for in a
great car. If she's like mine, she wants silent operation, smooth riding,
and very easy to drive (no shifting, power steering and brakes, power
everything, etc.). No funny meters or switches or other gadgets to mess
with.
These are easy on an EV. They are naturally quiet. Even with a manual
transmission, you can provide it with electric reverse she can just leave
it
in one gear all the time. You can add power steering and brakes. An
impressive stereo is a great touch. Loud is fine (to impress others), but
she may be more interested in a satellite radio or MP3 player.
Extra convenience features that you can't get on normal cars are a big
plus.
For instance, she never has to go to a gas station. The heater and air
conditioner can be set up to run even when the car is parked, so she can
come out to a comfortable car in the heat or summer or dead of winter.
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading Or do the great deeds worth
repeating
-- Ben Franklin, Poor Richard's Almanac
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
That's why I suggested 30 Orbitals. You would still have the 1200 lbs of lead
for the range, but you would also have
close to 350 battery hp available, as opposed to what...65-70 battery hp for
the flooded pack. Sure it'll cost more,
but it'll be a more pleasant experience and the AGM pack should last longer,
and require much less maintenance.
Or you can wait 'til next spring and hopefully I can score some more NiCads. I
just missed a batch, anybody know Norm
Fife?
--
Stay Charged!
Hump
"Ignorance is treatable, with a good prognosis. However, if left untreated, it
develops into Arrogance, which is often
fatal. :-)" -- Lee Hart
Get your own FREE evgrin.com email address;
send a request to ryan at evsourcecom
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of damon henry
> Sent: Tuesday, July 26, 2005 11:30 AM
> To: [email protected]
> Subject: RE: 1965 Datsun Truck - Future Electric Vehicle
>
> I don't think that 13 Optima's will give you the range you want, at least
> not for long, as you will be discharging them too deeply. This is about the
> max range of Blue Meanie with the same battery pack. Blue Meanie is lighter
> and more efficient than your truck is going to be. Why limit yourself to
> 156v? Just get the Higher voltage Zilla controller and add a few more AGMs
> to the string. Now you should be able to find the perfect balance you are
> looking for.
>
> damon
>
>>From: "Pestka, Dennis J" <[EMAIL PROTECTED]>
>>Reply-To: [email protected]
>>To: [email protected]
>>Subject: RE: 1965 Datsun Truck - Future Electric Vehicle
>>Date: Tue, 26 Jul 2005 07:19:25 -0500
>>
>>Lee;
>>
>>Thanks for the response.
>>
>>The other thing I'm trying to juggle in the equation is the weight of a my
>>battery pack and how it affects performance.
>>
>>This vehicle weighs in at about 2085#, with a GWR of almost 4000#.
>>I figure after stripping off everything I can get down in the 1700# range.
>>I'm guessing that after conversion, "less batteries", I will be in the
>>1950#
>>range.
>>
>>A pack of 20 T-105's will add 1220# bringing total weight to ~ 3170#.
>>If I go with sealed batteries, I can reduce that weight significantly.
>>(13) Optima's = 2535#.
>>
>>This 635# reduction in weight and higher voltage will also make a
>>difference
>>in how this vehicle performs.
>>
>>The million dollar question is, will it give me the range I desire, ~ 20
>>mile range most of the time, with a 30 mile range on occasion, and not kill
>>my pack in a short period of time.
>>
>>After spending years with the flooded batteries with my tractors, I also
>>must admit I'm really interested in trying something new. The sealed
>>battery
>>features of a clean, maintenance free installation sounds very tempting.
>>
>>Thanks;
>>Dennis
>>
>>-----Original Message-----
>>From: Lee Hart [mailto:[EMAIL PROTECTED]
>>Sent: Monday, July 25, 2005 3:59 PM
>>To: [email protected]
>>Subject: Re: 1965 Datsun Truck - Future Electric Vehicle
>>
>>Pestka, Dennis J wrote:
>> > I am looking for advice because I am really torn between performance
>> > and range. I live in a rural area and the nearest town is 9 miles and
>> > a more frequented town is 15 miles each way... My hope is to get some
>> > of the students at my wife's school interested in Electric Vehicles.
>>
>>It all depends on what you mean by performance.
>>
>>To an enthusiast, "high performance" means the vehicle does something
>>exceptionally well; far better than normal cars. Very fast straight-line
>>accelleration, or extremely fast cornering for example. The car might look
>>like a wreck and be impossible to drive on a daily basis; but it wins
>>races!
>>
>>But to most people (and probably the vast number of high school kids), the
>>*appearance* of performance is more important than the actual numbers. A
>>fancy paint job counts more than good aerodynamics. Wide tires matter more
>>than good handling. A loud engine means more than real horsepower.
>>Tire-burning matters more than actual accelleration. A loud stereo matters
>>more than racing gauges.
>>
>>This means you can have a car that *appears* to be high-performance, and
>>will impress the heck out of the average kid or young adult. But in fact,
>>it
>>can have performance of the sort that impresses your wife as a daily
>>driver.
>>Her definition of "performance" probably means "keeps up with normal
>>traffic, and is smooth, quiet, comfortable, easy to drive, and great
>>operating economy and reliability".
>>
>>EVs have unique abilities that allow them to meet both sets of requirements
>>simultaneously.
>>
>>For example, even a smallish series motor can produce astounding amounts of
>>torque. Even an 8" Advanced DC motor can provide impressive tire-burning
>>take-offs and very fast accelleration at low speeds. With its rear wheel
>>drive and battery weight in back, you can make it so fast that nothing in
>>the school parking lot could match its 0-30 mph time!
>>
>>But you can still use big old flooded batteries for long life, good range,
>>and economy. No casual onlooker knows the difference between a Trojan and
>>an
>>Optima. So use the floodeds to cut your battery cost in half. With 20 6v
>>golf cart batteries, you have enough energy for your
>>30+mile range, yet plenty of power for showing off.
>>
>>A Zilla controller can be set to give you 1000+ motor amps for
>>neck-snapping
>>accelleration, but limit battery current to 250 amps for long life and good
>>range. The side effect is that performance at high speed is limited; you
>>have to climb hills slower, and it accellerates worse at high speeds.
>>
>>John Wayland has hit on the "magic" formula for impressing people with his
>>EVs. Gorgeous paint jobs, immaculately restored interiors, powerful
>>stereos,
>>and car-show-quality construction and detailing make his EVs
>>*very* impressive. But none of these things prevent you from having a
>>completely mundane, normal-performing daily driver.
>>
>>Now for the wife-performance factors: Find out what *she* looks for in a
>>great car. If she's like mine, she wants silent operation, smooth riding,
>>and very easy to drive (no shifting, power steering and brakes, power
>>everything, etc.). No funny meters or switches or other gadgets to mess
>>with.
>>
>>These are easy on an EV. They are naturally quiet. Even with a manual
>>transmission, you can provide it with electric reverse she can just leave
>>it
>>in one gear all the time. You can add power steering and brakes. An
>>impressive stereo is a great touch. Loud is fine (to impress others), but
>>she may be more interested in a satellite radio or MP3 player.
>>
>>Extra convenience features that you can't get on normal cars are a big
>>plus.
>>For instance, she never has to go to a gas station. The heater and air
>>conditioner can be set up to run even when the car is parked, so she can
>>come out to a comfortable car in the heat or summer or dead of winter.
>>--
>>If you would not be forgotten
>>When your body's dead and rotten
>>Then write of great deeds worth the reading Or do the great deeds worth
>>repeating
>> -- Ben Franklin, Poor Richard's Almanac
>>--
>>Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
>>
>
--- End Message ---
--- Begin Message ---
Ryan Bohm wrote:
> Where do you find a 100 watt resistor?
That's easy; they are made by many manufacturers. Just look in any
catalog that carries IRC, Ohmite, Ward-Leonard, Clarostat, Dale, etc.
You can also use anything with a heating element that happens to be
about the right value (hotplate, toaster, etc.).
> I assume it doesn't need to be rated at a full 100 watts since you
> are switching it off pretty quickly.
Correct. Even a 10 watt resistor would survive 1 second at 100 watts.
But resistors are so cheap that you might as well use a higher wattage
one anyway. A 20-watt resistor is only the size of your little finger,
and costs under $5.00.
> But could you elaborate a little on this idea Lee?
You would need a pair of contactors with contacts rated for the
appropriate DC voltage and current. One switches the motor and resistor
on (starting contactor); the other shorts the resistor (run contactor).
To start the motor, close the start contactor; wait a second (or however
long it takes for the motor to come up to speed), then close the run
contactor.
The time delay can be as simple as an RC network across the run
contactor's coil. For instance, if the contactor has a 100 ohm coil,
power it with a 10 ohm resistor in series and a 100,000uF 16vdc
capacitor across the coil for a 1-second delay. Simple as dirt, though
it's a big capacitor.
Or, power the run contactor's coil with a MOSFET transistor. The same
sort of RC network can be used to drive the gate of the MOSFET, but now
the R can be 1000 times larger (100k) and the C 1000 times smaller
(100uF) for the same delay. Use a "logic" MOSFET that turns on with 5v
at the gate, and split the resistor into two 200k; one from input to
gate, the other in parallel with the capacitor to discharge it when you
turn off.
Include fuses in case something goes wrong. Put a thermal switch on the
resistor to turn off both contactors if the resistor overheats (for
example, the motor is stalled or the run contactor fails to pull in).
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Danny Miller wrote:
> But you will never be able to put liquid metal as a semiconductor
> substrate
Sorry; I didn't mean a liquid metal -- I meant a liquid *OR* a metal.
Metals are the best heat conductors, so we use them almost universally
to conduct the heat away from a semiconductor junction. Often, this is
also a current-carrying conductor (like the mounting tab of a power
transistor), so it needs to be there anyway.
If you want or need an insulated connection between the junction and the
heatsink, this insulator necessarily goes between the metal tab and the
heatsink (not between the semiconductor chip and the metal tab). Since
the metal tab is 100 times larger than the semiconductor chip, the heat
is already spread out over 100 times the area. Thus the thermal
resistance of this insulator is not all that important. It's not a big
problem. Having an insulator that is twice as good, or even 10 times
better won't make any big differences in EV controller design.
Re liquid insulators. You use nonconductive liquids, like oil, freon,
butane, CO2, or fluorinert (a special 3M product made for this purpose).
The power semiconductors are sealed in a case which is flooded with the
liquid. Convection or a pump circulates the liquid to transfer heat from
the semiconductors to the heatsink fins. With even a modest flow rate,
the thermal conduction is better than any metal.
If the liquid has a phase change to gas, even faster heat transfer rates
are possible. The liquid wets the semiconductor, heat from the
semiconductor boils it, the gas bubbles rise and bring in fresh liquid,
the hot gas bubbles reach the cooler heatsink surface where they
condense back into liquid and drip back to the semiconductor and the
process repeats. No pumps needed. The most elegant form of this is a
heat pipe, which moves heat so fast it is almost a thermal
superconductor.
> All insulators have a point where they fail and burn.
Yes; but if it is above the point where the semiconductor is already
destroyed it doesn't matter, except as a safety issue.
> Silicone actually burns at a somewhat low temp.
Don't you mean "silicon"? Silicone is something very different. Silicon
(as in the stuff semiconductors are made of) won't burn even at hundreds
of degrees C, far above the point where it is useless as a
semiconductor.
> I don't think any junction can produce enough heat to damage
> diamond without first burning itself up so this should not be
> a factor.
My concern with the insulator burning is in case of an arc-over. In
dirty environments, you can get water or crud on the insulator's surface
between the electrically "hot" semiconductor and its electrically
grounded heatsink. High voltage can arc over thru this path. If the
insulator can melt or is combustible, it can catch fire or carbonize to
form a conductive. Now you have a SERIOUS problem!
So in high power applications, you don't see cheap plastics as the
thermal insulators. We use aluminum oxide, fiberglass, mica, BeO, and
other highly inert materials.
> Heat sinks can be made smaller if the total junction-to-sink impedance
> is lower. Note the surge capabilities, which involve how much thermal
> mass is on the junction and case side of the system, will be far
> higher.
It all depends on how much of the total thermal resistance comes from
the insulator, and how much from the heatsink itself. In my designs, the
insulator's thermal resistance is already trivial with common, everyday
materials.
For example, you generally don't want a touchable heatsink to be over
140 deg.F = 60 deg.C. You don't want your semiconductor junction to be
over 100 deg.C for reasonable life. That allows for a 40 deg.C
difference between junction and heatsink.
Suppose you're mounting a TO-247 transistor. It has a thermal resistance
of 0.7 deg.C/watt from junction to case. But even an old greased mica
insulator has a thermal resistance of 0.3 deg.C/watt. Suppose we used
it; then the total resistance is 0.7+0.3 = 1 deg.C/watt. For a 40 deg.C
temperature difference, that transistor can dissipate P = 40 deg.C / 1
deg.C/w = 40 watts.
Suppose we had a magic perfect insulator with zero thermal resistance.
The power we could dissipate in the transistor only increases to P = 40
deg.C / 0.7 deg.C/w = 57 watts.
Now, there are probably designers that would kill for those extra 17
watts. But most applications won't be willing to pay for diamonds to
make a small improvement.
> Really the big difference is that a single package can carry craploads
> of power, which has many benefits over several packages spread out over
> the same heat sink.
We already do this. We've had single-chip power devices that can handle
1000 volts at 1000 amps for over 30 years (SCRs and diodes in hockey
puck cases, for example).
Many modern designers *like* the idea of using dozens or hundreds of
cheap tiny devices rather than a few large devices. Sure, it adds labor
cost -- but they'll build it in China. Sure, it lowers reliability --
but who cares if it still works in a few years.
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Ryan Bohm wrote:
> Is it better on my batteries to charge them whenever I have the
> opportunity, or wait until they get at least 10% discharged?
It depends on your charger. If it tends to overcharge, then you are
doing more harm than good by recharging after pulling only 10% of your
charge out. If it tends to undercharge, do you have some sort of
balancing or regulating system to keep the batteries in balance?
But both of these are small problems. A battery at 90% SOC is
essentially fully charged. It can sit for weeks without a problem. I
wouldn't worry about charging it unless it was going to sit that way for
a month or more.
Likewise, if you can charge it a bit without overcharging, and have a
balancing system to keep them all in balance, you might as well go ahead
and charge.
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
> Hi Don and Jerry,
> Well dont want to but I will probably have to go with this van for the vending
because of the way its been set up. I need to quickly get inside the cargo area
for drinks and snacks while standing up inside the van (thats where the hi top
is a lifesaver. On the other hand if a large shell could really be purchased
for an S-10 pickup maybe it would work but it would have to tall as well as
wide enough to acomodate the operator, snack and- drink bins. Where can shells
like that be found? Would like to check into it. My 4 day a week route goes
about 60 miles, 50 miles 40 miles and 45 miles including the trip to and from
home. Half of that is interstate driving. I try to stay at 50 mph to save gas -
it increases 3 mpg from 70 mph. Plan to charge the van for 8 hours from a
120VAC 15A outlet while working at my full time job. Will try and get the
weight again. The bathroom scale got smashed.
> Randy
You're looking at a pretty large pack to get 40-60mi, even if only 20-30mi of
that is at a rather slow 50mph - a NiCd pack at 300V/100Ah (and >$20K) might be
enough, though! How much do you plan on spending?
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
> What is the baud rate from the E-meter?
9600 baud
> Also, as I recall, it does TTL level outputs (0-5V) rather than proper
> RS-232, correct?
No, it is real RS-232 levels. It swings between +10v and -10v no-load.
> Do I need to send anything to it to get it started, or does it
> just output data constantly?
It sends constantly. It ignores any data received, so there is no point
to even hooking up the receive data wire.
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Pestka, Dennis J wrote:
> I'm guessing that after conversion, "less batteries", I will be in
> the 1950# range. A pack of 20 T-105's will add 1220# bringing total
> weight to 3170#. If I go with sealed batteries, I can reduce that
> weight significantly. 13 Optima's = 2535#.
>
> This 635# reduction in weight and higher voltage will also make
> a difference in how this vehicle performs.
>
> The million dollar question is, will it give me the range I desire,
> ~20 mile range most of the time, with a 30 mile range on occasion,
> and not kill my pack in a short period of time.
Range is all about pounds of batteries. To get an X-mile range will
require Y pounds of lead-acid batteries. It doesn't matter what the pack
voltage is, and it doesn't matter what type of battery you use (flooded,
sealed AGM, etc.).
Say you want a 20-mile range to be 50% discharge. The truck will use
about 300 watthours per mile if driven conservatively. 20 miles x
300wh/mile = 6000 watthours.
Lead-acid batteries deliver about 12 watthours per pound. 6000wh /
12wh/# = 500 pounds. If we want that 20-mile drive to use only 50% of
your charger, then you need 1000 pounds of batteries. Optimas or
floodeds; it doesn't matter for range.
6v floodeds weigh about 62#, so 1000# of them is 16 batteries. That
makes a 96v system. Since they are good for about 500 amps peak, your
peak power is 96v x 500a = 48kw or about 48 horsepower.
Optimas weigh about 45#, so 1000# of them is 22 batteries. All in series
is 264v, which is pretty high for a first EV. Wired in two parallel
strings of 11 will give you 132v which is quite reasonable. Each Optima
is also good for 500 amps; the two strings in parallel give you 132v x
500a x 2 = 132kw or about 132 horsepower. That's considerably more
power, if your motor and controller are up to it.
> After spending years with the flooded batteries with my tractors,
> I also must admit I'm really interested in trying something new.
> The sealed battery features of a clean, maintenance free
> installation sounds very tempting.
Yes, it is. But you will pay over twice as much for batteries, and will
need a more expensive charging system. Plus, to make use of the extra
power, you will need to spend more for your motor and controller.
You pays your money, and takes your choice :-)
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hi All,
Thank you for the advice. It is good to get a lot of
input. I called the DMV in Sacramento, luckily I was
only on hold for 10 minutes. When I got through I
mentioned that this was an Electric Vehicle, got put
on hold a few more times and the operator said, "the
vehicle type is marked E and the local DMV must have
made an error" so she recommended that I send the
paper work directly to them. I guess the Santa Clara
DMV did one service in that they marked the vehicle
down as electric. I also have the "Verification of
Vehicle" that has remarks about it being electric and
zero emissions. So I will take the advice of this
operator and the List suggestion of writing a letter
contesting the "Letter of refusal" (I'll take
suggestions on the wording of this since I don't speak
legal-ise).
I'm not sure the drama is over but I did get a good
response from Sacramento.
Thanks,
Rex
--- Neon John <[EMAIL PROTECTED]> wrote:
> On Tue, 26 Jul 2005 07:52:00 -0500, "ohnojoe"
> <[EMAIL PROTECTED]>
> wrote:
>
> >If all fails, visit another DMV.
> >I'd mess with odometer reading as a vary last
> resort.
> >AS someone suggested, you can always say that the
> odomerer
> >itself is new but the vehicle is not so new.
> >They are the ones who made these stupid regulations
> >so difficult, so you play their game too.
>
> I suggest not falsifying the odo reading. Thanks to
> the antics of
> people in my town here(Two "60 minutes visits",
> federal investigation,
> dozens sent off to Club Fed in Atlanta, etc), odo
> tampering/rollback/falsifying is now a federal
> felony. Everything else
> that's been discussed of working around the law
> (stupid, IMO, since
> he's in the right in the first place) are minor
> state misdemeanors. I
> don't think anyone wants to risk a felony.
>
> Just call the state, get it straightened out and do
> it right. The fix
> is probably a phone call away.
>
> John
> ---
> John De Armond
> See my website for my current email address
> http://www.johngsbbq.com
> Cleveland, Occupied TN
>
>
____________________________________________________
Start your day with Yahoo! - make it your home page
http://www.yahoo.com/r/hs
--- End Message ---
--- Begin Message ---
I have found that in the Los Angeles area, if you want
to register something different, take it to the Santa
Monica DMV. The city has a high concentration of
electric cars and was the first to put in a solar
powered electric car charging station. Seven stalls no
less. I don't know where it is now. it has been moved
do to changes in the streets going through the area.
Gadget
--- James Jarrett <[EMAIL PROTECTED]>
wrote:
> On Mon, 2005-07-25 at 17:59, Grannes, Dean wrote:
> > Rex,
> >
> > My experience with the DMV is that in ambiguous or
> out-of-the-ordinary
> > cases (especially with EVs), you'll get different
> answers from different
> > people. Keep trying until you get the answer you
> want.
>
> This can not be stressed enough. When I bought my
> Henney Kilowatt, the
> owner sent me the title. Well his kid had scribbled
> on the title
> sheet. Nothing major, it wasn't really defaced or
> illegilbe or anthing
> like that, but there was some scribbling on the
> back.
>
> I had the vehicle inspector in Union County NC
> (where I lived at the
> time) check over the car and the title and he said,
> no problem, just use
> that.
>
> Took it to the Mecklenburg county DMV (near where I
> work) and they said
> "No way, that's been defaced, you gotta get this
> form filled out by the
> previous owner, then he needs to file for a new
> title, then..."
>
> It was going to be murder. On a lark I took it to
> the Stanly County DMV
> (where I owned some land and am *NOW* living) and
> they had no problem,
> just took care of it.
>
> So just remember where the DMV is concerned NO just
> means "not here" not
> necessarily, no.
>
> James
>
>
visit my website at www.reverendgadget.com
--- End Message ---
--- Begin Message ---
I am not a lawyer! But, since California is insisting that this is a new
vehicle (solely based on it's odometer
reading), then I would check to see if there are currently any state incentives
for the purchase of a new EV, and
apply for them.
--
Stay Charged!
Hump
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Rex Allison
> Sent: Tuesday, July 26, 2005 12:59 PM
> To: [email protected]
> Subject: Re: Electric Vehicle Help - Thanks for the Advice
>
> Hi All,
> Thank you for the advice. It is good to get a lot of input. I called the DMV
> in Sacramento, luckily I was only on hold for 10 minutes. When I got through
> I mentioned that this was an Electric Vehicle, got put on hold a few more
> times and the operator said, "the vehicle type is marked E and the local DMV
> must have made an error" so she recommended that I send the paper work
> directly to them. I guess the Santa Clara DMV did one service in that they
> marked the vehicle down as electric. I also have the "Verification of
> Vehicle" that has remarks about it being electric and zero emissions. So I
> will take the advice of this operator and the List suggestion of writing a
> letter contesting the "Letter of refusal" (I'll take suggestions on the
> wording of this since I don't speak legal-ise).
> I'm not sure the drama is over but I did get a good response from
> Sacramento.
> Thanks,
> Rex
--- End Message ---
--- Begin Message ---
> The most important thing to realize is that the Emeter's signal ground
> on the serial port is tied to the pack negative.
I did remember that, but it's not going to be much of an issue.
The system I'm working with is supposed to draw less than 40ma. I was
planning on connecting it to the 12v supply to the E-meter. Heck I could
probably power it from one of the E-meter's serial port control signals.
--- End Message ---
--- Begin Message ---
Great. Thanks everyone for your help.
Cheers.
>> I forgot to ask....
>>
>> What is the baud rate from the E-meter?
> 9600 N,8,1 no flow control.
>
>> Also, as I recall, it does TTL level outputs (0-5V) rather than proper
>> RS-232, correct?
>
> Nope, hook it right to a laptop.
>
>>
>> Do I need to send anything to it to get it started, or does it just
>> output
>> data constantly?
>
> Just outputs constantly
>
>>
>> Thanks again.
>>
>
> Chris
>
>
--- End Message ---
--- Begin Message ---
Chris Buresh wrote:
>
> What type of considerations need to be made for winter driving? How long can
> batteries sit in 20F weather before freezing? I most likely will store the
> vehicle to protect the structure. How do I keep the batteries alive in my
> cold garage?
Cold storage is no problem. The lower the temperature, the slower the
self discharge rate and the longer it can sit without charging.
The freezing point for a lead-acid battery depends on its state of
charge. It is approximately
-60 deg.F at 100% SOC (specific gravity over 1.250)
-15 deg.F at 50% SOC (specific gravity over 1.200)
+20 deg.F at 0% SOC (specific gravity over 1.100)
The real problem with cold is that it slows down the charging and
discharging reactions. It takes much longer to charge a cold battery;
you need to charge it at a higher voltage, and it will draw less
current. If you try to drive, the voltage sag will be worse and you
can't draw nearly as much current.
If you expect to drive your EV in winter, put the batteries in an
insulated box, and provide a heater.
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I think the key is to take a vigorous interest in the pack. Someone
on this list referred to it as "the art of battery husbandry", and
that's not too far off the mark. Taking care of batteries, floodeds
in particular, has a lot in common with caring for a pet. (see Lee
Hart's great essay on battery maintenance
http://www.sheer.us/ev/lee.html)
Wire them up carefully and using the right connectors and crimping
method (if yours is a DC project, that's a lot of amps that are
passing through those wires).
Use the right charger for your battery chemistry. Monitor your
charging voltages to make sure you're reaching, but not exceeding your
batteries acceptance voltage. Follow your manufacturers guidelines.
Top them off at every opportunity. And if you do decide to run them
to a low percentage of charge, be aware that you're reducing the
number of cycles you're going to get from that pack.
And, like Lee wrote, feed them (water) and exercise them. When I get
back from a vacation, my pack is sluggish, but after two days of
driving it perks up.
I have over 7K miles on my first pack, with one (probably bad from the
start) module replaced, and one more soon (acid leaking from post). I
haven't noticed any degradation in range. I plan to reach at least
10K.
Richard Kelly
On 7/25/05, Ken Albright cfken-at-yahoo.com |vehicle/1.0-Allow|
<...> wrote:
> Hello,
>
> I'm new to the list and currently shopping for the
> donor vehicle for my ev project - more on that later.
>
> However, in the email today was a comment that is a
> bit off-putting to a newbie. Something to the effect
> that everyone fries their first battery pack. I
> really, really don't want to do that. My wife already
> thinks this is a crazy idea and if I kill $2k in
> batteries, she'll probably kill me. Please, someone
> reassure me that with proper precautions I can charge
> the battery pack without frying them. Then tell me
> what those precautions are.
>
> Great list.
>
> Ken Albright
> Columbia, MO
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
>
--- End Message ---
