EV Digest 5220
Topics covered in this issue include:
1) Re: ownerless car?
by Neon John <[EMAIL PROTECTED]>
2) Re: Rudman Reg question
by "Roland Wiench" <[EMAIL PROTECTED]>
3) Re: Newbie question: Multiple cheap motors to drive a vehicle
by Lee Hart <[EMAIL PROTECTED]>
4) Re: dc converter disconnect
by Lee Hart <[EMAIL PROTECTED]>
5) Re: Rudman Reg question
by "Rich Rudman" <[EMAIL PROTECTED]>
6) RE: Rudman Reg question
by "Myles Twete" <[EMAIL PROTECTED]>
7) RE: First week's impression of my conversion.
by "Roger Stockton" <[EMAIL PROTECTED]>
8) 56% electrical eff. from 250kw fuel cell/60kw microturbine combo
by Brian Cole <[EMAIL PROTECTED]>
9) RE: Need Idiot's Guidance to PFC20 & Wet Cell Batteries
by "Roger Stockton" <[EMAIL PROTECTED]>
10) RE: Rudman Reg question
by "Roger Stockton" <[EMAIL PROTECTED]>
11) Battery Regulator questions
by Eric Poulsen <[EMAIL PROTECTED]>
12) Re: E-Meter confusion
by Lee Hart <[EMAIL PROTECTED]>
13) Re: PMC 21 repair - resistors burn out
by kluge <[EMAIL PROTECTED]>
14) Re: dc converter disconnect
by Eric Poulsen <[EMAIL PROTECTED]>
15) RE: E-Meter confusion
by "Roger Stockton" <[EMAIL PROTECTED]>
16) Re: Mk3s expense/benifits
by "Philippe Borges" <[EMAIL PROTECTED]>
17) Re: Vacuum pumps
by [EMAIL PROTECTED] (Dana Havranek)
18) Re: Rudman Reg question
by "Rich Rudman" <[EMAIL PROTECTED]>
19) RE: Mk3s expense/benifits
by "Roger Stockton" <[EMAIL PROTECTED]>
20) Re: Battery Regulator questions
by "Rich Rudman" <[EMAIL PROTECTED]>
21) new "This New Car" Radio Show now on-line (blurb added)
by M Bianchi <[EMAIL PROTECTED]>
22) RE: Revived and free batteries?
by "Myles Twete" <[EMAIL PROTECTED]>
--- Begin Message ---
Of course, you could just run the vehicle through a state such as TN
or Al that does not require a title on 10-year-or-older vehicles but
will issue one on request. A bill-of-sale is all that is needed. All
you need to do is sell the vehicle to a resident of those states and
then buy it right back after the title arrives. There is no physical
inspection so the vehicle doesn't even have to be here.
John
On Tue, 28 Feb 2006 09:30:31 -0800, Eric Poulsen <[EMAIL PROTECTED]>
wrote:
>Lee Hart wrote:
>> The state's main concern is to prevent stolen cars from being easily
>> re-titled. In the states where I have lived, this means you submit the
>> serial numbers of the engine, transmission, body, and other major parts,
>> so they can check their database to see if these parts have ever been
>> part of a car that was stolen.
>>
>FWIW, this is pretty much the procedure in California, as well. You'll
>have to have receipts for the major components (engine, tranny, etc) of
>a "custom built" vehicle. From what I've heard (mostly from the custom
>chopper guys), this is pretty painless if you have your ducks in a row.
>California has a lot of custom vehicles, so it might be a bit easier
>than other states.
>
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
--- End Message ---
--- Begin Message ---
Hello Myles,
You are off 1 volt. The Regs operate in a range of 14.75 to 14.82 volts
with a average of 14.8 volts. You can adjust this voltage.
See http://www.manzantamicro.com/
Roland
----- Original Message -----
From: "Myles Twete" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, February 28, 2006 12:02 PM
Subject: Rudman Reg question
> As I understand it, the Rudman Regs initiate bypass at 13.8v.
> This is at the high end of a typical Hawker float charge voltage
> (13.5-13.8)
> and well below the low end of the fast charge target (14.7-15.0v).
>
> So how are these regs supposed to be good for racing applications where
> maximum high rate and capacity in recharge is the goal?
>
> Thanks.
>
> -Myles Twete, Portland, Or.
>
--- End Message ---
--- Begin Message ---
ziperle wrote:
> I just read the EV article in Make magazine and it got me thinking
> real hard about doing an EV conversion.
Great!
> There is a picture of a Datsun with 3 motors installed that was
> converted by Tom True and Don Crabtree. What is the advantage of
> doing this?
Mostly, it's done for expediency -- when you can't get the motor you
really want, or it doesn't fit.
> Is there any sense in doing cheap redundant motors and batteries?
Sure, there are sometimes good sound reasons why many smaller devices
are better than one big one.
All things being equal, a bigger motor or battery is more efficient,
more compact, more economical, and more powerful than a collection of
smaller ones built exactly the same way.
But in the "real world", there are often practical limitations:
1. A single large one might be of an inconvenient size or weight.
Using several smaller ones will physically fit better in the
available space.
2. The smaller ones are sold in larger quantities, and so benefit
from "economies of scale". You get a better price for them because
the manufacturer sells more of them.
3. Having multiple motors (or batteries) lets you arrange them in
various series or parallel combinations, in effect changing their
voltage.
4. Redundancy. Having multiple motors means you might still be able
to drive even if one breaks.
5. Motor per wheel. You might want to use one motor per wheel, to
eliminate the differential to save size and weight.
> Crazy thought but EVs offer the possibility of driving the vehicle
> with redundant systems.
We certainly do this with the batteries. A single large cell is
possible, but the economies of scale mean it is very rarely done.
> I found some DC treadmill motors cheap and in the 1-2.5hp range...
> 2.25hp @ 260VDC and 5 amps, weighs 14 lbs... I know this sounds wimpy
> compared to the Advanced DC or ETek motors but does this make any
> sense for an entry level conversion?
Well, 260v x 5a = 1300 watts in. 2.25hp x 746w/hp = 1678 watts out.
Since you can't get more power out than you put in, these must be
marketing lies. A real motor of this size will be around 75% efficient.
That means 260v at 5a produces about 1.3 horsepower.
Ok, suppose you used 10 of these motors. They weigh 140 lbs, and 260v at
50a gives you 13hp at 75% efficiency. A single equivalent motor would
weigh more like 100 lbs and be 80% efficient.
So, you could do it; it would work and only add a little weight and lose
a little efficiency. Whether it's worth doing depends on what you have
to pay for the motors, and how hard it is to couple them all together.
> Also, does anyone have experience with controllers? Is it easier to
> control higher voltage or amperage? I would think that higher voltage
> has the advantage of permitting smaller gauge wire and maybe better
> efficiency when it comes to voltage drops from impedance and
> resistance that are inherent in batteries, motors and controller
> components.
As you go higher in either voltage or current, the problems get
progressively more difficult. 12v to 24v is trivial; 24v to 48v is easy,
48v to 96v is harder, 96v to 196v is even harder, and 196v to 392v has
some very serious arcing and safety challenges. Likewise with current.
So as a rule, most EV designs aim to have the maximum voltage and
current about the same. A golf cart uses 36v at 75a; a small car uses
96v at 100a; a sports car uses 300v at 200a, etc. To increase power,
it's easier and cheaper to increase whichever one is lower (the "easy"
one; voltage or current, as the case may be). When that starts to get
hard, increase the other one.
--
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 ---
Tim Wong wrote:
> My converter input voltage is nom 108V, and my converter draws about
> 7A max. For the fuse, the 3AB is 125VDC... my car is something like
> 12A at 130VDC, I think.
For a 7a load, I'd use a 15a fuse. A 3AB (15a, 125vdc) would be fine;
fuse ratings are not precise, and you are close enough.
> Also, should it be slow blow or fast blow?
Most DC/DCs are really just relabelled AC power supplies, and so have a
huge input filter capacitor (so they can supply power during the zero
crossings of the AC line). If you connect them straight across a big
battery with nothing but a switch or relay, the capacitors try to charge
*instantly*. This huge inrush current will trip a fast-blow fuse. The
3AB and ABC are fast-blow types, so you shouldn't do this.
The right way to do it is with some kind of precharge circuit. This can
be as simple as a series inrush limiter (a little part that looks like a
disk ceramic capacitor). They limit the inrush to something like 10-30
amps. The DC/DC might have one built-in already. See if its
specifications say anything about "maximum inrush current".
Or, you can connect a resistor in series with the input to precharge the
capacitor, and then short out this resistor in a second or so once the
output is active.
> I am looking at the bussman HFA type.
This is good. It's rated for the voltage and current, and has a phenolic
body so it won't burn or melt. It's waterproof to prevent corrosion.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I set them to 14.8 here They are adjustable from about 13.9 to 16.00 volts
So the extra Volt is what you missed.
Also the Mk3s are programamble, basicly from the poin the wake up and sign
on to 20 volts. Quite a large range.
I have a MK3 in the programmer under my keyboard right now.. gonna fry it as
a #1 on the Buss SN# 25.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Myles Twete" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, February 28, 2006 11:02 AM
Subject: Rudman Reg question
> As I understand it, the Rudman Regs initiate bypass at 13.8v.
> This is at the high end of a typical Hawker float charge voltage
(13.5-13.8)
> and well below the low end of the fast charge target (14.7-15.0v).
>
> So how are these regs supposed to be good for racing applications where
> maximum high rate and capacity in recharge is the goal?
>
> Thanks.
>
> -Myles Twete, Portland, Or.
>
--- End Message ---
--- Begin Message ---
Thanks for the correction Lee.
I guess I didn't navigate far enough through the Manzanita regs operations
page.
The first operations page indicates 13.8v:
http://www.manzanitamicro.com/op1.htm .
I do see the adjustment descriptions here (
http://www.manzanitamicro.com/inst1.htm ) indicating 'bouncing around'
betweein 14.75-14.82v.
Another question: so, is it okay to leave the batteries on charge with these
regulators set to the nominal preset voltage, say, for a day beyond being
full as long as the regs can handle it? Or will AGMs hate being kept at
that high of a voltage for an extended time?
-Myles
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Roland Wiench
> Sent: Tuesday, February 28, 2006 11:59 AM
> To: [email protected]
> Subject: Re: Rudman Reg question
>
>
> Hello Myles,
>
> You are off 1 volt. The Regs operate in a range of 14.75 to
> 14.82 volts
> with a average of 14.8 volts. You can adjust this voltage.
>
> See http://www.manzantamicro.com/
>
> Roland
>
>
> ----- Original Message -----
> From: "Myles Twete" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Tuesday, February 28, 2006 12:02 PM
> Subject: Rudman Reg question
>
>
> > As I understand it, the Rudman Regs initiate bypass at 13.8v.
> > This is at the high end of a typical Hawker float charge voltage
> > (13.5-13.8)
> > and well below the low end of the fast charge target (14.7-15.0v).
> >
> > So how are these regs supposed to be good for racing
> applications where
> > maximum high rate and capacity in recharge is the goal?
> >
> > Thanks.
> >
> > -Myles Twete, Portland, Or.
> >
>
--- End Message ---
--- Begin Message ---
Jeff Shanab [mailto:[EMAIL PROTECTED] wrote:
> a Link1000 works, but a link 10 is way better for 3 reasons.
> It has a way of scaleing so the decimal looks right, it can
> go to 1000amps with a 1000amp 100mv shunt and display
> correctly and it has rs232.
Are you sure about this? The E-Meters (Link-10s) I've used saturate at
-511A when the discharge current exceeds 500A. A 1000A 100mV and 500A
50mV shunt look exactly the same to the E-Meter.
I have heard that you may be [have been?] able to get a version of the
E-Meter/Link-10 with software that allows it to display currents in
excess of 511A, but as far as I know the standard units don't do this.
> I need to ask the list for some ideas
> on how to achieve waterproof EV. It is raining today and my
> drive home had me worrying. I have EXIDE Orbitals and have
> been looking thru album but havent found an example of
> orbitals under the hood with reg's.
Look at Al Godfrey's Porsche 914 conversion (now owned by John Littauer)
in the EV Album:
<http://www.austinev.org/evalbum/050c.jpg>
He used Optimas, and had his regs all mounted remotely in a box in the
trunk (the box to the left of the grey "high voltage" box in the
picture; the neat row of yellow/orange-ish rectangles is are the load
resistors (nice aluminum finned power resistors)). I remember Rich
looking at the installation and remarking to Al that this was the way it
should be done (and I think something to the effect that this was the
only example he knew of (at that time) doing it correctly).
My understanding is that when you use remote loads, you remove/disable
the onboard load. The load *resistor* is not what the onboard
thermistor is intended to protect; it is (mostly) intended to keep the
onboard FET from dying; since the FET remains onboard even with a remote
load, the thermistor can still do its job. Of course, the heat of the
onbard load resistor is also sensed (when it is used), but the resistor
itself can survive quite high temps, and when you remote the load
resistors, you can provide a cooling fan to keep them cool.
If you remote the loads, then you can enclose the regs in waterproof
boxes, etc. to protect them from the elements. You will have a pair of
wires from each reg to its remote load, and will likely have each reg in
its own individual box.
If you remote the regs, then you should use kelvin sensing of the
voltage, which means 4 wires between each reg and its battery. However,
now you can bundle multiple regs into a single enclosure to protect them
from the elements, and use a single fan (per enclosure) to keep the regs
cool.
My personal preference would be to remote the regs, as this would allow
mounting them so that all LEDs are visible in a single location rather
than scattered around the vehicle and possible hidden inside of battery
boxes. Follow Manzanita Micro's guidelines for sizing the wire between
each reg and its battery, bearing in mind that the voltage sense
connections can be much lighter guage than the load connections since
they don't carry any current. I would either use a heavy-ish guage
2-conductor and a light-guage 2-conductor cable between each reg and its
battery to make the 4 connections, or a single multi (e.g. 6-8
conductor) cable with one pair reserved for voltage sense and the rest
of the wires connected to form a pair with sufficient current capacity
for the load connections.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
http://www.cleanedge.com/story.php?nID=3983
http://www.fuelcellenergy.com/site/products/hybrid.html
FuelCell Energy mated it's 250kw Direct Fuel Cell with
a 60kw Capstone Microturbine. The power plant ran at
56% electrical efficiency for 800 continuous hours of
initial testing. That's a record in the sub-megawatt
powerplant class, and compares favorably with
state-of-the-art combined cycle gas turbine plants
1,000 times more powerful. Goals for future
multi-megawatt plants are 70% or better electrical
efficiency. Long-term, net electrical efficiencies
near 80% are believed possible for large capacity
power plants.
Interesting palm-size microturbine M-DOT mated to a 1
or 2 kw alternator for a DARPA project around 1998.
http://www.m-dot.com/page8.html
http://www.rcuniverse.com/magazine/article_display.cfm?article_id=166
http://www.darpa.mil/darpatech99/Presentations/dsopdf/dsowax2.pdf
The above url is a long pdf that I got by doing a
google search on "steven g. wax" darpa m-dot turbine
The turbine-alternator info is about 1/2 way down.
-brian
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
David McWethy [mailto:[EMAIL PROTECTED] wrote:
> I am curious about temperature and charging voltage. If it
> is 40 degrees, as it is here tonight, are you saying I need
> to charge at a higher voltage than if it were 78?
First, what is important is *battery* temperature, not ambient
temperature. Ambient (air) temperature can change fairly quickly, but
batteries tend to change temperature more slowly, and heat up internally
when charge or discharge current is flowing. As a result, it is likely
that if you are charging and discharging the batteries daily they
probably remain somewhat warmer than ambient, or at least nearer to the
average daily temperature than to the peak daytime or minimum nighttime
temperature.
Otherwise, yes, if the batteries are cool then the charge voltage should
be increased, and if they are warm it should be decreased.
The manufacturers usually specify charge voltages at 20C or 25C or 80F
(26.7C). Typically the charge voltage is compensated by about
0.005V/cell per degree C away from this temperature. For those more
comfortable working in terms of Fahrenheit, this is 0.028V/cell per 10F
or 0.0028V/cell per degree F.
So, in your example, if using Trojan floodeds at 78F, I would charge to
2.43V/cell. At 40F, I would charge to: 2.43 + 0.0028 * (78-40) = 2.43 +
0.1064 = 2.54V/cell.
> I have a 120V system and a primitive charger.
For a 120V system (60 cells), the 78F charge voltage would be 146V, and
the 40F voltage would be 152V.
> I am approaching full charge (measured later and temp corrected)
> when my E Meter reads 150V on high charge and maybe 141 on low
> charge. If I don't have excessive boiling, am I overcharging?
> Amps only go to a max initially of about 12.
Regardless of being on high or low charge setting, the voltage you want
to hit remains the same. Note that this voltage is not the maximum
voltage you might see during charge, it is simply the voltage you want
to charge to and hold until the current tapers off to a lowish value (a
few % of the Ah rating, usually). If you perform a constant current
finish to complete the charge, then the voltage during this time will go
higher than the target voltage discussed above.
With flooded batteries, the final word on state of charge is always your
hydrometer: if the s.g. is no longer increasing even if you continue
charging, then the batteries are full. Typically you would expect an
s.g. of at least 1.265 for a fully charged battery in good shape, and
values over 1.275 should be common for newer batteries. If you aren't
boiling excessively or using excessive water, then you probably aren't
overcharging (but could be undercharging), however, "excessive" is
subjective, so it is quite difficult to guage from here.
I would suggest that you let your charger run for a normal charge cycle,
then check the s.g. Then restarg the charger and let it run at a lowish
current (e.g. 5-8A for T105-ish size batteries). Recheck the s.g. every
30 or 60 minutes until you find that they have remained essentially
unchanged for 2-3 readings. Your batteries are now full (you've just
done an equalise charge). If the s.g. was already at this level at the
end of the normal charge, then you could try terminating your normal
charge 15-30 min earlier next time and check to see if the s.g. drops.
Keep decreasing the charge time until the s.g. is lower at the end of
charge. Now you know what the least amount of charge is that you must
provide to fully charge your batteries. You want to charge somewhat
more than this, but not too much. If your water consumption right now
is acceptable to you, then I would just check s.g. to confirm that you
are charging long enough to fully charge, and leave it at that.
Hope this helps,
Roger.
--- End Message ---
--- Begin Message ---
Myles Twete [mailto:[EMAIL PROTECTED] wrote:
> Another question: so, is it okay to leave the batteries on
> charge with these regulators set to the nominal preset
> voltage, say, for a day beyond being full as long as the regs
> can handle it? Or will AGMs hate being kept at that high of
> a voltage for an extended time?
Grid corrosion (and possibly other undesireable effects) are accelerated
when you hold the battery at a higher than normal voltage so you would
not want to leave the batteries at 14.7V any longer than necessary.
Even float voltages (e.g. 13.2-13.8V) are preferably avoided whenever
possible (it is preferable to have the charger periodically restart to
top up the batteries than to leave them on float indefinitely).
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I have a question regarding the bypass-style regulators (like the Rudman
Reg).
I read the functional description, and it says it "bypasses" the
battery. To me, "bypass" means to remove (disconnect) the battery from
the circuit, though clearly that isn't the case.
Seems to me that what the regs do is reach a certain trip voltage, then
they turn on a low impedance transistor which is in series with a
low-ohm high-wattage resistor. These two components are across the
battery terminals, and the battery itself is always wired to the pack.
So if I understand it correctly, the reg intermittently puts a load
across the battery in order to bleed off a bit of the charge. In the
process, the battery voltage is reduced slightly for a short time after
the load is removed. When the battery reaches the trip voltage again,
the reg cuts the load in again.
Is this correct?
Is the load on-period a fixed amount of time, or by battery voltage drop ?
Is the on-period also affected by the temp of the reg / resistor / heat
sink?
Does "(micro)cycling" the battery when it's full have any weird /
adverse / serendipitical affect on the battery?
--- End Message ---
--- Begin Message ---
Roger Stockton wrote:
> One other gotcha is that the E-Meter ignores currents of about 0.1A
> or less; it will indicate them on the amps display, but will not
> update the Ah count (when used with a stock 500A/50mV shunt).
Right. I think they do this to ignore small offset errors. Without this
"feature", if the meter thinks it sees some tiny voltage when there is
in fact 0 volts on the shunt, it would accumulate this error in its
amphour reading.
I don't know what the limit is, but it must be less than 0.1amp. When it
is below -20 deg.F in Minnesota, my E-meter Ah s-l-o-w-l-y counts down,
about 0.2ah per day. That would imply a discharge current of 0.008 amps.
In fact, this is *closer* to correct than the "0 amps" it normally
assumes, because I power the E-meter from the pack with a little DC/DC
converter that draws about 7 ma continuously.
>> +9ah keeps counting up if you keep charging
>> Park: 0ah when you stop charging, the E-meter resets the
>> Ah counter again to zero
> Actually, the E-Meter resets the Ah count to 0Ah only after there is
> a discharge current in excess of some nominal amount (a few amps I
> think, but I don't recall the actual value offhand); it will not
> reset to 0Ah when the charge current stops, as this example might
> seem to imply.
My impression is that it clears out the positive amphours when it sees
the *amphour* counter fall. It could be 10 amps for 1 second, or 0.1 amp
for an hour. So when you stop charging, sooner or later it resets the
positive amphours to zero.
> For testing, I find it easiest simply to use the logged amps, volts,
> and temperature data and compute the Ah myself. During testing, the
> discharge and charge currents change slowly enough that accurate Ah
> measurements are possible even with the E-Meter's 1 second reporting
> intervals.
Yes, I do the same. I could use the Volts and KWH to calculate the
amphours, but the Ah is close enough for battery testing.
Also, if you average the 1-second samples from the E-meter, you get
extra resolution. If the actual voltage is (for example) 12.345v, the
E-meter will alternately display 12.30v, 12.35v, 12.30v, 12.35v... If
you average a large number of these samples together, sure enough; you
get 12.345v.
There are two reasons to get so esoteric and nit-picky on this. First,
the E-meter *lies* to you. There are good reasons it does so (like to
ignore offset errors and to automacally correct for battery efficiency),
but for certain purposes you need to know the true values. Second, if
you are trying to build an equivalent to the E-meter, these are the same
problems you will have to deal with!
--
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 ---
kluge wrote:
> there are two 5 watt,
> 3K ohm resisters at the edge of the circuit board which appear to have gotten
> pretty hot; I can't see anything else visually that looks suspect. Are those
> the resistors you're talking about?
David Roden replied:
> Sorry, it's been too long - a dozen or so years - and I don't recall the
details any more. I thought only one resistor went south, but it might have
been two. I had a lot of help on this from a EE friend, who reverse-
engineered the logic board and figured out what the problem was.
> I'd say it can't hurt to chip off the potting compound and try replacing
them.
Since my idea of "reverse engineering" is when the guy driving the train
decides to back up, I guess I don't have too many other options, do I?
Thanks anyway - at least I've got "a" clue to start with now, which is more
than I had before. :-)
Steve
--- End Message ---
--- Begin Message ---
David McWethy wrote:
Why not use a mos fet and small relay to turn the mos fet on or off.
Have the Mos fet on the negative end , a 10v zener for gate to
source to keep gate voltage form going to hi and a 1 meg resistor
form dc to dc input + to relay ( could even us opto coupler here)
from other point of relay to fet gate. you could even put a cap in
parallel with zener to give a slow start up ( save the caps in your
dc to dc converter) .
Steve - I don't question that all of this is good advice. What is it
in English? Just when I think I start to know the language you guys
come up with a "zener". I still don't know what a "mos fet" is , tho
the term is now familiar.
I should have paid attention to this stuff 20 years ago!
Dave
A zener diode is a simple shunt voltage regulator. It's a diode that's
make to have a specific breakdown point for reverse voltages. Typically
you connect a higher voltage to a current limiting resistor that's in
series with the zener that's referenced to your ground, like this:
+12V
|
/
\
/ Current limiting resistor
\
|
+-----------> 5V out
|
__|__/
/ /\
/ \ 5V Zener Diode
----
|
|
|
0V (gnd)
This is only suitable for very low power output.
WRT to the MOSFET (Metal Oxide Semiconductor Field Effect Transistor)
... Well, that's a bit outside the scope of a simple email =) Suffice
it to say it's something of an electrically controlled switch, much like
a regular transistor.
--- End Message ---
--- Begin Message ---
Lee Hart [mailto:[EMAIL PROTECTED] wrote:
> I don't know what the limit is, but it must be less than
> 0.1amp.
I haven't investigated it thoroughly, however, I know that my personal
sample did not accumulate Ah when the amps display (and log) indicated
0.1A for many hours. Someday I may go to the trouble of indepanedantly
monitoring the actual current to see just how low it needs to be before
the E-Meter stops tracking it, but since 0.1A is well below my normal
charge/discharge levels it is a low priority task ;^>
It is a bit suspicious that your sample seems to track your consumption
so accurately (an apparent 0.008A draw with a known 0.007A load due to
the DC/DC). I suspect that if you log the data continuously you might
find that the current reads 0A most of the time and -0.1 or -0.2 every
now and then and this just happnes to result in a small change in Ah
count over a long enough time. Certainly, I would consider it an error
for my software (if it were mine) to not ignore currents that far below
the minimum indicatable 0.1A level.
> My impression is that it clears out the positive amphours
> when it sees the *amphour* counter fall. It could be 10 amps
> for 1 second, or 0.1 amp for an hour. So when you stop
> charging, sooner or later it resets the positive amphours to zero.
Right, this sounds consistent with my experience. I think the key point
is that when the fully charged parameters are met, the E-Meter will jump
abruptly from some non-zero (positive or negative) Ah count to 0 and
then resume counting up, and as soon as enough load is applied to
decrement the Ah count, it will abruptly jump from some positive
end-of-charge value to 0Ah and begin counting down. Both cases result
in a discontinuity in the logged data that must be handled.
> Also, if you average the 1-second samples from the E-meter,
> you get extra resolution. If the actual voltage is (for
> example) 12.345v, the E-meter will alternately display
> 12.30v, 12.35v, 12.30v, 12.35v... If you average a large
> number of these samples together, sure enough; you get 12.345v.
Yes, I also do this. Typically I will average 10 samples during battery
testing since values change slowly anyway.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
34970A at 1200$
http://cgi.ebay.com/AGILENT-34970A-DATA-ACQUISITION-SWITCH-UNIT_W0QQitemZ7572266570QQcategoryZ25402QQrdZ1QQcmdZViewItem
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: "Roger Stockton" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, February 28, 2006 7:41 PM
Subject: RE: Mk3s expense/benifits
> Rich Rudman [mailto:[EMAIL PROTECTED] wrote:
>
> > This looks like what I need to do Cal an quality control
> > on My Reg production line. And could be used for some major
> > upgrading to my Charger power bench.
>
> I think you'll find it indispensible once you try one out. You ought to
> be able to rent one locally to see if you like it before you buy.
>
> > Lets see you get it into a a battery rack...ina REAL EV...
> > Got ya there!!!
>
> Maybe you do, maybe you don't... ;^> Getting a 34970A into an EV
> wouldn't be too bad at all, its only got a footprint of about the size
> of a sheet of letter paper (8.5"x11") and stands about 3-4" tall. It
> can to data acquisition on its own, including firing any of its 4 alarm
> outputs in standalone mode, but you'd need a PC of some sort connected
> if you wanted it to do any real reg functions. No argument that your
> regs are a much easier, cleaner solution!
>
> As it happens, I recently found a screaming deal on an HP3497, the
> rackmount predecessor of the 34970A and bought it for my home lab/EV
> use. I don't see getting that into my EV permanently, but will likely
> have it on a cart in the garage so it can do data acquisition during
> charge and perhaps even some basic regulation duties.
>
> Cheers,
>
> Roger.
>
>
--- End Message ---
--- Begin Message ---
Thanks - Jeff & Michaela
I've been following discussions about isolating vacuum pumps to cut down on
noise -
I suspected it might be a problem.
I started mine up for the first time the other day and confirmed what I
expected.
It's a nice diaphram pump but it's about as loud as my air compressor.
I isolated it O.K. and I can cut down on the exhaust noise, but it's a loser
without a lot of pillows.
I have a cheapo Ford pump that's quieter, but, like Mike from Electro says,
probably not the place to skimp.
Don't have any experience with a rotary vane pumps, but it seems like they
might be quieter.
If anyone is running one of these, I would be interested to hear of their
experience.
Dana
-------------- Original message ----------------------
From: Jeff Shanab <[EMAIL PROTECTED]>
> I found a wabco unit, but discovered they expect oil from the ICE system
> to be avail. I need to look at maybe a tri-lobe like the guys use for
> racing, Originally, A modified ford smog pump. You are on the right
> track, rotary vane or gear or trilobe all should be a lot qieter than a
> single piston.
>
--- End Message ---
--- Begin Message ---
I leave my Mk2B regs on ALL the time, Charger on or EV on or Breaker off.
They live on top of my AGMS until the AGMS die or the Regs need cleaning and
service.
I have some really good examples of enviromental contamination and
Survival...
AGM WANT to be left at high volts.
----- Original Message -----
From: "Myles Twete" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, February 28, 2006 12:45 PM
Subject: RE: Rudman Reg question
> Thanks for the correction Lee.
>
> I guess I didn't navigate far enough through the Manzanita regs operations
> page.
> The first operations page indicates 13.8v:
> http://www.manzanitamicro.com/op1.htm .
> I do see the adjustment descriptions here (
> http://www.manzanitamicro.com/inst1.htm ) indicating 'bouncing around'
> betweein 14.75-14.82v.
>
> Another question: so, is it okay to leave the batteries on charge with
these
> regulators set to the nominal preset voltage, say, for a day beyond being
> full as long as the regs can handle it? Or will AGMs hate being kept at
> that high of a voltage for an extended time?
>
> -Myles
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> > Behalf Of Roland Wiench
> > Sent: Tuesday, February 28, 2006 11:59 AM
> > To: [email protected]
> > Subject: Re: Rudman Reg question
> >
> >
> > Hello Myles,
> >
> > You are off 1 volt. The Regs operate in a range of 14.75 to
> > 14.82 volts
> > with a average of 14.8 volts. You can adjust this voltage.
> >
> > See http://www.manzantamicro.com/
> >
> > Roland
> >
> >
> > ----- Original Message -----
> > From: "Myles Twete" <[EMAIL PROTECTED]>
> > To: <[email protected]>
> > Sent: Tuesday, February 28, 2006 12:02 PM
> > Subject: Rudman Reg question
> >
> >
> > > As I understand it, the Rudman Regs initiate bypass at 13.8v.
> > > This is at the high end of a typical Hawker float charge voltage
> > > (13.5-13.8)
> > > and well below the low end of the fast charge target (14.7-15.0v).
> > >
> > > So how are these regs supposed to be good for racing
> > applications where
> > > maximum high rate and capacity in recharge is the goal?
> > >
> > > Thanks.
> > >
> > > -Myles Twete, Portland, Or.
> > >
> >
>
--- End Message ---
--- Begin Message ---
Philippe Borges [mailto:[EMAIL PROTECTED] wrote:
> 34970A at 1200$
>
> http://cgi.ebay.com/AGILENT-34970A-DATA-ACQUISITION-SWITCH-UNI
> T_W0QQitemZ7572266570QQcategoryZ25402QQrdZ1QQcmd> ZViewItem
Not a bad price, but you can do better:
<http://www.used-line.com/cgi-bin/a_search/b_searchresult.cfm?criteria_1
=34970A&time_frame=1&type=inv&p_n=1>
About US$1200-1250 is pretty much the going price for a refurbished (and
warranted) 34970A from a reputable rental/used equipment house; I
certainly would shy away from paying similar money for one on Ebay when
the seller doesn't provide any description of the item, nor any warranty
info.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Eric Poulsen" <[EMAIL PROTECTED]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, February 28, 2006 1:32 PM
Subject: Battery Regulator questions
> I have a question regarding the bypass-style regulators (like the Rudman
> Reg).
>
> I read the functional description, and it says it "bypasses" the
> battery. To me, "bypass" means to remove (disconnect) the battery from
> the circuit, though clearly that isn't the case.
>
> Seems to me that what the regs do is reach a certain trip voltage, then
> they turn on a low impedance transistor which is in series with a
> low-ohm high-wattage resistor. These two components are across the
> battery terminals, and the battery itself is always wired to the pack.
>
> So if I understand it correctly, the reg intermittently puts a load
> across the battery in order to bleed off a bit of the charge. In the
> process, the battery voltage is reduced slightly for a short time after
> the load is removed. When the battery reaches the trip voltage again,
> the reg cuts the load in again.
>
> Is this correct?
Yes
>
> Is the load on-period a fixed amount of time, or by battery voltage drop ?
> Is the on-period also affected by the temp of the reg / resistor / heat
> sink?
> Does "(micro)cycling" the battery when it's full have any weird /
> adverse / serendipitical affect on the battery?
>
Most AGMS love the micro cycling.. some folks call it pulse charging at the
end of the cycle. I just call it Regging.
Mk2B use voltage and a timer cap to get a minimum cycle rate. Loose
conenctions can screw with this.
I want a 1/2 second pulse. If you over voltage the Reg..drive it harder than
it can regulate back... the Reg will lock full on until it thermals out.
This is supposed to happen at 1 volt over the setpoint.
AKA 15.8 on a Reg set to 14.8. Your results will vary.
Yes the On time varyies by a LOT of things. Size of battery, State of charge
or discharge, current being applied.. temp.. Phase of the Moon....
Digi Regs are set to do a 1/4 sec on then 1/4 off IF every on pulse drops
below the set point. If they can't bring the Volts down they lock on. A bit
more predictable... And can be programmed for other advanced cycling
needs... I haven't done this yet... but I could..
Bypass Let current bypass the battery that the Regulator is across.
Clearly thermalling out also triggers feed back to the charger to Back off
the Amps..
If you don't have a feed back Buss, then you better adjust your charger to
suit or expect some really hot Regs.
Mk2B peak temps are 240 F, the Mk3 are set to 150 F at this moment, I want
just over 212 for production MK3 regs. Hot, Yea REALLY hot, but not so hot
to break transistors or Micros.
Fingers and Body parts are simply State changing temporary heatsinks...
Hopefully the control will keep the Regs from hitting the thermal limits...
Yea Right... a beat up set of Old AGMs and a 10Kw charger, and you will have
a couple that do get extremely hot.
Rich Rudman
Manzanita Micro
--- End Message ---
--- Begin Message ---
ANOTHER episode of "This New Car" is now on-line (MP3 recording) at
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"This New Car" is hosted by Steven Jones-D'Agostino of Best Rate Of Climb in
Worcester, MA, and sponsored exclusively by Westboro Toyota.
--
Mike Bianchi
--- End Message ---
--- Begin Message ---
Victor noted:
> Note I didn't say dead battery, I said totally discharged
> but otherwise undamaged one, with good plates and all insides
> in good shape.
Right...good distinction.
> The trick 1 is to get such revived battery back to original
> capacity, not just make it accept the charge by converting
> water back into the acid and have some terminal voltage on it.
Okay.
> Trick 2 is to get about the same cycle life as if nothing happened.
> I doubt anyone has data how long such battery works compared
> to the "normal" one.
And i won't pursue this either...
> So, Myles, how much of original battery capacity is still there now?
> Ability to run the load for some time now is sure better than
> nothing, but if 17Ah battery now possess, say, solid 3Ah, is the
> reward worth the effort? If you re-gain no more than 50% of capacity,
> it may not; otherwise perhaps it is. Any numbers to share?
Sure, Victor.
I've done one solid cycle on this 12v/17.2ah battery (actually a Yuasa
NP18-12B e.g. http://www.batterywholesale.com/specs/yuasa/NP18-12B.pdf ).
Here's what the first round did after getting it to accept some kind of
decent charge:
Discharge at CC of 4amps (0.23C):
Time Voltage
0 12.59v (no load)
0 12.1 v (4amps)
30min 11.94v
60min 11.73v
98min 11.20v
106m 10.33v
So I got roughly 7.0ah out of the battery on its first decent discharge
after being revived. The spec shows that at 0.23C a new battery is rated at
4hours @ 4amps, or 16a-h.
So, first real test it has hit about 44% of the rated capacity.
Not bad for something I was going to just throw into the recycling.
I just recharged it also:
Time Current ([EMAIL PROTECTED])
0 13amps
10min 10.6a
60min 2.3a
160min 0.2a
Looks like maybe it got as much as 6 or 7ah in bulk....
If interested, I'll run thru the test again and post the results.
-Myles
--- End Message ---
