EV Digest 5479
Topics covered in this issue include:
1) Re: Vacuum courtesy of the mercedes-diesel list.
by Neon John <[EMAIL PROTECTED]>
2) Re: Deka AGM vs. Sanyo D nicad
by [EMAIL PROTECTED] (Brad Baylor)
3) Re: Vacuum courtesy of the mercedes-diesel list.
by James Massey <[EMAIL PROTECTED]>
4) Efficiency of flooded lead acids
by "Robert Chew" <[EMAIL PROTECTED]>
5) Re: [irrelevant senate Maryland] looking for EV community attention
by "Marc Breitman" <[EMAIL PROTECTED]>
6) Re: Allan Lichtman (sorry....this one's all ev related)
by "Marc Breitman" <[EMAIL PROTECTED]>
7) Re: Deka AGM vs. Sanyo D nicad
by "Philippe Borges" <[EMAIL PROTECTED]>
8) Re: Deka AGM vs. Sanyo D nicad
by "Philippe Borges" <[EMAIL PROTECTED]>
9) Re: Help with Lawn Mower Conversion
by "Philippe Borges" <[EMAIL PROTECTED]>
10) Re: Deka AGM vs. Sanyo D nicad
by "Robert Chew" <[EMAIL PROTECTED]>
11) Re: Efficiency of flooded lead acids
by "Ted C." <[EMAIL PROTECTED]>
12) Re: Efficiency of flooded lead acids
by "Robert Chew" <[EMAIL PROTECTED]>
13) RE: Deka AGM vs. Sanyo D nicad (6000 nicad cells in a drag racer)
by "Don Cameron" <[EMAIL PROTECTED]>
--- Begin Message ---
On Sun, 14 May 2006 09:01:42 +1000, James Massey
<[EMAIL PROTECTED]> wrote:
>To use a small 'fridge' compressor you will need an inverter at least 5x
>the nominal wattage to run it. [I had the opportunity to evaluate one a
>couple of years ago for a RE system, the unit was a small 'fridge', 60W
>nominal, we looked at 'hacking' the wiring to run the thermostat to the
>control switch of the inverter. A 250W inverter struggled to start it -
>about one in ten starts it failed. A 350W inverter seemed to go OK, but the
>cost to do the modification became unviable at this point - they just let
>the big inverter "fire up" on each fridge start or door opening (the inside
>light)].
No relevance to a compressor operating with the outlet at atmospheric
pressure. The compressor will essentially freewheel during starting.
Point of reference, I use a 100 watt nominal hermetic compressor as my
refrigerant recovery compressor. It starts unloaded - freewheeling.
It is mounted in an old equipment box along with necessary valving and
an old 250 watt inverter. The inverter is there so that automotive
systems can be recovered without needing shore power. That small
inverter easily starts and runs this compressor. This is an old
inverter without the large surge capacity that modern ones have. The
compressor doesn't need it because it starts unloaded.
>
>In addition, you will need to remember to oil the pump intake, which is
>attached to the vacuum reservoir, so is not so easy to do, and the pump
>outlet will be spraying that oil out somewhere and making a mess. This
>holds for any vacuum pump requiring lubrication to work - pumps off diesel
>ICEs are another example.
Not necessary. Depending on the compressor and the volume of air
flow, either nothing will need to be done - the oil will remain inside
the can, or an exhaust oil separator that drains back to the inlet may
be necessary to trap and recycle oil mist. This is a standard
off-the-shelf refrigeration part that costs only a few dollars.
A length of oh, 1" copper tubing maybe 6" long filled with fine steel
wool that acts as a coalescing filter can be made at home. Flow from
the compressor enters at the side bottom and exits at the top. At the
bottom is a port with a very small orifice that connects to the
intake. This port bleeds back the trapped oil without allowing much
gas to short-circuit back to the suction line.
>
>So the answer is yes, you could use a 'frige' pump to provide brake vacuum
>for an EV, but is it worth the hassle?
>
>My take is that it is another on the list of "yes it can be made to work
>for an EV, but how practical is it?"
Hassle? No more than any other pump adapted to the application and
there are several benefits, not the least of which is that the pump
will be essentially silent. Used refrigerator pumps are essentially
give-aways from places that recycle refrigerators.
There are a few considerations. Probably the most important is motor
cooling. The hermetic compressor relies almost completely on the flow
of cold suction gas for cooling. When there is no flow, such as in a
dead-head vacuum application, the motor will quickly overheat and
fail. There are solutions. One is to acquire a compressor with an
oil cooler. This is a separate coil attached to the compressor
through which the compressor's lube oil is circulated. This type of
compressor is common on domestic freezers where the suction side
operates at a partial vacuum and the flow is very low.
Cycling the compressor with a vacuum pressure switch is another
option, though the slight noise of starting and stopping might be
undesirable.
Yet another is a 3-way pneumatic valve in the inlet line. Switched
one way, flow comes from the reservoir to the compressor. Switched
the other way, flow comes from the atmosphere through a suitable air
filter and flow restrictor. The vacuum control switch toggles this
valve. Since the unloaded flow will be considerable, an oil separator
on the outlet is probably a necessity. The 3-way valve should be the
type that contains a check valve so that air can't flow backward into
the brake system when the valve toggles, as the compressor will be
allowed to idle much closer to atmospheric pressure. Or a power
brake-type check valve can be used in-line.
An alternative to the three way valve and one more likely to be easily
and cheaply available is an ordinary 12 volt automotive valve such as
used on emission systems. A NO valve would be preferable but either
action is fine. This valve is teed into the compressor inlet valve
downstream of the check valve. The other side is open to air through
a suitable air filter. When sufficient vacuum is developed in the
reservoir, the valve is de-energized, allowing air into the compressor
inlet. The check valve prevents the air from entering the reservoir.
A refrigeration compressor would be my choice if I needed to operate
power brakes. Quietness and reliability would be the two most
important attributes.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
>"Wattering hassles"? Once every three months or so you connect a pipe
>to the inlet of the pack and pump water in until it comes out the other
>end. Takes maybe 20 minutes and a few gallons of distilled water.
Yes, what a pain. I'd much rather have to trace a bad cell than water.
But then again I'm an electronics geek and not a gardener.. (watering,
gardening, get it? haha.. nevermind.. :)
>The 250 amp limit is no problem if you have a higher voltage pack. Using
>a smaller sedan or a Rabbit or a Porsche 914 with something like a 180v
>pack and a Zilla-Z1K you'd have a freeway capable vehicle with very nice
>range (maybe 40-50 miles). Paul Wallace uses a 144v pack of the 180AH
>SAFTS in his S10 truck and gets about 50-60 miles range.
My goal is to be able to deliver 1000 A at 160 volts to the motor. If
I use 180 V of the high rate Sanyos it should be able to do that. 180
V of Safts won't even get close. Even with a heavy 348 V Saft pack
bucking down that's still only 580 A. Yes, I'm a closet speed freak..
>:o)
>SAFT claims 2000 cycles if properly maintained. The trick seems to be to
>water them more often than the SAFT spec though.
It's a moot point. :)
Brad Baylor
--- End Message ---
--- Begin Message ---
G'day John - and all
At 12:15 AM 14/05/06 -0400, John De Armond wrote:
<snip>
No relevance to a compressor operating with the outlet at atmospheric
pressure. The compressor will essentially freewheel during starting.
Point of reference, I use a 100 watt nominal hermetic compressor as my
refrigerant recovery compressor. It starts unloaded - freewheeling.
OK, I accept that the vacuum system in an EV can be set up to use an
external check valve or changeover valve to start under zero differential -
but I'd tip that most people would want the easy life and use the valves in
the compressor as the non-return, so the compressor would be starting up
with something like -50kPa at the inlet, unless the vacuum was 'flat', but
not being used to refrigeration systems I have no idea what is a normal
pressure differential for a refrigeration compressor, and how big a load
this would represent.
It is mounted in an old equipment box along with necessary valving and
an old 250 watt inverter. The inverter is there so that automotive
systems can be recovered without needing shore power. That small
inverter easily starts and runs this compressor. This is an old
inverter without the large surge capacity that modern ones have. The
compressor doesn't need it because it starts unloaded.
An old 250W transformer based inverter that can deliver 500W for a couple
of minutes, or an old switched-mode that can deliver 500W for only a
fraction of a second? I had a 150W transformer-type inverter in the shop at
the same time that would start that little 'fridge' OK, but the customer
wasn't getting that one - so a 250W electronic one with 1000W surge was
tried - but the surge just wasn't long enough. I should have been clear
that I was referring to a typical cheap inverter.
>In addition, you will need to remember to oil the pump intake, which is
>attached to the vacuum reservoir, so is not so easy to do, and the pump
>outlet will be spraying that oil out somewhere and making a mess. This
>holds for any vacuum pump requiring lubrication to work - pumps off diesel
>ICEs are another example.
Not necessary. Depending on the compressor and the volume of air
flow, either nothing will need to be done - the oil will remain inside
the can, or an exhaust oil separator that drains back to the inlet may
be necessary to trap and recycle oil mist. This is a standard
off-the-shelf refrigeration part that costs only a few dollars.
Depending...may be... John, I'm guessing you haven't used a refrigeration
compressor as a vacuum pump for an on-road EV. Would you (are you confident
enough to take responsibility for?) cobble something together and throw it
in someone elses' EV who didn't know about these parts?
I'm being serious when I ask the question, since it is easy to sit at a
keyboard and offer advice about how to do things that we (as experienced
people in our trade) believe should be able to be done. If you are that
confident, then good, as I can see you being asked for advice on the
details about making a refrigeration compressor work as reliably as a
vehicle braking system must do.
A length of oh, 1" copper tubing maybe 6" long filled with fine steel
wool that acts as a coalescing filter can be made at home. <snip>
At his point I snip off a *great* discussion from John about how you can
use a refrigeration compressor and what you need to do to achieve this.
Obviously John has a great deal of knowlege about about refrigeration.
I don't. I can do electronics, electrical, motor control, PLCs, pneumatics,
instrumentation, a smattering of hydraulics and a bunch of other stuff.
I've never had the need to learn about refrigeration equipment. People
(including engineers and similarly trained people) come to me with things
that are too hard for them or require cross-trade decisions, but Johns'
post makes me doubt that I'd be able to select the right components to make
a successful (reliable) system based on a refrigeration compressor. I
really enjoy making things like this work, but I'd need to know a lot more
before I'd trust a system (i.e. put one in a vehicle for my wife to drive)
like this that I'd put together. Johns' post shows me how little I know
about refrigeration, less than I thought!
I stand by my comment, although I'll redefine it some, that it would be a
hassle for most people to make a refrigeration compressor be a reliable
source of vacuum for an EV. John and others who have worked with
refrigeration components can make the right decisions to get reliability. I
don't doubt that with instruction from someone with that knowlege pretty
much anyone could make a system work. But how much hassle would it be? I
grabbed an off-the-shelf solution, cheap (surplus), reliable that I can
drop into the vehicle with confidence, and get on with other bits.
John, my respect for the breadth of your knowlege continues to grow, but I
feel that you may be falling into the trap that I have done time and again
with the techs that I employ - things that are obvious to me I have
expected to be obvious to them, but turn out not to be so.
Regards
[Technik] James
--- End Message ---
--- Begin Message ---
Hi All,
i have measured rather crudely the efficiency of my SCS 225 flooded leads.
They range from 85% to 90%.
Is that right??
Cheers
_________________________________________________________________
Research and compare new cars side by side at carpoint.com.au
http://secure-au.imrworldwide.com/cgi-bin/a/ci_450304/et_2/cg_801459/pi_1004813/ai_833884
--- End Message ---
--- Begin Message ---
My original "e-lx" was simply a quickly thrown-together mix of bike parts
and some aluminum framing, an etek motor and some hand-made gearing to allow
the bike to still have 21 speeds. Although it beat the "school race" it
really wasn't any competition.
This year I was in the middle of a recumbent solar e-bike project when I
finally came to the conclusion the solar rayce was not happening.
http://www.solarbike.org/ Unfortunately my project partner refused to go on
with the project and spend all the money on batteries and such, and honestly
I had to agree. So lies an unfinished bike with motor attached in my garage,
and 2 boxes of solar panels.
On a side note, I've been trying to figure out how to (properly) use some of
my extra panels on my recently salvaged/refurbished battery powered lawnboy.
The panels generate anything from 0-6ish volts, and put out a max of around
220mA. (1.3watts per panel) I can fit probably 5 panels (4 comfortably) on
it, but still have a major voltage issue getting it up to the 24+v charging
level. I looked into charge pumps, but they only work on a fixed input, and
other microchips simply don't allow for that kind of voltage boost. Putting
5 in series will give me about 30v in high sun, but that doesn't end up
being very efficient, or probably very healthy for the batteries.
Preferably, as always, I'm looking for a way to build my own charging
circuit instead of forking over the money to buy something totally
unnecessary.
-Marc
--- End Message ---
--- Begin Message ---
TO ALL: I apologize for the political push.
Simply put, I'm looking for an upcoming EV race/event in Maryland. I'm more
trying to get him interested in EV's then I am trying to get you all
interested in him. So please ignore my original post, i understand it was
inappropriate.
-Marc
--- End Message ---
--- Begin Message ---
Hello,
i would like to precise one thing: near nobody went farther than 1500 cycles
with Saft STM because 99% EV using them were not serviced correctly !
These batteries DO 2750 cycles until 80% initial Capacity ! you can expect
that, we openned batteries with more than 1000 cycles on them, active
material was like new ! BUT few separators were dead (from short circuit) ,
battery death was from not enough watering which is a customer or mecanics
mistake.
In fact there is "one hand count" cars which passed the 1500 cycles mark
(100 000km for France PSA E-cars) BUT all without any range loss !
It appears than Saft tiny cells are not so good, Saft F cells (nimh) i
tested were bad at sharing well during hard discharge (now i know the group
i had were not matched by internal resistance)
I tested R/C type sub C (matched and zapped) with very good results at
discharge though still not possible to charge them in parallel without a
mess.
Your big challenge will be to charge serie string and discharge these
parralled serie strings...it works for racing but i will not try this for a
comuting EV, too much cells equal to much failure probability.
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: "Brad Baylor" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 12:28 AM
Subject: Re: Deka AGM vs. Sanyo D nicad
> Thanks everyone for the feedback! :)
>
> The KR-4400D sags to about a volt at 62 amps and capacity drops in
> half. You wouldn't want to pull that amount for more than a few
> seconds because of heating. I am also considering the high-rate
> N-4000DRL, that despite the higher cost might be a better choice, as
> capacity decreases much less and less heating occurs at high rate
> discharge (calculator says 89 A at 1 V, 196 A at .7). And life is
> exponentially inversely proportional to heat. Both are much stiffer
> than Safts and per weight the fast rate cells are about the same max
> power as Orbitals.
>
> Yeah about parallel strings... I have the same concerns about load
> sharing, which could limit the total max current and overly stress the
> strong strings, but it may not be an issue for this application.
> Single cells in parallel I could see having major load sharing issues,
> but much with higher voltage strings before paralleling occurs, with
> fairly linear resistors (interconnects and cabling) in series on each
> string, and overkill cooling keeping all the cells about the same
> temperature, I would think they should share roughly equally. And
> there's enough cells in series that high and low cells should roughly
> balance out. Worst case I can tweak by using resistors or more diodes
> in series with the strong strings. Or even add/remove cells, varying
> the total number in each string, but that might cause other issues.. I
> think this is only a potential issue at high rate discharge, and the
> load should tend to balance during the low rate periods (which is most
> of the time during discharge). I can't find anything to prove this, so
> I guess I'll be the test case. :)
>
> Risk management. Well I don't have a garage, so the car get's charged
> outside away from the house. The strings will be individually fused
> and I'll have a thermal cutoff (possibly a smoke detector cut off too
> :), but if there's a wreck sufficient to short a bunch of cells, I'll
> try to contain the damage with a fire extinguisher and run if
> necessary...
>
> Safts looked pretty interesting, even with the watering hassles, until
> I saw several posts that said 250 A is the max for long life. And also
> was pointed out by someone familiar with their use in European
> electrics, that 1500 cycles life was typical at 80% DOD, not the 3000
> claimed by Saft. Either way that's better than Sanyos at 80% DOD, but
> a moot point because of the 250 A limit.
>
> There's nothing wrong with slow charging using a series resistor
> dropping a higher voltage, forming a quasi-constant current source.
> I've done it for many years with no issues. It's on page 35 of Sanyo's
> nicad technical manual. Mike- I think I must have misused the term
> Badboy. I'm not fast charging, just Badboy in the sense that there's
> no transformer. Apologies for the confustion.
>
> My labor and dollar figures reflect my inexperience with most of the
> aspects of lead-acid, modifying the car to handle weight, finding the
> necessary components, buying ones that don't fit and trying again,
> welding equipment and learning to weld, paying an electrician to
> install a circuit (I'm not one and my insurance company would agree),
> etc.. I'll be over the max weight on the plate with lead-acid with no
> one in the car (this is the heavier Jetta GL model), and I still want
> decent braking and handling. So yeah upgrades are necessary.
>
> Deka's own manual has strict max voltage/temp guidelines for charging.
> Deviate from those and you'll get less life (even less than the
> already crappy life if you do it perfect). I admit, I'm biased against
> lead-acid. I've had nothing but bad experience with them over the
> years, never getting close to a reasonable amount of cycles. Yeah I've
> never tried them with an electric car before, but every time I look at
> the charts and graphs and read other's experiences of various
> lead-acid batteries, the word "sucks" is constantly running through my
> mind. :)
>
> Nicads other hand are very familiar to me and I shouldn't need as many
> tools, and will require mostly patience dealing with. Now that I
> think about it, my original estimate of 2 minutes per cell is probably
> not realistic. Maybe 5 minutes per cell for 200 hours cell assembly
> time? Considering my inexperience with lead-acid and all the
> associated stuff, seems the way to go (for me). Plus I've never worn
> out a Sanyo under normal use, which a car's typical loads will be
> (yeah, I've killed them in RC before, but 40C discharges and cells too
> hot to touch and will do that).
>
> How do you find a bad cell? First isolate the string by noting a
> change in output over time on the string voltage/current/AH monitor.
> After running a bit to put a load on the cells, pull the string and
> feel each cell. The warmest one is likely your bad cell. To confirm,
> put the string under load and compare the voltage of the warm one to
> the cool ones. I used that method for years on the RC planes with good
> success. The loads a car will put on these cells is nothing compared
> to the abuse a RC app inflicts, and I really don't expect to see many
> failures.
>
> It'll take me months before I'm ready for the battery and charger part
> of this project, and I'm out of money, so I have a while to think
> about all this.
>
> Brad Baylor
>
--- End Message ---
--- Begin Message ---
if i recall correctly there is an EV drag racer which use (or had used) 6000
nicad D cells...
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: "Don Cameron" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 2:13 AM
Subject: RE: Deka AGM vs. Sanyo D nicad
> Brad, I am looking forward to you progress with this type of pack - it
will
> be a first of this size for the list! I hope you will be sharing you
> experiences on a web site.
>
> Don
>
>
>
> Don Cameron, Victoria, BC, Canada
>
> see the New Beetle EV project www.cameronsoftware.com/ev
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Brad Baylor
> Sent: May 13, 2006 3:28 PM
> To: [email protected]
> Subject: Re: Deka AGM vs. Sanyo D nicad
>
> Thanks everyone for the feedback! :)
>
> The KR-4400D sags to about a volt at 62 amps and capacity drops in half.
You
> wouldn't want to pull that amount for more than a few seconds because of
> heating. I am also considering the high-rate N-4000DRL, that despite the
> higher cost might be a better choice, as capacity decreases much less and
> less heating occurs at high rate discharge (calculator says 89 A at 1 V,
196
> A at .7). And life is exponentially inversely proportional to heat. Both
are
> much stiffer than Safts and per weight the fast rate cells are about the
> same max power as Orbitals.
>
> Yeah about parallel strings... I have the same concerns about load
sharing,
> which could limit the total max current and overly stress the strong
> strings, but it may not be an issue for this application.
> Single cells in parallel I could see having major load sharing issues, but
> much with higher voltage strings before paralleling occurs, with fairly
> linear resistors (interconnects and cabling) in series on each string, and
> overkill cooling keeping all the cells about the same temperature, I would
> think they should share roughly equally. And there's enough cells in
series
> that high and low cells should roughly balance out. Worst case I can tweak
> by using resistors or more diodes in series with the strong strings. Or
even
> add/remove cells, varying the total number in each string, but that might
> cause other issues.. I think this is only a potential issue at high rate
> discharge, and the load should tend to balance during the low rate periods
> (which is most of the time during discharge). I can't find anything to
prove
> this, so I guess I'll be the test case. :)
>
> Risk management. Well I don't have a garage, so the car get's charged
> outside away from the house. The strings will be individually fused and
I'll
> have a thermal cutoff (possibly a smoke detector cut off too :), but if
> there's a wreck sufficient to short a bunch of cells, I'll try to contain
> the damage with a fire extinguisher and run if necessary...
>
> Safts looked pretty interesting, even with the watering hassles, until I
saw
> several posts that said 250 A is the max for long life. And also was
pointed
> out by someone familiar with their use in European electrics, that 1500
> cycles life was typical at 80% DOD, not the 3000 claimed by Saft. Either
way
> that's better than Sanyos at 80% DOD, but a moot point because of the 250
A
> limit.
>
> There's nothing wrong with slow charging using a series resistor dropping
a
> higher voltage, forming a quasi-constant current source.
> I've done it for many years with no issues. It's on page 35 of Sanyo's
nicad
> technical manual. Mike- I think I must have misused the term Badboy. I'm
not
> fast charging, just Badboy in the sense that there's no transformer.
> Apologies for the confustion.
>
> My labor and dollar figures reflect my inexperience with most of the
aspects
> of lead-acid, modifying the car to handle weight, finding the necessary
> components, buying ones that don't fit and trying again, welding equipment
> and learning to weld, paying an electrician to install a circuit (I'm not
> one and my insurance company would agree), etc.. I'll be over the max
weight
> on the plate with lead-acid with no one in the car (this is the heavier
> Jetta GL model), and I still want decent braking and handling. So yeah
> upgrades are necessary.
>
> Deka's own manual has strict max voltage/temp guidelines for charging.
> Deviate from those and you'll get less life (even less than the already
> crappy life if you do it perfect). I admit, I'm biased against lead-acid.
> I've had nothing but bad experience with them over the years, never
getting
> close to a reasonable amount of cycles. Yeah I've never tried them with an
> electric car before, but every time I look at the charts and graphs and
read
> other's experiences of various lead-acid batteries, the word "sucks" is
> constantly running through my mind. :)
>
> Nicads other hand are very familiar to me and I shouldn't need as many
> tools, and will require mostly patience dealing with. Now that I think
about
> it, my original estimate of 2 minutes per cell is probably not realistic.
> Maybe 5 minutes per cell for 200 hours cell assembly time? Considering my
> inexperience with lead-acid and all the associated stuff, seems the way to
> go (for me). Plus I've never worn out a Sanyo under normal use, which a
> car's typical loads will be (yeah, I've killed them in RC before, but 40C
> discharges and cells too hot to touch and will do that).
>
> How do you find a bad cell? First isolate the string by noting a change in
> output over time on the string voltage/current/AH monitor.
> After running a bit to put a load on the cells, pull the string and feel
> each cell. The warmest one is likely your bad cell. To confirm, put the
> string under load and compare the voltage of the warm one to the cool
ones.
> I used that method for years on the RC planes with good success. The loads
a
> car will put on these cells is nothing compared to the abuse a RC app
> inflicts, and I really don't expect to see many failures.
>
> It'll take me months before I'm ready for the battery and charger part of
> this project, and I'm out of money, so I have a while to think about all
> this.
>
> Brad Baylor
>
--- End Message ---
--- Begin Message ---
PMG 132 is 51rpm/V and can go without problems up to rated 72V
Etek is 70rpm/V 48V is the limit for long life
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: "Brad Baylor" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 3:21 AM
Subject: Re: Help with Lawn Mower Conversion
> The Briggs and Stratton Etek is ideal for this. It's 48 V, 6 HP cont,
> 15 HP max, about 90% efficient, and because it's permanent magnet,
> self regulates to about 3300 RPM. The same speed as a lawnmower gas
> engine. It looks like that was their intended market when they
> designed it. Unfortunately a month or two ago I read here that they
> discontinued it and that day ordered one for my own conversion. There
> may still be a few places that have it.
>
> I'd like to get 45 minutes mowing time, and from reading here, the
> Etek will need about 60 to 70 A average with 150 A peaks. 4 Deka 9A31s
> would do it, but additional weight up front would be about 200 lbs,
> which might be a bit much. Plus I think they're too big for the
> available space. 4 34DC-36 Orbitals could do it if I do a charge
> session in between. I've entertained the thought of 880 Sanyo D
> nicads, but the payback would never happen, using it only 30 or so
> times a year.
>
> BB600s would be ideal and you should use those. If I could get those,
> I'd use 80 in two 40 cell strings, hooked in parallel. Charge
> separately, and hook together for discharge (use diodes to isolate for
> safety).
>
> You need to limit the startup current on the motor, so perhaps a
> resistor briefly switched into the circuit would work. You could also
> rig a switch to apply partial power to the motor from say half the
> batteries (briefly only or else you'll unbalance the pack). Or if
> you're handy with electronics, fashion a PWM controller.
>
> There are a few other pancake motors like the Etek, one is made by
> Perm Motor, the PMG 132, but the speed-torque curves aren't quite
> drop-in for 48 V like the Etek. It would work great on 72 V though,
> and with a single string of BB600s should give decent runtime.
>
> Brad Baylor
>
--- End Message ---
--- Begin Message ---
Where can you buy these Saft batts the flooded nicad's. Sorry for my
ignorance.
I am sick of my poor range from my EV only 25 km's to 70%. I need at least a
comfortable 50km on a charge to be practical.
I don't mind ordering from Europe or even if there is a Aussie distributor
How much are these. I went on the Saft website and there was no indication o
n how to buy or the price.
Cheers
From: "Philippe Borges" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: <[email protected]>
Subject: Re: Deka AGM vs. Sanyo D nicad
Date: Sun, 14 May 2006 12:06:20 +0200
Hello,
i would like to precise one thing: near nobody went farther than 1500
cycles
with Saft STM because 99% EV using them were not serviced correctly !
These batteries DO 2750 cycles until 80% initial Capacity ! you can expect
that, we openned batteries with more than 1000 cycles on them, active
material was like new ! BUT few separators were dead (from short circuit) ,
battery death was from not enough watering which is a customer or mecanics
mistake.
In fact there is "one hand count" cars which passed the 1500 cycles mark
(100 000km for France PSA E-cars) BUT all without any range loss !
It appears than Saft tiny cells are not so good, Saft F cells (nimh) i
tested were bad at sharing well during hard discharge (now i know the group
i had were not matched by internal resistance)
I tested R/C type sub C (matched and zapped) with very good results at
discharge though still not possible to charge them in parallel without a
mess.
Your big challenge will be to charge serie string and discharge these
parralled serie strings...it works for racing but i will not try this for a
comuting EV, too much cells equal to much failure probability.
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: "Brad Baylor" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 12:28 AM
Subject: Re: Deka AGM vs. Sanyo D nicad
> Thanks everyone for the feedback! :)
>
> The KR-4400D sags to about a volt at 62 amps and capacity drops in
> half. You wouldn't want to pull that amount for more than a few
> seconds because of heating. I am also considering the high-rate
> N-4000DRL, that despite the higher cost might be a better choice, as
> capacity decreases much less and less heating occurs at high rate
> discharge (calculator says 89 A at 1 V, 196 A at .7). And life is
> exponentially inversely proportional to heat. Both are much stiffer
> than Safts and per weight the fast rate cells are about the same max
> power as Orbitals.
>
> Yeah about parallel strings... I have the same concerns about load
> sharing, which could limit the total max current and overly stress the
> strong strings, but it may not be an issue for this application.
> Single cells in parallel I could see having major load sharing issues,
> but much with higher voltage strings before paralleling occurs, with
> fairly linear resistors (interconnects and cabling) in series on each
> string, and overkill cooling keeping all the cells about the same
> temperature, I would think they should share roughly equally. And
> there's enough cells in series that high and low cells should roughly
> balance out. Worst case I can tweak by using resistors or more diodes
> in series with the strong strings. Or even add/remove cells, varying
> the total number in each string, but that might cause other issues.. I
> think this is only a potential issue at high rate discharge, and the
> load should tend to balance during the low rate periods (which is most
> of the time during discharge). I can't find anything to prove this, so
> I guess I'll be the test case. :)
>
> Risk management. Well I don't have a garage, so the car get's charged
> outside away from the house. The strings will be individually fused
> and I'll have a thermal cutoff (possibly a smoke detector cut off too
> :), but if there's a wreck sufficient to short a bunch of cells, I'll
> try to contain the damage with a fire extinguisher and run if
> necessary...
>
> Safts looked pretty interesting, even with the watering hassles, until
> I saw several posts that said 250 A is the max for long life. And also
> was pointed out by someone familiar with their use in European
> electrics, that 1500 cycles life was typical at 80% DOD, not the 3000
> claimed by Saft. Either way that's better than Sanyos at 80% DOD, but
> a moot point because of the 250 A limit.
>
> There's nothing wrong with slow charging using a series resistor
> dropping a higher voltage, forming a quasi-constant current source.
> I've done it for many years with no issues. It's on page 35 of Sanyo's
> nicad technical manual. Mike- I think I must have misused the term
> Badboy. I'm not fast charging, just Badboy in the sense that there's
> no transformer. Apologies for the confustion.
>
> My labor and dollar figures reflect my inexperience with most of the
> aspects of lead-acid, modifying the car to handle weight, finding the
> necessary components, buying ones that don't fit and trying again,
> welding equipment and learning to weld, paying an electrician to
> install a circuit (I'm not one and my insurance company would agree),
> etc.. I'll be over the max weight on the plate with lead-acid with no
> one in the car (this is the heavier Jetta GL model), and I still want
> decent braking and handling. So yeah upgrades are necessary.
>
> Deka's own manual has strict max voltage/temp guidelines for charging.
> Deviate from those and you'll get less life (even less than the
> already crappy life if you do it perfect). I admit, I'm biased against
> lead-acid. I've had nothing but bad experience with them over the
> years, never getting close to a reasonable amount of cycles. Yeah I've
> never tried them with an electric car before, but every time I look at
> the charts and graphs and read other's experiences of various
> lead-acid batteries, the word "sucks" is constantly running through my
> mind. :)
>
> Nicads other hand are very familiar to me and I shouldn't need as many
> tools, and will require mostly patience dealing with. Now that I
> think about it, my original estimate of 2 minutes per cell is probably
> not realistic. Maybe 5 minutes per cell for 200 hours cell assembly
> time? Considering my inexperience with lead-acid and all the
> associated stuff, seems the way to go (for me). Plus I've never worn
> out a Sanyo under normal use, which a car's typical loads will be
> (yeah, I've killed them in RC before, but 40C discharges and cells too
> hot to touch and will do that).
>
> How do you find a bad cell? First isolate the string by noting a
> change in output over time on the string voltage/current/AH monitor.
> After running a bit to put a load on the cells, pull the string and
> feel each cell. The warmest one is likely your bad cell. To confirm,
> put the string under load and compare the voltage of the warm one to
> the cool ones. I used that method for years on the RC planes with good
> success. The loads a car will put on these cells is nothing compared
> to the abuse a RC app inflicts, and I really don't expect to see many
> failures.
>
> It'll take me months before I'm ready for the battery and charger part
> of this project, and I'm out of money, so I have a while to think
> about all this.
>
> Brad Baylor
>
_________________________________________________________________
New year, new job there's more than 100,00 jobs at SEEK
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek%2Ecom%2Eau&_t=752315885&_r=Jan05_tagline&_m=EXT
--- End Message ---
--- Begin Message ---
The short answer. Yes
The long answer. ( http://www.sandia.gov/pv/docs/PDF/batpapsteve.pdf ) or
( http://xtronics.com/reference/batterap.htm )
Ted
Olympia, WA
N47 02.743 W122 53.772
----- Original Message -----
From: "Robert Chew" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 12:17 AM
Subject: Efficiency of flooded lead acids
Hi All,
i have measured rather crudely the efficiency of my SCS 225 flooded leads.
They range from 85% to 90%.
Is that right??
Cheers
_________________________________________________________________
Research and compare new cars side by side at carpoint.com.au
http://secure-au.imrworldwide.com/cgi-bin/a/ci_450304/et_2/cg_801459/pi_1004813/ai_833884
--- End Message ---
--- Begin Message ---
Thank you for that.
Cheers
From: "Ted C." <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: <[email protected]>
Subject: Re: Efficiency of flooded lead acids
Date: Sun, 14 May 2006 05:06:00 -0700
The short answer. Yes
The long answer. ( http://www.sandia.gov/pv/docs/PDF/batpapsteve.pdf ) or (
http://xtronics.com/reference/batterap.htm )
Ted
Olympia, WA
N47 02.743 W122 53.772
----- Original Message ----- From: "Robert Chew"
<[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 12:17 AM
Subject: Efficiency of flooded lead acids
Hi All,
i have measured rather crudely the efficiency of my SCS 225 flooded leads.
They range from 85% to 90%.
Is that right??
Cheers
_________________________________________________________________
Research and compare new cars side by side at carpoint.com.au
http://secure-au.imrworldwide.com/cgi-bin/a/ci_450304/et_2/cg_801459/pi_1004813/ai_833884
_________________________________________________________________
Search for local singles online @ Lavalife - Click here
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Flavalife9%2Eninemsn%2Ecom%2Eau%2Fclickthru%2Fclickthru%2Eact%3Fid%3Dninemsn%26context%3Dan99%26locale%3Den%5FAU%26a%3D22141&_t=751140432&_r=emailtagline_may_search&_m=EXT
--- End Message ---
--- Begin Message ---
Philippe, I looked on EVAlbum - do you have any further information on this
racer? I have looed on EVAlbum, Nedra and googled this without much luck.
Don
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Philippe Borges
Sent: May 14, 2006 3:14 AM
To: [email protected]
Subject: Re: Deka AGM vs. Sanyo D nicad
if i recall correctly there is an EV drag racer which use (or had used) 6000
nicad D cells...
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: "Don Cameron" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, May 14, 2006 2:13 AM
Subject: RE: Deka AGM vs. Sanyo D nicad
> Brad, I am looking forward to you progress with this type of pack - it
will
> be a first of this size for the list! I hope you will be sharing you
> experiences on a web site.
>
> Don
>
>
>
> Don Cameron, Victoria, BC, Canada
>
> see the New Beetle EV project www.cameronsoftware.com/ev
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Brad Baylor
> Sent: May 13, 2006 3:28 PM
> To: [email protected]
> Subject: Re: Deka AGM vs. Sanyo D nicad
>
> Thanks everyone for the feedback! :)
>
> The KR-4400D sags to about a volt at 62 amps and capacity drops in half.
You
> wouldn't want to pull that amount for more than a few seconds because of
> heating. I am also considering the high-rate N-4000DRL, that despite the
> higher cost might be a better choice, as capacity decreases much less and
> less heating occurs at high rate discharge (calculator says 89 A at 1 V,
196
> A at .7). And life is exponentially inversely proportional to heat. Both
are
> much stiffer than Safts and per weight the fast rate cells are about the
> same max power as Orbitals.
>
> Yeah about parallel strings... I have the same concerns about load
sharing,
> which could limit the total max current and overly stress the strong
> strings, but it may not be an issue for this application.
> Single cells in parallel I could see having major load sharing issues, but
> much with higher voltage strings before paralleling occurs, with fairly
> linear resistors (interconnects and cabling) in series on each string, and
> overkill cooling keeping all the cells about the same temperature, I would
> think they should share roughly equally. And there's enough cells in
series
> that high and low cells should roughly balance out. Worst case I can tweak
> by using resistors or more diodes in series with the strong strings. Or
even
> add/remove cells, varying the total number in each string, but that might
> cause other issues.. I think this is only a potential issue at high rate
> discharge, and the load should tend to balance during the low rate periods
> (which is most of the time during discharge). I can't find anything to
prove
> this, so I guess I'll be the test case. :)
>
> Risk management. Well I don't have a garage, so the car get's charged
> outside away from the house. The strings will be individually fused and
I'll
> have a thermal cutoff (possibly a smoke detector cut off too :), but if
> there's a wreck sufficient to short a bunch of cells, I'll try to contain
> the damage with a fire extinguisher and run if necessary...
>
> Safts looked pretty interesting, even with the watering hassles, until I
saw
> several posts that said 250 A is the max for long life. And also was
pointed
> out by someone familiar with their use in European electrics, that 1500
> cycles life was typical at 80% DOD, not the 3000 claimed by Saft. Either
way
> that's better than Sanyos at 80% DOD, but a moot point because of the 250
A
> limit.
>
> There's nothing wrong with slow charging using a series resistor dropping
a
> higher voltage, forming a quasi-constant current source.
> I've done it for many years with no issues. It's on page 35 of Sanyo's
nicad
> technical manual. Mike- I think I must have misused the term Badboy. I'm
not
> fast charging, just Badboy in the sense that there's no transformer.
> Apologies for the confustion.
>
> My labor and dollar figures reflect my inexperience with most of the
aspects
> of lead-acid, modifying the car to handle weight, finding the necessary
> components, buying ones that don't fit and trying again, welding equipment
> and learning to weld, paying an electrician to install a circuit (I'm not
> one and my insurance company would agree), etc.. I'll be over the max
weight
> on the plate with lead-acid with no one in the car (this is the heavier
> Jetta GL model), and I still want decent braking and handling. So yeah
> upgrades are necessary.
>
> Deka's own manual has strict max voltage/temp guidelines for charging.
> Deviate from those and you'll get less life (even less than the already
> crappy life if you do it perfect). I admit, I'm biased against lead-acid.
> I've had nothing but bad experience with them over the years, never
getting
> close to a reasonable amount of cycles. Yeah I've never tried them with an
> electric car before, but every time I look at the charts and graphs and
read
> other's experiences of various lead-acid batteries, the word "sucks" is
> constantly running through my mind. :)
>
> Nicads other hand are very familiar to me and I shouldn't need as many
> tools, and will require mostly patience dealing with. Now that I think
about
> it, my original estimate of 2 minutes per cell is probably not realistic.
> Maybe 5 minutes per cell for 200 hours cell assembly time? Considering my
> inexperience with lead-acid and all the associated stuff, seems the way to
> go (for me). Plus I've never worn out a Sanyo under normal use, which a
> car's typical loads will be (yeah, I've killed them in RC before, but 40C
> discharges and cells too hot to touch and will do that).
>
> How do you find a bad cell? First isolate the string by noting a change in
> output over time on the string voltage/current/AH monitor.
> After running a bit to put a load on the cells, pull the string and feel
> each cell. The warmest one is likely your bad cell. To confirm, put the
> string under load and compare the voltage of the warm one to the cool
ones.
> I used that method for years on the RC planes with good success. The loads
a
> car will put on these cells is nothing compared to the abuse a RC app
> inflicts, and I really don't expect to see many failures.
>
> It'll take me months before I'm ready for the battery and charger part of
> this project, and I'm out of money, so I have a while to think about all
> this.
>
> Brad Baylor
>
--- End Message ---
