EV Digest 6961
Topics covered in this issue include:
1) Re: Controler space
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Sevcon 128/12V DC/CD (Fixed)
by Dave Stensland <[EMAIL PROTECTED]>
3) Re: Brush timing advance, nothing new :-)
by "Andrew Kane" <[EMAIL PROTECTED]>
4) Re: Wheel Hub Motors?
by "peekay" <[EMAIL PROTECTED]>
5) Re: reed switch application
by "Michaela Merz" <[EMAIL PROTECTED]>
6) Re: An Ebay find?
by Bill & Nancy <[EMAIL PROTECTED]>
7) DC to DC input circuit breaker trips
by Iron Mountain Films <[EMAIL PROTECTED]>
8) Re: Wheel Hub Motors?
by Dan Frederiksen <[EMAIL PROTECTED]>
9) Re: I have an IDEA!
by "Kaido Kert" <[EMAIL PROTECTED]>
10) Re: ???kWh EV battery pack
by Victor Tikhonov <[EMAIL PROTECTED]>
11) Re: Cheap
by "Shaun Williams" <[EMAIL PROTECTED]>
12) Re: Cheap
by "Shaun Williams" <[EMAIL PROTECTED]>
13) Re: Cheap
by Victor Tikhonov <[EMAIL PROTECTED]>
14) Re: To Gear or Not to Gear a Motorcycle (was Manly EV's, etc.)
by "Loni" <[EMAIL PROTECTED]>
15) Project #3 is a Lawn Mower
by mike golub <[EMAIL PROTECTED]>
16) Re: Make it
by Dan Frederiksen <[EMAIL PROTECTED]>
17) RE: DC to DC input circuit breaker trips
by "Claudio Natoli" <[EMAIL PROTECTED]>
18) Re: Cheap
by Victor Tikhonov <[EMAIL PROTECTED]>
19) Re: VS: Re: Cheap
by "Shaun Williams" <[EMAIL PROTECTED]>
20) Re: Cheap
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: Chains and belts (was Re: ft-lbs or lbs-ft
by Victor Tikhonov <[EMAIL PROTECTED]>
22) Re: AGM vs Gel
by Victor Tikhonov <[EMAIL PROTECTED]>
23) Re: Cheap
by "Shaun Williams" <[EMAIL PROTECTED]>
24) Re: AGM vs Gel
by Victor Tikhonov <[EMAIL PROTECTED]>
25) RE: AGM vs Gel
by Mike Willmon <[EMAIL PROTECTED]>
26) Nobody wants my money.. (rant for the day)
by Ian Hooper <[EMAIL PROTECTED]>
27) Re: Nobody wants my money.. (rant for the day)
by Dan Frederiksen <[EMAIL PROTECTED]>
28) Re: ???kWh EV battery pack / Gel vs. AGM / small vs. big battery
by Markus Lorch <[EMAIL PROTECTED]>
29) RE: Nobody wants my money.. (rant for the day)
by Mike Willmon <[EMAIL PROTECTED]>
30) Re: DC to DC input circuit breaker trips
by "Evan Tuer" <[EMAIL PROTECTED]>
31) n00b in your midst
by "John Labrey" <[EMAIL PROTECTED]>
--- Begin Message ---
Phelps wrote:
According to the Internet site I just came from.
http://www.newton.dep.anl.gov/askasci/eng99/eng99134.htm
Welding in space is not possible with current unless you provide a
gas that can start a arc...
No; this is not the case. At the breakdown voltage between the two
metals, the electric field strength is high enough to rip electrons
loose from the metals themselves. The electrons form the "gas" that
carries the current from one to the other. The electrons slam into the
positive side, giving up their kinetic energy and causing major heating
at the point of contact. When the positive metal gets hot enough from
this, positive metal ions start boiling off, and become a second "gas"
to carry charge in the opposite direction. These positive ions bombard
the negative side, causing it to heat up as well.
Anyone who has used high power vacuum tubes has seen this effect. When
you overload the tube, it can arc over between cathode and plate, heat
them to incandescence, and they will melt and weld.
With this same thought a controller switch sealed in a vacuum would
have no arc...
Yes, it will (see above). In fact, the breakdown voltage in a vacuum is
*lower* than it would be with air. Air is a better insulator than a vacuum.
However, air contains oxygen. Once you do strike an arc in air, the
oxygen erodes the metal very quickly -- much quicker than in vacuum.
And as far as noise I am sure that the arch would be a good part of
the noise.
Do you mean acoustic noise (the "clack" of a contactor pulling in)? This
is purely mechanical; a contactor is just as loud with no current
flowing as it is at full load.
Or do you mean electrical noise (as in RF interference)? This is always
present with contacts, regardless of whether there is air, vacuum, oil,
or anything else between them. The electrical noise is caused by the
sudden (nearly instantaneous) change in voltage and current as the
contact opens and closes the circuit.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Thanks for the tip, Jeff.
It's working now that I replaced the power MOSFETS with new ones (~$30
delivered), changed out the open "R2" resistor with a good one, and
replaced the blown on indicator lamp.
-Dave
Jeff Shanab wrote:
If you had said 1984 I would suspect the standard death of most dc-dc
converters. Increased esr in the main switching capacitors until they
can't oscilate fast enough and it stops after 1 cycle. (measureing
capacitance is useless, need to measure esr.) On the dc-dc's I had to
fix all the time, If they were over 15 years old I just replaced all the
electrolytic caps and check the switching transistor, 90% of the time
that was it.
The other death of the dc-dc's I have fixed is the main switching
transistors gives up the ghost, failing shorted, usually taking out
other stuff along the way. Some units are designed so close on the caps
that if they drift a little it stops working, some are designed so
stressed on the primary switching element that 2 year service life is
normal. (this was the way of samsung monitors and chaep TV's for years)
I recommend the iota series.
--- End Message ---
--- Begin Message ---
It's a good job the German Navy didn't have any A123 cells to put in that boat.
On 6/28/07, Bill Dube <[EMAIL PROTECTED]> wrote:
Yesterday, I visited the unbelievably good technology and science
museum (Deutsches Museum) in Munich, Germany. It was a major treat to
see the first German U-boat, the U1 on display:
http://www.deutsches-museum.de/en/sammlungen/verkehr/maritime-exhibition/u1/
What I found particularly amusing is that they had
mechanically-adjustable brush timing on the electric propulsion
motors. There are hand wheels that worked threaded actuators to move
the brush rigging. The range of movement looked very broad, perhaps
20 degrees or more. Here is a picture showing the details of this
1906 state-of-the-art brush advance system.
http://www.killacycle.com/photos/misc/DSCN1903.JPG
100 years later and we are still using the same stuff. :-)
Bill Dube'
--- End Message ---
--- Begin Message ---
try agnimotors, india
----- Original Message -----
From: "owen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, June 28, 2007 4:51 AM
Subject: Re: Wheel Hub Motors?
> i aready asked how much
>
> "We can supply wheel motors and drives to be fitted by the customer to
> almost any type of vehicle. At present they are all being built by hand
to
> customer order; nothing is available 'off the shelf'. We quote for each
> application individually. (As a rough guide, the HPD30 motors are priced
at
> GBP £7420 each and the master controller for 2-wheel drive is GBP £4000.
> This is the cheapest Hi Pa drive option available)."
>
> owen
>
> ----- Original Message -----
> From: "Joseph Tahbaz" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Monday, June 25, 2007 1:45 PM
> Subject: [SPAM] Re: Wheel Hub Motors?
>
>
> > PML makes hub motors, though I don't know if you can just order a
> > bunch yourself.
> >
> > On 6/24/07, Rob Hogenmiller <[EMAIL PROTECTED]> wrote:
> >> Are there any available wheel hub motors?
> >>
> >>
> >>
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.472 / Virus Database: 269.9.9/870 - Release Date: 6/26/2007
10:07 AM
>
>
--- End Message ---
--- Begin Message ---
This is exactly the setup I have in my truck since about 1/2 year. I
haven't had any problems as it takes about 150A for the reed contact to
close. That gives me some headroom to apply power with my foot on the
brake, i.e. while have to start without rolling backwards. I test the
setup from time to time and it works reliable. I simple way to add a bit
more safety.
I pulled the reed switch from the casing of a cheapo house alert system.
mm./
> But if you want this to be treated as a major error, then the NO contact
> of the relay should be wired directly from the relay coil to switched
> +12v, so the relay latches in even after you release the brake pedal. As
> for the first circuit, you'd have to turn the key off and back on to
> re-energize the main contactor.
>
> In these circuits, I did not bother to show a diode or MOV across the
> relay coils.
--- End Message ---
--- Begin Message ---
Does anyone have any information about the battery management and
charging system on this vehicle and how well it protected the batteries?
I've also noticed that on other ads by Blue Sky Motors that tebattery
pck is not the originals.
Bill
Lawrence Rhodes wrote:
> Bidding ended at almost 38k. Bluesky is the seller. Lawrence
Rhodes......
> ----- Original Message ----- From: "Danny Miller" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Tuesday, June 26, 2007 12:37 AM
> Subject: Re: An Ebay find?
--- End Message ---
--- Begin Message ---
According to the archives, it seems a similar problem
has come up before, but I don't know if there was a
definitve answer or a remedy for it.
I am running a Zilla 1kLV and a Zivan Ng-3 as a DC to
DC in a 136 volt system. I have had several internal
10 amp fuses blow in the Zivan and re-inserted a 7.5
circuit breaker which saves me from having to pull
apart the Zivan. After many breaker trips, I finally
got curious enough and put a shunt on the 12 volt
input to the cars electrical system to see if i could
detect what was tripping it. Everything works
perfectly until I really step on it. Even after
setting the Zilla to a rather tame 400 amps and a low
bat voltage of 120, it still trips. And this is with
almost no current draw at all (daytime driving maybe
3-5 amps at 14 volts. I even replaced the 7.5 with a
new 8 amp breaker and it still trips.
This sounds like a problem that a gentleman with the
jeep cherokee was having with a DCP DC to DC.
What was the solution in his case?
I have checked the pot box and it looks smooth all the
way to 5k.
This DC to DC is always on and automatically cycles
its fan off.
Lee Hart came up with a solution for the DC to DC that
blew fuses on start up. I'm not sure that this would
help in my case.
The best theory so far is some kind of noise issue,
but could this still be the case with the Zilla turned
down so far, (I pull about 175 amps now) the voltage
sag is about 140 down to 127v.
I have little electronics knowledge, but I am a pretty
good problem solver. The car is my daily driver when
I don't ride my electric recumbent and has been
reliable transportation except for this annoying
tripping. I had an old 40amp Todd PC-40 that lasted a
long time after installing the zilla. But if this is
an issue of noise from the zilla that could be what
killed it.
I know both of these units are actually AC input
devices but the Zivan came from Greg McCrea of
Electric Conversions a Zivan Dealer and repair center.
It runs beautifully with everything on in the car at
about 45 amps.
Any insights would be much appreciated
-Mike Malmberg
92 Civic
(Jose Baer's old car)
____________________________________________________________________________________
Choose the right car based on your needs. Check out Yahoo! Autos new Car
Finder tool.
http://autos.yahoo.com/carfinder/
--- End Message ---
--- Begin Message ---
owen wrote:
i aready asked how much
"We can supply wheel motors and drives to be fitted by the customer to
almost any type of vehicle. At present they are all being built by
hand to customer order; nothing is available 'off the shelf'. We
quote for each application individually. (As a rough guide, the HPD30
motors are priced at GBP £7420 each and the master controller for
2-wheel drive is GBP £4000. This is the cheapest Hi Pa drive option
available)."
owen
a classic example of b2b pricing. that's the price of an entire nice
brand new car for each motor.
it's of course quite impossible to make it any cheaper than that. they
are even sacrificing their lives to get them to us so cheaply and we
should praise them for it and never dare question it :)
--- End Message ---
--- Begin Message ---
On 6/28/07, Mike Willmon <[EMAIL PROTECTED]> wrote:
Those are only 2.4 Amp hour packs. Four in series would give you a 144V 2.4AH
pack. For a typical size conversion if you assume
you want 15KWh pack, you might get away less because of the weight reduction,
but say 15KWh. You would need 43 parallel strings of
4-series batteries. At $169 each that would be 43 x 4 x $169 = $29,068. Thats
not be cheap, but it would work. ;-)
Mike,
Anchorage, Ak.
Range and stored energy is one thing but power is more important to
even get moving ...
One 4-pack string will provide you about 3,5KW of maximum power ( A123
is about 10C discharge capable, so 24 amps discharge @ 144v ~3,5KW )
So either your car is going to move veeery carefully with insane
gearing .. or you need more power. Not necessarily 43 parallel
strings, but at least four or five of them and that is if you have a
very light car, ten @35KW would be a sane minimum for any reasonable
performance.
Thats completely ignoring the range ...
-kert
--- End Message ---
--- Begin Message ---
Yes, thanks for noting Peter. The capacities I mentioned are
for 1hr discharge rate and you have to make adjustment for
20hr rate usually advertised by the sales people.
If you need x Ah batteries at 1hr rate (for your voltage) to
provide needed Wh storage, look for up to 1.5x Ah at 20hr rate.
Example:
You want range that can be covered by 20 kWh pack and you use 200V system.
Battery capacity is 20,000/200=100Ah (at 1hr). So you better purchase
1.5*100Ah=150Ah (@20hr rate) batteries to get 100Ah at 1hr.
The worse the battery (mainly higher R_int) - the more you have to
oversize it (20hr rate capacity wise) to maintain desired 1hr capacity.
AFAIK for lead acid AGMs are best in that respect (smallest oversize
needed), followed by gels and then floodies.
Victor
Peter VanDerWal wrote:
Note: Victors numbers assume you are looking at the 1C (1hr) capacity of
the batteries. Most Lead-Acid batteries are rated at the 20hr or possibly
10hr capacity.
Roughly speeking you will need 40% more capacity at the 20hr rate to equal
the 1hr rate. In other words, if you want 20kwh at the 1 hr rate, you
will need batteries speced for 28kwh at the 20hr discharge rate.
Tehben,
Count for 4-5 miles range per each 1 kWh on board of good tuned EV.
That will give you idea of the pack size people use based on their
range, with some reserve.
For instance if you want to have 40 miles range you will spend
40/4=10kWh normally or 40/5=8kWh good case, so if you want reserve
for 50% DOD, your pack has to be 20kWh or 16kWh respectively.
Victor
--
'91 ACRX - something different
Tehben Dean wrote:
I know higher voltage less capacity and vise versa, but wondered are
there some general kWh sizes that are used for different types of EVs
e.g. pickups etc.?
Or is it get as much as you can fit in without grossly over weighting
the vehicle? :)
(this is assuming Lead batt's)
TEhben
--- End Message ---
--- Begin Message ---
On 6/28/07, Roger Stockton <[EMAIL PROTECTED]> wrote:
I believe that is it. I think more detailed mention of it was made by
Bill Dube and/or Rich Rudman back during discussions of the cells in the
V28 packs or the A123 cells (don't recall which). The basic idea is
that you need to weld one or more tabs to each end of the cell to
connect it to the main bars/plates anyway, so simply size the tab to
easily carry the expected current but to blow open if this limit is
grossly exceeded. My fuzzy memory is that there was mention of the
cells being used/available with either 1 or two tabs on each end, and
that each tab was either good for 75A or made a fairly nice 75A fuse.
They look like they'd carry a lot more than 75A, maybe this is the
sort of testing I need to do as Lee suggested.
> I'm thinking that should a module's capacity become severely depleted
> due to multiple blown cells it could be detected under load with a
> voltage comparison to other modules.
Yes, I think this is possibly the only economic/practical means of
sensing such a condition. Essentially, there must be an over/under
voltge monitor/BMS on each module anyway, so give it the smarts to
estimate the module's impedance based on voltage variation with varying
load. It would only work if the cell impedance was relatively well
controlled vs SOC and SOH (state of health)/life so that the increase
due to the loss of 10-20% of the paralleled cells is readily
distinguishable from the normal variations.
Do you think it would need to be this complicated? I was thinking that
a simple voltage comparison between modules under load would be
sufficient. Once again more testing is required but this might
requires quite a few cells to get an idea of what should work.
I am still of the opinion that it would not be economic to replace
failed cells in a module vs repalcing the module itself, but at least
this approach has the potential of lighting an idiot light, etc. to
alert the user to the need for battery service before a module fails
entirely and leaves them stranded.
Cheers,
Roger.
Thanks again Roger, I think that this is the approach that I'm going
to investigate;
1. Each cell fused.
2. Each module constantly monitored and compared under load.
If I get some result with a small quantity of cells using this
approach then on to the next hurdle; how to balance the modules!
Shaun
www.electric-echo.com
--- End Message ---
--- Begin Message ---
On 6/28/07, Tony Hwang <[EMAIL PROTECTED]> wrote:
I've done something like using nickel fuses. From testing, I'm using a 0.003" thick, maybe 1/16" wide
piece of nickel battery tab as a 10+ amp fuse (very very inaccurate "blowing" current!). The cell is
rated for max 4 amps discharge, but they are massively in parallel, so the fuse should work fine. The tabs are
1/8" wide, I just cut a little bit of it in the middle, so that the whole tab isn't high resistance. Also my
thinking is that by having the "fuse" part of the tab in the middle, it's farther from the cells, so it
will heat up more on high current draws?
- Tony
Hi Tony,
Wow, 3 thou seems awfully thin, even for 10A. Thanks for the
construction ideas, this is what I need to play with.
Cheers,
Shaun
www.electric-echo.com
--- End Message ---
--- Begin Message ---
This Roger's statement is valid assuming that failed cells just
painlessly removed from the circuit and no longer contribute as
when their series fuse blows, so there is no safety concerns.
If a cell gets damaged and there is no fuse (or it doesn't blow) the
cell may represent a resistor other cells continuously discharge into.
Discharge current may not be big enough to blow the fuse but will
routinely imbalance the pack jeopardizing good cells unless a BMS can
cope with it. Also, "resistor"-cell will generate heat which may or may
not be enough to cause melting of something near by or cause its
rupturing and outgas nasty chemicals. In this case you better know
about failed cell(s) and remove/replace them.
Victor
Roger Stockton wrote:
I doubt the benefit of being able to identify that a particular cell had
failed would justify the cost and complexity of the monitoring required
to provide the function. With most cells available now, the number in
parallel is dictated by the required capacity, not the required peak
current capability. The result is that, again, one can lose a fair
number of cells in any module before any of the remaining cells are
going to be stressed particularly by carrying the full load current on
their own.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
LiPol will give you much more range, perhaps 4 or 5 times as much. But
will cost a lot.
You are focusing on the motor and that is the least of your problems.
Thanks for the input and clarification. Of course it's true that there are
serious challenges in the range/packaging department, but I'm addressing
those as well. Two points in that regard: you can sqeeze plenty of LiPol
onto a bike chassis designed from scratch to be an EV, and there's good
logic behind Tesla Motors' rollout at the high end of the market, where
overall design panache and sporting character matter enough to justify the
$25,000 "Energy Storage System" cost (at least to several hundred buyers so
far). Of course, on a bike the ESS will be significantly less expensive.
BTW, I'm not all talk. My company is now sourcing components for a chassis
that is ready to roll as a testbed for the drive system. I've looked at
motors from Siemens, Brusa, Kollmorgen, and more, both ac and dc, and there
are a few promising candidates, but soon I'll nail one down (I'd like to
join Raser's tech demonstration program, but I'm not sure how seriously I
take them yet. Are there any products to date that license Symetron
motor/controller packages?). The reason I've focused so much on the motor is
that we'd like to hit as close to our performance targets as possible the
first time out. Wish us luck.
Lon Hull,
Portland, OR
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--- Begin Message ---
Well, I am almost done with the 98 Chevy Metro, and I
have driven over 6,000 miles on the 86 Toyota Pickup.
I recently purchased a MTD riding mower it looks like
the same model as Wayland's
http://www.austinev.org/evalbum/38
Of course, it is still stock and has a 12 HP B&S, a
38" cutting blade.
So I was looking for motor recommendations. I will
keep using it as a mower...And I was wondering if it
was necessary to put a controller on the motor or just
use the mowers speed control? It has reverse and
forward.
I also picked up a 78 Polaris snow machine, but I'm
not too concerned about that at the moment.
Thanks
Michael G, Fairbanks
___________________________________________________________________________________
You snooze, you lose. Get messages ASAP with AutoCheck
in the all-new Yahoo! Mail Beta.
http://advision.webevents.yahoo.com/mailbeta/newmail_html.html
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--- Begin Message ---
John G. Lussmyer wrote:
There was an interesting study some years ago (hmm, I need to find my
copy). The jist of it is that Incompetent people not only don't
realize they are incompetent, but they are completely unable to
recognize competency in others. So they always "know" they are right,
and anyone that disagrees with them is obviously stupid.
Sound familiar?
ahh the imprisoning irony
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--- Begin Message ---
Hi Mike,
> I am running a Zilla 1kLV and a Zivan Ng-3 as a DC to
> DC in a 136 volt system. I have had several internal
> 10 amp fuses blow in the Zivan and re-inserted a 7.5
> circuit breaker which saves me from having to pull
> apart the Zivan.
I'm wondering, since it happens when you "step on it", if it isn't the current
going in to the DC/DC input that's tripping the breaker (such as from
undervoltage on the input or too much load on the output), but current coming
back out of the nicely charged input caps of the DC/DC when the battery voltage
drops precipitously.
> I have little electronics knowledge,
Likewise, and I'm not familiar with the construction of the Zivan DC/DC, so
take advice from the experts here over mine, but on reading your post I
wondered if a diode on the input side of the DC/DC wouldn't fix your problem.
I'll stay tuned now for one of the regulars to tell us why this can't be right
(such as that the Zivan DC/DC already having this protection).
Cheers,
Claudio
--- End Message ---
--- Begin Message ---
Shaun Williams wrote:
Thanks Lee and Victor,
These are exactly the kind of devil-in-the-detail gotchas I'm looking
for and you've given me plenty of food for thought already! I'd
expected no less from two EVlist legends. :-)
Nah, I'm far from it. Constantly learning too.
Count Lee as double legend though :-)
> P.S. Victor, a few years ago I tripped over your MetricMind website
when I was naively investigating the possibility of purchasing an
electric vehicle, EVerything I've done since then, has been as a
result of that single inspirational web experience. Never
underestimate the value of the effort you've put into it, thanks.
Glad it had such a positive impact - thanks for the compliment!
Keep up good work and don't let anyone to discourage you!
Victor
--- End Message ---
--- Begin Message ---
On 6/28/07, Jukka <[EMAIL PROTECTED]> wrote:
Managing a 200 ah cell is not that expencive. With 3kw charger a complete
system is about 20% of the whole cost. And when integrated in to the cell
structures in mass production even much less.
I could estimate that ev hobbyist can get away with 10 000 USD with already
boxed and complete system in 2009 (180v200ah+bms+3kw charger). For now it's
available for beta testers and some vehicles are on the roads already. We make
1 system/month for evaf.org members. Current setups are 76,8v350ah for Elcats.
I know at least one user who is in silent mode on the list.
Are we talking Thunder Sky Jukka?
Shaun Williams.
www.electric-echo.com
--- End Message ---
--- Begin Message ---
Tony,
Using attachment tabs with narrower section calibrated to melt at
certain current is very common practice. In fact, even cheap fuses
sometimes are implemented by narrowing a PCB track, placing other
components away and have slots through fiber on both sides of such
"fuse" - same concept. Problem is you cannot [easily] replace such
fuse but if only one time protection is the main goal - it's OK choice.
Victor
Tony Hwang wrote:
I've done something like using nickel fuses. From testing, I'm using
a 0.003" thick, maybe 1/16" wide piece of nickel battery tab as a 10+
amp fuse (very very inaccurate "blowing" current!). The cell is rated
for max 4 amps discharge, but they are massively in parallel, so the
fuse should work fine. The tabs are 1/8" wide, I just cut a little
bit of it in the middle, so that the whole tab isn't high resistance.
Also my thinking is that by having the "fuse" part of the tab in the
middle, it's farther from the cells, so it will heat up more on high
current draws?
--- End Message ---
--- Begin Message ---
This reminds me to ask: teethed belts don't require as much tension as
V-ones and don't slip. Wonder why they aren't used more widely? Sure,
alternator and A/C compressor don't require exact timing as valves do,
but still, is it just noise and extra expense of teethed belts and
pulleys, or some other technical reasons?
Victor
Eric Poulsen wrote:
Peter VanDerWal wrote:
If you are looking for maximum efficiency, then you want to use the
largest sprockets possible. Otherwise it doesn't matter.
Using larger sprockets means that the chain/belt has to flex less going
around it and this causes less friction, resulting in higher efficiency.
Also means less actual tension on the belts themselves. 100 Ft-lbs on a
12" sprocket is 200 lbs tension. 100 Ft-lbs on a 6" sprocket is 400 lbs
tension.
--- End Message ---
--- Begin Message ---
No worries. Siemens drive regen is as programmable as BRUSA charger,
you can set it to limit max voltage during regen to any number
within working voltage range.
Yes, your BRUSA NLG513-SA can charge gels just fine, including top off
pulse cycling at final I or Ia charging phase if you want :-)
Victor
Tehben Dean wrote:
Well maybe I will go with Gel and do something for heating.
I am getting a NLG513-SA BRUSA battery charger so I should be able to
program it to do whatever charging scheme WE ;) come up with.
One thing I am wondering (Victor) with the Regen is that limited so it
won't overcharge the pack?
--- End Message ---
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Thanks Victor,
This is similar to what Jukka was explaining, I think.
It's extremely valuable information and unfortunately, to prove if
this is ever going to be something that occurs often in the real world
and therefore justify the complications of single cell visibility, I
need to build a large pack, but I don't want t build and invest large
pack until I have a good idea of how I'm going to build it, catch-22.
Am I being overly optimistic in hoping that these fault conditions can
be detected by constant module (group of paralleled cells) voltage
monitoring during discharge (even at rest?) and comparing module to
module voltages?
I wonder how are Tesla doing it...
On 6/28/07, Victor Tikhonov <[EMAIL PROTECTED]> wrote:
This Roger's statement is valid assuming that failed cells just
painlessly removed from the circuit and no longer contribute as
when their series fuse blows, so there is no safety concerns.
If a cell gets damaged and there is no fuse (or it doesn't blow) the
cell may represent a resistor other cells continuously discharge into.
Discharge current may not be big enough to blow the fuse but will
routinely imbalance the pack jeopardizing good cells unless a BMS can
cope with it. Also, "resistor"-cell will generate heat which may or may
not be enough to cause melting of something near by or cause its
rupturing and outgas nasty chemicals. In this case you better know
about failed cell(s) and remove/replace them.
Shaun
www.electric-echo.com
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Tehben Dean wrote:
Peter VanDerWal says:
Gel Cells are the worst.
AGMs perform the best in the cold, then floodeds and then Gel Cells.
I think I will stay clear of Gel Cells if they are the worst in cold
weather.
If other advantages of gels outweigh this particular shortcoming, you
can always install battery heaters.
Victor
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> Tehben Dean wrote:
>
> >>> Peter VanDerWal says:
> >>> Gel Cells are the worst.
> >>> AGMs perform the best in the cold, then floodeds and then Gel Cells.
> >
> > I think I will stay clear of Gel Cells if they are the worst in cold
> > weather.
> >
> Victor Tikhonov wrote:
>
> If other advantages of gels outweigh this particular shortcoming, you
> can always install battery heaters.
>
Or/and 2" foam insulation. I have 2" high density EPS "beadboard" in my wood
battery box, and with just parking in a heated
(55*F) garage my batteries never got below 65*F all winter here in Anchorage.
In fact on the days above 20*F I had to leave the
lid cracked a little to keep the temps from steadily rising after several days.
Mike,
Anchorage, Ak.
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So over the space of the last week or so I've been trying to buy some
motors and batteries. Who'd have thought it'd be so hard?!
ThunderSky..
Trying to order 40x 160Ah LFPs for the MX5. I emailed my contact
(Brandon), no reply. Used their online order form, no reply. Phoned
them, it rang out and hung up on me. *sigh*
Advanced DC..
I was hoping to talk to them about becoming a reseller for their
motors in Australia, since they're very under-represented over here.
Currently there just one guy over east (~2000 miles from here). So I
phoned them, left a voice mail, no reply. Used their online contact
form, no reply. Phoned them and left another voice mail, no reply.
It's a pity neither of these companies have much competition - maybe
that's why they don't worry too much about customer service..
End rant, thank you for listening ;)
-Ian
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I notice that too. quite bizarre how deeply irrational many companies
are. I inquired on some cells from Intellect (the irony :) but they
wanted to decide which cells I should buy. they categorically refused to
sell anything else to me...
not even sample quantity.
the humanity!
Dan
Ian Hooper wrote:
So over the space of the last week or so I've been trying to buy some
motors and batteries. Who'd have thought it'd be so hard?!
ThunderSky..
Trying to order 40x 160Ah LFPs for the MX5. I emailed my contact
(Brandon), no reply. Used their online order form, no reply. Phoned
them, it rang out and hung up on me. *sigh*
Advanced DC..
I was hoping to talk to them about becoming a reseller for their
motors in Australia, since they're very under-represented over here.
Currently there just one guy over east (~2000 miles from here). So I
phoned them, left a voice mail, no reply. Used their online contact
form, no reply. Phoned them and left another voice mail, no reply.
It's a pity neither of these companies have much competition - maybe
that's why they don't worry too much about customer service..
End rant, thank you for listening ;)
-Ian
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Theben,
if you go with a 100Ah battery you also half the amount of Amps you can
safely draw as compared to the 200Ah battery. To this applies to all
lead acid batteries I believe if you e.g. compare 100Ah gel with 200Ah
gel or 100Ah SLA with 200Ah SLA. I once read a good post ( I think from
Lee Hart) in the archives about 6V 200Ah vs. 12V 100Ah batteries. The
point made was that while you half the current drawn when going with
higher voltage batteries you typically do draw that current from
half-as-big batteries. I believe the conclusion was that there is no or
no great improvement.
I myself drive a pack of 160Ah gel (Varta/Exide which are I believe the
same/very similar to the dominators). I can easily draw up to 450A
briefly (then my curtis limits the current) now in the summer. I have
been driving longer hills with 200-250A constant current but was told
that gels live long if you do not draw more than their rated Ah figure.
I.e. 160A for a 160Ah battery. At only 160Ah my EV is not what I would
like to drive, hence I am looking at SAFT NiCd that apparently can deal
with 250-300A safely. I haven't found 6V higher current AGM at a good
price and the 12V Optima etc. have too low capacity for what I need (or
I need a different controller).
Hope this helps.
Markus
Tehben Dean schrieb:
<div class="moz-text-flowed" style="font-family: -moz-fixed">So do
people usually go to only 50%DOD or all the way to 80%DOD?
If I spec a battery at 100Ah 20hr rate (could someone explain the C's
discharge measurement?) I need to subtract 40% to approximate the
1hr/1C
Roughly speeking you will need 40% more capacity at the 20hr rate to
equal
the 1hr rate.
so that leaves 60Ah and if I only drain it to 80% that leaves 48Ah of
usable capacity.... correct?
And 48ah x 312v = 14976w ~ 15kwh
Count for 4-5 miles range per each 1 kWh on board of good tuned EV.
15kwh x 4 = 60. So with 26 100ah batteries at 80%DOD we get an
approximate 60mile range.
Comments....?
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Get ahold of George Hamstra at Netgain Technologies LLC http://www.go-ev.com/
They have a Dealer Application form right on their website.
But if you want to buy a motor immediately I'd go to one of their already
established dealers since they may have the motor you're
looking for on a shelf.
(same goes for ADC motors, you might get better resale service from a ealer who
has one or two in stock)
Mike,
Anchorage, Ak.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of Ian Hooper
> Sent: Thursday, June 28, 2007 12:50 AM
> To: ev@listproc.sjsu.edu
> Subject: Nobody wants my money.. (rant for the day)
>
>
> So over the space of the last week or so I've been trying to buy some
> motors and batteries. Who'd have thought it'd be so hard?!
>
> ThunderSky..
> Trying to order 40x 160Ah LFPs for the MX5. I emailed my contact
> (Brandon), no reply. Used their online order form, no reply. Phoned
> them, it rang out and hung up on me. *sigh*
>
> Advanced DC..
> I was hoping to talk to them about becoming a reseller for their
> motors in Australia, since they're very under-represented over here.
> Currently there just one guy over east (~2000 miles from here). So I
> phoned them, left a voice mail, no reply. Used their online contact
> form, no reply. Phoned them and left another voice mail, no reply.
>
> It's a pity neither of these companies have much competition - maybe
> that's why they don't worry too much about customer service..
>
> End rant, thank you for listening ;)
>
> -Ian
>
>
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On 6/28/07, Claudio Natoli <[EMAIL PROTECTED]> wrote:
Hi Mike,
> I am running a Zilla 1kLV and a Zivan Ng-3 as a DC to
> DC in a 136 volt system. I have had several internal
> 10 amp fuses blow in the Zivan and re-inserted a 7.5
> circuit breaker which saves me from having to pull
> apart the Zivan.
10A? That must be an NG-1 battery charger, not an NG-3, right?
I'm wondering, since it happens when you "step on it", if it isn't the current
going in to the
DC/DC input that's tripping the breaker (such as from undervoltage on the input
or too
much load on the output), but current coming back out of the nicely charged
input caps of
the DC/DC when the battery voltage drops precipitously.
I would say that's not possible, there is a rectifier at the input.
The NG series can have problems with low supply voltage, this can
result in overheating. I wonder if the current limiting or some
protection circuit is being confused by the sudden change in supply
voltage or excessive noise.
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