EV Digest 5918
Topics covered in this issue include:
1) Re: AC vs DC?
by "Death to All Spammers" <[EMAIL PROTECTED]>
2) RE: AC vs DC?
by "Michael Trefry" <[EMAIL PROTECTED]>
3) IB9000 NiMH Re: Currently most powerful bats or caps available?
by "Death to All Spammers" <[EMAIL PROTECTED]>
4) Re: Robot lawn mower
by "Michael Perry" <[EMAIL PROTECTED]>
5) Re: Motors
by "Roland Wiench" <[EMAIL PROTECTED]>
6) Re: Safety Question
by Jeff Shanab <[EMAIL PROTECTED]>
7) Re: Robot lawn mower
by Danny Miller <[EMAIL PROTECTED]>
8) RE: Safety question
by Cor van de Water <[EMAIL PROTECTED]>
9) Re: will not go
by Jeff Shanab <[EMAIL PROTECTED]>
10) Re: IB9000 NiMH Re: Currently most powerful bats or caps available?
by "Edward Ang" <[EMAIL PROTECTED]>
11) Re: Matt's got his EV grin!
by Jude Anthony <[EMAIL PROTECTED]>
12) RE: EVLN(Lithium-ion battery failures
by Cor van de Water <[EMAIL PROTECTED]>
13) Re: AC vs DC?
by James Massey <[EMAIL PROTECTED]>
14) Re: IB9000 NiMH Re: Currently most powerful bats or caps available?
by Jack Murray <[EMAIL PROTECTED]>
15) Re: AC vs DC?
by "Death to All Spammers" <[EMAIL PROTECTED]>
16) Re: AC vs DC?
by Bob Bath <[EMAIL PROTECTED]>
17) Re: Robot lawn mower
by Lee Hart <[EMAIL PROTECTED]>
18) RE: AC vs DC?
by "Don Cameron" <[EMAIL PROTECTED]>
19) RE: toyota prius donor car?
by Cor van de Water <[EMAIL PROTECTED]>
20) RE: "Ultracapacitor-Battery" blows away Current Lithium-Ion Batte
ry
by Cor van de Water <[EMAIL PROTECTED]>
21) RE: AC vs DC?
by "Michael Trefry" <[EMAIL PROTECTED]>
--- Begin Message ---
>From some of the reading I've been doing AC seems to be more
efficient than
> DC in an EV.
>
> Are there disadvantages to using an AC system? Is it more complex,
> expensive? Are there other limitations?
>
> It looks like 6v fla batteries are pretty standard, but all this
talk I'm
> seeing about batteries is making me curious about what the best
> cost/performance battery solution is.
>
> Ideally I'd like to get at least 60 miles on a charge, be able to
get up to
> at least 85mph and have some decent acceleration. I think a 0-60 in 20
> seconds car would drive me insane.
>
Check http://metricmind.com/prices.htm - he does have a cheaper
version not listed there, but lowest-possible-cost conversions usually
use DC. If you intend to go with something *other* than a lead-acid
pack, then an AC system isn't the majority of your expenses!
--- End Message ---
--- Begin Message ---
Thanks for the price list.
But what I'm really looking for is not necessarily the lost cost solution,
but the best solution for a cost and performance balance.
For instance I understand that at the lowest budget level I'd be looking at
6-8K, but since this is a "long term" project I can spread the costs out
over the course of however long it takes.
So let's say for instance I was willing to invest 15-20K in this, are there
better options than the standard 9v DC motor and 6v sla batteries.
I really have no idea what's available at this time. I don't know how old
the information I'm reading is and if anything better has come along since.
Just looking for some guidance :)
Thanks,
Mike
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Death to All Spammers
Sent: Monday, September 25, 2006 10:38 PM
To: [email protected]
Subject: Re: AC vs DC?
>From some of the reading I've been doing AC seems to be more
efficient than
> DC in an EV.
>
> Are there disadvantages to using an AC system? Is it more complex,
> expensive? Are there other limitations?
>
> It looks like 6v fla batteries are pretty standard, but all this
talk I'm
> seeing about batteries is making me curious about what the best
> cost/performance battery solution is.
>
> Ideally I'd like to get at least 60 miles on a charge, be able to
get up to
> at least 85mph and have some decent acceleration. I think a 0-60 in 20
> seconds car would drive me insane.
>
Check http://metricmind.com/prices.htm - he does have a cheaper
version not listed there, but lowest-possible-cost conversions usually
use DC. If you intend to go with something *other* than a lead-acid
pack, then an AC system isn't the majority of your expenses!
--- End Message ---
--- Begin Message ---
> 800 cycles, okay, good. So tell me about your project you are
planning on
> using these cells for. Where can I buy these for $5-$6? I can't find
these
> on their site.
>
F-cells seem like the best bet -
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1039 -
these folks also sell for $2/cell less on eBay.
--- End Message ---
--- Begin Message ---
BTW, I don't think you are *supposed* to give out your security code, if
these are built like the earliest units. I forget which... CIA I think...
but one of the branches where security was important. They bought a couple
of these type mowers, battery operated. In *those* at least, the security
code was to keep someone from stealing the mower. (If wheels were lifted off
the ground, the security code was necessary for it to start mowing again.)
Is this different?
As for weeds, I think the idea is to have it go off and mow before weeds get
more than 4" tall. If you have "tree trunk" weeds... it's been far too long.
<g> Does yours use the string cutters? Those are meant for non-stalk mowing.
(Stalks, per my friend, will chew up the strings.)
----- Original Message -----
From: "Danny Miller" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, September 25, 2006 11:23 AM
Subject: Re: Robot lawn mower
> I have had a Robomower for over 5 years for my yard of about 1/2 acre
> between the front and back. I'm allergic to grass. I love it. I think
> it reports 400 hours on it.
--- End Message ---
--- Begin Message ---
Just contact NetGain, and have them E-mail you a motor spreadsheet which
will list all the motor data for your EV specifications.
The Warp 11 motor may not perform as good as the GE 11, because the GE motor
has commentator poles and the field windings are not wound like any other
motors. They only made 6 of the proto type motors that was wound this way.
When I first received this motor (with the EV), GE would not released the
winding data at the time. Anyway I really do not need them, because if ever
I have to rewind this motor, I can blue print it out at that time.
Roland
----- Original Message -----
From: "M.G." <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, September 25, 2006 7:25 PM
Subject: Re: Motors
> I find this statement hard to believe...:) If this is true I have a very
> nice 11.5 inch motor.
> Mike G.
>
> >The 11's will pull twice the torque at 1500 rpm at half the ampere as
> >with a
> >Warp 9 or a ADC 9 which would be the same torque and ampere at about 3000
> >rpm.
> >
> >My GE 11 pulls 175 motor and battery amperes at 60 mph in 3rd gear ratio
> >of
> >5.57:1.
> >
>
>
--- End Message ---
--- Begin Message ---
I have a 288V pack. Per the lists reccomendation I got 2 of the
hienaman breakers
http://www.evparts.com/shopping/product_details.php?code=cb2410
and wired them in series(Also need to pin the handles together) . I have
a zilla 1K and a warp 9 and they haven' tripped at some prety spirited
test runs.
--- End Message ---
--- Begin Message ---
Security code and service code are two completely different things.
Security code won't really stop it from being stolen- just makes it
nonfunctional to the thief unless they can figure out how to get around
the code. The user has to set the Security Code or it will work without
a code, I doubt many people set that feature in the first place. The
Service Code (12321) will unlock diagnostic information, diagnostic
procedures, and calibration procedures.
Actually it's not just that the bumper can trip on weeds. By the nature
of the blade cavity, if you have something like Johnson grass (tall weed
grass) that comes up, if it (or a similar weed) is more than a couple of
inches high, it will push it over but the blades will glide right past
the flattened plant and then it pops back up behind the mower, basically
unaffected.
Neighbors and passers-by have been impressed. No noise, no exhaust, no
clouds of flying grass clippings.
Curiously the birds sometimes worship it, as a god apparently. Mowing
exposes bugs for them to snack on, and unlike a gas mower and operator
they're not afraid of it. So they sit in the same area and even follow
behind it looking for a free meal.
Danny
Michael Perry wrote:
BTW, I don't think you are *supposed* to give out your security code, if
these are built like the earliest units. I forget which... CIA I think...
but one of the branches where security was important. They bought a couple
of these type mowers, battery operated. In *those* at least, the security
code was to keep someone from stealing the mower. (If wheels were lifted off
the ground, the security code was necessary for it to start mowing again.)
Is this different?
--- End Message ---
--- Begin Message ---
There is no reason to put the breaker in the middle of the
pack, unless you want to break the pack in smaller "blocks"
to make it safer to work on (and use the contactors to
break the voltage at the ends).
However, in safety-respect, you cannot always rely on your
contactors as they may get stuck or weld closed, so the
breaker needs to be able to open the full pack voltage
and have a current interruption rate of the max possible
current (think: full-on failed controller, motor blocked)
but most high-voltage DC breakers have like 10,000 Amp
interrupt spec. (Airpax and Heinemann for example)
NOTE that if you plan for a BMS (Battery Management System)
or other facility that is connected to multiple batteries,
then opening the pack can put large negative voltages on
the components and blow them up.
In such case it may be preferably to only break the pack
at the end. For safe working you can always make it
easy to remove a few interconnects to create blocks.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Jake Oshins
Sent: Monday, September 25, 2006 10:16 AM
To: [email protected]
Subject: Safety question
If I build a 288V pack and I want to put a breaker and/or an emergency
cutoff switch in the middle of it, what voltage do those need to be
rated for? Do they need to be able to break the whole pack voltage? Or
half of it? Or some other magic number?
Thanks,
Jake Oshins
--- End Message ---
--- Begin Message ---
Look to see if you have a golf cart place in town, They can generally
handle the simpler EV service and questions. and even parts.
--- End Message ---
--- Begin Message ---
Not planning. The prototype has been running for about 9 months now.
We are currently putting together systems for system trials with a few
companies.
You could only get a lower price by buying in bulk. If the quantity
is high enough, the vendor might even pre-match it at the factory for
you.
On 9/25/06, Dmitri Hurik <[EMAIL PROTECTED]> wrote:
800 cycles, okay, good. So tell me about your project you are planning on
using these cells for. Where can I buy these for $5-$6? I can't find these
on their site.
----- Original Message -----
From: "Jack Murray" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, September 25, 2006 7:16 PM
Subject: Re: IB9000 NiMH Re: Currently most powerful bats or caps available?
> Where do you get confidence that a123 cells have a 2000 cycle life?
> That takes over 6 months to test with 24x7 charge/discharge (if my sons &
> I math is right :)
> Frankly, by the time the NiMH cells are dying in 2-3 years, new battery
> technology and lower prices would almost certainly be the case so you'd
> want to replace them anyway, with some 3500v caps :) so I'm not too
> concerned about cycle life over a lower initial cost. I liken this to
> compact florescents last "3 years", but I replace them within a few months
> in some cases..or I smash them on accident and my "investment" is gone.
> IB says 800 cycles for the D-Cells, did they make it up? Or we trust
> A123, but not IB to give valid numbers?
> Jack
>
> Dmitri Hurik wrote:
>> I apologize about wrong facts about YT. But ok, a Typical NiMH cell doing
>> 800? Not fair comparison either. The typical I've seen on 99% non-ev,
>> low-cost cells such as SubC / D are 400-500 cycles. More costly but
>> better quality will do more(like Saft), but that's not "typical"
>> Example: http://img216.imageshack.us/img216/5936/cyclehy3.gif HED-9000
>> cell, source: Suppo Battery, about 400 cycles.
>>
>> And NiMH manuals I've seen advise AGAINST parallel charging.
>>
>> And I agree with what Mike said:
>>
>> Typically whoever makes a good sub-c is not a candidate for making a
>> good D cell. Rechargable D cells are a long forgotten cell type. So
>> serious testing is the only way you'll know anything.
>>
>> In order to parallel nimh you must be able to separate the strings
>> occasionally for equalizing. So making that sub for a YT is going to
>> be fun.
>>
>> ----- Original Message ----- From: "Edward Ang" <[EMAIL PROTECTED]>
>> To: <[email protected]>
>> Sent: Monday, September 25, 2006 2:42 PM
>> Subject: Re: IB9000 NiMH Re: Currently most powerful bats or caps
>> available?
>>
>>
>>> Dmitri,
>>>
>>> Please check your facts before posting. You are comparing the
>>> theoritical best case on the lead acid with the practical worse case
>>> on the Nimh. It is not only unfair, it is not even realistic.
>>>
>>> 50 Ah at 1C rate for an YT?! You must be dreaming. And, you still
>>> get 500 cycles? I doubt that this is even possible in the ideal lab
>>> condition. I have tested near 200 YT's, none could do more than 45 Ah
>>> even after an extensive break-in. Most could only do about 30Ah if
>>> you do not wake them up slowly.
>>>
>>> For a fairer comparison, a typical Nimh cell could do >800 cycles at
>>> 100% DOD at 1C rate before dropping below 80% of its original
>>> capacity. And, charging them is far easier than charging LiIon. Nimh
>>> batteries are designed to handle some overcharge.
>>>
>>> On 9/25/06, Dmitri Hurik <[EMAIL PROTECTED]> wrote:
>>>
>>>> Well at $5 a piece I get $462 per kwh for these.
>>>> Yellowtops 24ah? Whaat? From the numbers I've seen they are about 50ah
>>>> at 1
>>>> hour rate.
>>>> If they are $160, then I get $266 per kwh for YTs.
>>>>
>>>> And these NIMH cells typically don't last longer than 500 cycles, which
>>>> is
>>>> not really any longer than lead acid. So your NIMH will cost about
>>>> twice as
>>>> much as lead acid. Is it worth the weight savings, but double price?
>>>> Your
>>>> call.
>>>>
>>>> And competitive with A123? I say no. Bare IB9000 cells you say are $5 a
>>>> piece so $462/kwh. You can get A123 cells on eBay for $1350 per kwh in
>>>> DeWalt packs right now. That is not 3-4, more like 2-3 times the cost.
>>>> Then,
>>>> say you actually buy these A123 cells in bulk without those DeWalt
>>>> packs,
>>>> you might have $1000/kwh or less. And then, the IB9000 cells will last
>>>> about
>>>> 500 cycles, where the A123 cells will easily last 2000 cycles according
>>>> to
>>>> a123, and should even last 3000+ cycles, are lighter and way more
>>>> powerful(30C cont and 80C long pulse, 100C short pulse). So the A123
>>>> cells
>>>> actually come out cheaper over their lifetime. And keep in mind these
>>>> are D
>>>> size NiMH cells, which are usually way less powerful than the Sub-C
>>>> cells
>>>> per kg. If you are smart, you should pick A123 instead. No point at all
>>>> in
>>>> these NiMHs. And charging NiMH isn't going to be any easier. They need
>>>> a
>>>> different charging algorithm, unlike the CC/CV of Li-ion and lead acid.
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: "Jack Murray" <[EMAIL PROTECTED]>
>>>> To: <[email protected]>
>>>> Sent: Monday, September 25, 2006 1:42 AM
>>>> Subject: IB9000 NiMH Re: Currently most powerful bats or caps
>>>> available?
>>>>
>>>>
>>>> > Intellect has a new 9Ah NiMH D-cell battery.
>>>> > I haven't seen them mentioned on the list.
>>>> >
>>>> > They can handle 10C discharge (90amps), and 2C (18amp) charge rates,
>>>> > weight is 175g. The key feature is the price, only $5-6 ea!
>>>> >
>>>> > This basically makes them competitive to the lithium A123 M1 cells
>>>> at > much
>>>> > less cost. The M1's are 70g for 2.3Ah at 3.3V, so 280g (4 cells)
>>>> for > 9Ah,
>>>> > the IB9000 weighs 525g for 3-cells at 3.6v, so the M1's are roughly
>>>> > half
>>>> > the weight, but 3-4 times the cost.
>>>> >
>>>> > Compare to a Optima Yellow Top, that is 24Ah C/1, and you guys tell
>>>> me > not
>>>> > to go more than 50% dod, so really just 12Ah, and weigh 20Kg, price
>>>> > is
>>>> > about $160.
>>>> > 20 cells of IB9000 would be 18Ah, weigh 3.5Kg, and cost $120.
>>>> > That is 1/5th the weight and even less cost!
>>>> >
>>>> > I will be testing, and will probably be importing some quantity of
>>>> them
>>>> > if they perform as advertised.
>>>> >
>>>> > Jack
>>>> >
>>>> > Dmitri Hurik wrote:
>>>> >> Super caps will Not give 20 miles.
>>>> >>
>>>> >> Pretty much the most powerful batteries would be www.a123systems.com
>>>> >> already released and other high power lithium-polymer used in RC
>>>> cars.
>>>> >> Should get over 1000 HP, I suppose 2000 HP or more is possible with
>>>> >> increased battery weight.
>>>> >>
>>>> >> ----- Original Message ----- From: "Ryan Stotts" >>
>>>> <[EMAIL PROTECTED]>
>>>> >> To: "EVDL" <[email protected]>
>>>> >> Sent: Sunday, September 24, 2006 4:13 PM
>>>> >> Subject: Currently most powerful bats or caps available?
>>>> >>
>>>> >>
>>>> >>> Any ultra or super caps available that can get ~20+ miles of range?
>>>> >>> What kind of power output?
>>>> >>>
>>>> >>> How about on the battery front?
>>>> >>>
>>>> >>> How much hp can be had from a 348V pack with currently available
>>>> >>> energy storage devices?
>>>> >>>
>>>> >>> Anyone have any inside info on any products that are on the verge
>>>> >>> of
>>>> >>> actually being released?
>>>> >>>
>>>> >>
>>>> >>
>>>> >
>>>>
>>>>
>>>
>>>
>>> --
>>> Edward Ang
>>> President
>>> AIR Lab Corp
>>>
>>
>>
>
--
Edward Ang
President
AIR Lab Corp
--- End Message ---
--- Begin Message ---
Matt Kenigson wrote:
Well folks, it's official. After many sleepless weeks and months of
reading about everyone else's EVs I finally have one of my own!
Congratulation, Matt! Welcome to the club.
We're here for you if you have any questions. And I like the name; I
don't think your daughter can come up with anything cuter, unless she's
under the age of 5.
Jude
--- End Message ---
--- Begin Message ---
David,
Remember the Ford Exploder tire recall?
(a few SUV tires failed from under-inflation and Ford
sued the supplier into recalling millions of tires.)
And how many batteries have actually failed in laptops?
How many laptop batteries have been sold worldwide in recent
years? 200 million? 400 million? More?
The recall would address just a few percent of those.
For the over-discharge quote I referred from memory, so I
do not have a link handy, but I read from a major Li-Ion
propulsion battery manufacturer that they investigated
every failure that lead to their battery not performing
as expected. All failures could be traced back to
over-discharge. I hope someone else on this list remembers
the tests I refer to and post a link to this manufacturer.
(Who is worthy of support, when they are so open about
their failures and publish the test results for all to
learn from.)
Current problems with laptop batteries are due to the
combination of (too) high temperatures inside laptops
(how often do you thing the laptop fan fails? I am in
need of the second replacement right now on the same
laptop that I have for 3 years. How is that for a
statistic and reasonable cause of battery failure?)
and constant charging with the power brick plugged in.
So, indeed the current flurry of failures are all
related to over-charging (and heat) but the vehicular
issues that we are concerned about, usually make
over-discharge more likely as failure mode and my
comment concentrated on that application field,
sorry that I did not indicate the limited scope.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of David Ankers
Sent: Saturday, September 23, 2006 12:36 AM
To: [email protected]
Subject: RE: EVLN(Lithium-ion battery fires concern auto
enthusiasts)-Long
I wouldn't call 4.1 million a limited series? That's for Dell alone and
doesn't count the apple packs.
Did you read the articles that started this thread? It appears obvious that
you did not. You are also flat wrong that "Most Li-Ions die when they are
accidentally over-discharged", most problems happen in the opposite case,
over charging. These issues are not the cause of my concern; my concern is
defective cells that internally short.
I give up. If people aren't prepared to do the research but instead take
manufacture's claims, with zero proof, as reality it is a sad reflection on
the state of critical thinking. Just because it matches what you want to
believe doesn't make it true.
Do the research and you'll see a lot of Lithium cell issues. If it's just
the dodgy Sony cells, what about this IBM fire?
http://gizmodo.com/gadgets/laptops/gizmodo-reader-witnesses-ibm-laptop-catch
-fire-at-lax-201115.php
What about the mobile phones issues as well?
http://www.pcworld.com/article/id,113980-page,1/article.html
Also check the CPSC website and you'll a lot of examples involving Lithium
cells.
Naturally Tesla knows about the risk of Lithium cells, but so did all Laptop
manufactures..... How much Tesla have done to combat this, we only have
Tesla's word about. If some of the worlds leading technology companies,
using much fewer cells have failed to address this, I think it is wise to be
cautious.
I'm actually shocked at the fan boy level of this list, there are legitimate
questions here - that much really is beyond debate and I've backed up my
concerns with verifiable information. To say these concerns are alarmist is
disingenuous, the alarm of the public will obviously come from seeing the
same cells Tesla uses exploding in consumer devices.
I personally am not prepared to dismiss this problem until the Teslas have
been in everyday use for a while. I would much prefer a Tesla with the
Phosphate based cells and I have personally tested the Emoli cells to
failure with a puncture test, over charging and a total short; I did this as
I'm using them in an Electric scooter.
Time will tell what happens, maybe Tesla will switch to a safer cell
chemistry sooner rather than later.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Cor van de Water
Sent: Saturday, 23 September 2006 3:24 PM
To: [email protected]
Subject: RE: EVLN(Lithium-ion battery fires concern auto enthusiasts)-Long
Since Tesla also knows about the Li-Ion vulnerability to
self-destruction, could they have built a protection into
their layered battery pack?
Maybe temp sensors on a real BMS?
Or made sure that they had the proper, not-contaminated
materials in their cells?
Most Li-Ions die when they are accidentally over-discharged
so a good BMS and this does not happen.
Anyway - DELL did not recall a single laptop.
Only a limited series of Sony-made batteries were recalled.
I have several DELL laptops around and even a stack
of spare batteries, from all kinds of dates.
None of the batteries I had were part of the recall.
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of David Ankers
Sent: Friday, September 22, 2006 9:09 AM
To: [email protected]
Subject: RE: EVLN(Lithium-ion battery fires concern auto
enthusiasts)-Long
>> Puncture a stock laptop Li-Ion and it bursts in to flames.
>Good data point. You have done this, right? So it is not a myth?
Yes, I have done this and I've done it with Lithium Polymer cells as well.
You might be one of the few using Li-Pos in an EV but there are hobbies that
have been using them much much longer. There are videos around of these
tests. I'm sure there is one on the valance site even, I think they start
off shooting the cells with a bullet, that's a little extreme, however later
they show a simple laptop cell puncture test. Kaboom.
Here ya go: http://www.valence.com/SafetyVideo.asp
Now a polymer:
http://www.rcgroups.com/forums/showpost.php?p=5800338&postcount=4
>> Two reasons why I have not ordered a Tesla, first they are left hand
>> drive but I would not buy a car using stock laptop cells.
>> All it takes is one of the 7000 cells to be faulty and, you will be
>> killed.
> Really? One cell faulty and you will be killed? This seems kind of
> extreme.
> You know this right, it is not one of those lithium myths you were
> talking about?
Stop being a dick. Yes, it's a bit hyperbolic but I am not going to risk it,
at best very badly burned. There is a small problem called thermal run-away
and you just can stop it once it reaches critical mass. There are numerous
videos around and I can assure you that others on this list are concerned
about the same issue with the Tesla.
>> BTW Do you drive a gas car? Is gasoline flammable or even worse,
>> explosive? (Oops. Sorry, that was a bit inflammatory<G>.)
This has been debunked as a false analogy a long time ago. The evidence of
everyday life obviously bares this out easily. You are claiming that
Gasoline just spontaneously explodes from just sitting in the tank? That's
ridiculous. However, what we are seeing in everyday life is faulty laptop
cells spontaneously exploding:
http://www.gizmodo.com/gadgets/laptops/dell-laptop-explodes-in-flames-182257
.php
Dell has recalled a couple of million laptops recently due to faulty cells
that could have an internal short. Apple has done this twice and many more
companies as well. As you can see from the picture in that article, it's not
such a small fire and that is with 8 cells, now, imagine that with 7000.
These are Cobalt Oxide cells as Tesla is using. The laptops have a state of
the art BMS, didn't help as the issue was an internal cell short.
>> Hey Cliff, you were so lucky in that incident (although that cell would
>> have been toast, you caught that just in time.
> Sadly, it has happened more than once. I guess I must just be blessed
> with luck. Or maybe the cells are not prone to bursting into flames.
> This is what Kokam claims.
> http://www.kokam.com/english/product/kokam_safety_02.html
Kokam still have the same problems with larger packs failing? Pity given
they cost a lot. Kokam claims a lot and always has, they still 500 cycles
pack life! Polymer based cells are safer than Ion but they are still metal
oxide based, so you have Lithium and an oxygen in the same little package.
Remember the fire triangle from school? All that is missing is heat. Not
hard to figure out is it? Hence when you discharged that cell after it
failed and it got warm why I stated you were lucky. Then again, having the
car filling with thick white smoke isn't exactly lucky either. I get the
distinct feeling that you haven't seen what can happen in a worse case
scenario when a cell fails.
But here's lots of evidence for you from the rc-world + videos.
http://www.rcgroups.com/forums/showthread.php?t=209187
List of incidents starts at post 4. You'll see even from small RC packs
people have lost their house and also cars. These are all with the safer
Polymer packs (some being Kokams) and of course only from people that use
that one site. Some are human error, some are not.
Listen, I love the Tesla and I like where Lithium technology is going to but
I am worried that all it takes is one Tesla to have an issue and certain
vested interests will use this to demonise the EV as unsafe. In the first
run of Tesla's there is going to be 700,000 Cobalt based Li-Ion cells on the
road, what's the chance of just one being bad? I wish they would use the
phosphate based cells and I think it has to be a cost issue although one
mishap could cost them very dearly.
You might be one of the first to use Li-Po packs in an EV but I think you
made the mistake of thinking that nobody else has bothered working with
them. In RC we have been using them for several years and in fact if EV'ers
used some of that information, there would a lot less Thunder Power cells
sold to the EV crowd.
Yes, there are a lot of myths and guess work on this list; it is exactly the
same kind of information that was seen when Li-pos were first being used in
RC.
--- End Message ---
--- Begin Message ---
At 08:46 PM 25/09/06 -0400, Mike (the new guy) wrote:
<snip>From some of the reading I've been doing AC seems to be more
efficient than
DC in an EV.
G'day Mike, and all
Aaah, the good old AC vs DC debate.
In a nutshell: DC is usually lower voltage and can be considered similar to
computers in the manner you can "mix and match" bits from all over and get
them to play together. DC is very good for those who like to play with
their EV, tweak this and that, build using bits on the cheap and upgrade later.
AC is usually an engineered package, generally used by people with an
engineering bent, who want to specify then build a competent and reliable
EV that once built they can just drive. AC components are usually packaged
and integrated as a system, Siemens warranty theirs for 10 years, but you
pay for it in two ways: dollars up front and being locked into their package.
In terms of overall efficiency, if you are in stop-and-go traffic, AC can
give anything up to 10 percent more range from the regen capability that DC
usually lacks, but if you are out onto the highway and steady speed
travelling, there will be almost no difference.
I see the AC vs DC debate coming back to: what type of person are you? do
you like to scrounge and fiddle, find a better bit and upgrade things, save
for a better controller, etc., or do you want to design, specify, build
then drive your EV?
If you like to play, then go DC, if you like to "engineer" things (or if
you want a very reliable EV that other people can drive in complete safety)
then AC is probably your route.
Hope this helps
Regards
[Technik] James
--- End Message ---
--- Begin Message ---
The biggest problem I see with NiMH was the 1C charge rate.
These new IB cells have a 2C charge rate. That is half the time.
Those F-cells have 3C discharge rate, the IB cells are 10C, three times
more power.
Jack
Death to All Spammers wrote:
800 cycles, okay, good. So tell me about your project you are
planning on
using these cells for. Where can I buy these for $5-$6? I can't find
these
on their site.
F-cells seem like the best bet -
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1039 -
these folks also sell for $2/cell less on eBay.
--- End Message ---
--- Begin Message ---
> For instance I understand that at the lowest budget level I'd be
looking at
> 6-8K, but since this is a "long term" project I can spread the costs out
> over the course of however long it takes.
Long term as in taking a long time to finish, or long term as in
completing increasing levels of performance capabilities in steps?
> So let's say for instance I was willing to invest 15-20K in this,
are there
> better options than the standard 9v DC motor and 6v sla batteries.
>
I don't think EV motors come in 9v unless they're RC! You'd need a 72V
or higher motor, and run at least a 120v system for minimum
performance. SLA batteries come in a 6v size, but are most EVs use the
12v ones - Optima, Orbital, Hawker, Concorde and several other brands.
--- End Message ---
--- Begin Message ---
--- Michael Trefry <[EMAIL PROTECTED]> wrote:
> Thanks to those who took the time to welcome me, and
> those who emailed me
> personally.
>
> I'm still trying to figure out exactly how I'm going
> to build this, although
> I think I'm sold on the 914 (I Love those cars!)
>
> I may still go for the kit offered at evparts or
> electroauto, but I want to
> understand my options before I nail myself down to a
> specific technology.
>
>
> >From some of the reading I've been doing AC seems
> to be more efficient than
> DC in an EV.
yes-- A) you get regen braking, which can add up to
25% range
B) higher voltages = lower amps = greater efficiency.
>
> Are there disadvantages to using an AC system?
-Cost.
-Available systems sometimes not as adaptable to
existing transmission schemes.
-Decent performance only when using high voltages, so
how to get those voltages: 12V hawkers (AGM batteries)
need careful charge regulating, or they die early.
That incurs _additional_ costs, but it is _do_ able.
Is it
> more complex,
> expensive? Are there other limitations?
>
> It looks like 6v fla batteries are pretty standard,
> but all this talk I'm
> seeing about batteries is making me curious about
> what the best
> cost/performance battery solution is.
I take 8V due to increased performance but same
lifespan as 6V (or close to it).
>
> Ideally I'd like to get at least 60 miles on a
> charge, be able to get up to
> at least 85mph and have some decent acceleration. I
> think a 0-60 in 20
> seconds car would drive me insane.
>
Ahhh, but the 0-30 is WAAAAAAY sweet!!! It's that
last 10 mph that is the equalizer... I can lay rubber
without trying for the first 50' or so.
My Civic at 144 performs like stock, but the torque
curve is much different than a gas burner.
RE: top speed, 3rd takes me to 72. Haven't tried
4/5th gear.
Converting a gen. 5 Honda Civic? My $20 video/DVD
has my '92 sedan, as well as a del Sol and hatch too!
Learn more at:
www.budget.net/~bbath/CivicWithACord.html
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?
Are you saving any gas for your kids?
__________________________________________________
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--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
I had the impression that 13.5V was a good standby/float voltage
for 12V AGMs?
13.5v is a safe, simple, KISS "float" voltage for a 12v lead acid
battery. It's easy and cheap to implement, which is why it's almost
universally used.
However, it actually slightly overcharges the battery continuously. It's
making no allowances for battery temperature, age, or condition. If you
leave the battery at 13.5v continuously, it will slowly dry out and die.
Typical life is 1-3 years.
The battery lasts longer if you fully charge it, and then turn the
charger OFF. Start the charger again periodically (every few weeks or
months as needed). You can more than double their life that way.
--
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 ---
Since this does not seem like the typical AC vs DC debate, I thought I would
weigh in. One thing to note though: we are not really comparing "purely"
AC to DC motors, but comparing the currently available hobbyists AC and DC
systems. So here is my pro and con list based on what we can readily
purchase today:
AC
- regen
- can use higher voltages - smaller wires, but more batteries and more
connections
- wider power band
- can hold on hills without causing brush burnout
- somewhat more expensive
- Siemens, MES and Solectria are all AC systems
DC
- most powerful available to hobbyists (current leader in drag racing cars)
- can get higher power systems cheaper
- entry level is inexpensive on a weight & power basis
- lower voltage means less batteries and connections, but bigger wires,
fuses, contactors and breakers
- huge torque off the get go
- Warp and ADC are DC motors
- ADC and Zilla are controllers
Then there is looking at manufacturers:
Siemens AC motor/controllers
- OEM quality, water proof, well built, made for automotive applications
- liquid cooled
- programmable
- easy to set up
Zilla Controllers
- made for EVs
- programmable
- can drive dual motors for electronic transmission
- very powerful
- liquid cooled
Warp/ADC Motors
- the "standard" dc motor
- air cooled
- fork list motor used successfully in many, many EVs
Hmm, well that should get a few replies!
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 Michael Trefry
Sent: September 25, 2006 5:46 PM
To: [email protected]
Subject: AC vs DC?
Thanks to those who took the time to welcome me, and those who emailed me
personally.
I'm still trying to figure out exactly how I'm going to build this, although
I think I'm sold on the 914 (I Love those cars!)
I may still go for the kit offered at evparts or electroauto, but I want to
understand my options before I nail myself down to a specific technology.
>From some of the reading I've been doing AC seems to be more efficient
>than
DC in an EV.
Are there disadvantages to using an AC system? Is it more complex,
expensive? Are there other limitations?
It looks like 6v fla batteries are pretty standard, but all this talk I'm
seeing about batteries is making me curious about what the best
cost/performance battery solution is.
Ideally I'd like to get at least 60 miles on a charge, be able to get up to
at least 85mph and have some decent acceleration. I think a 0-60 in 20
seconds car would drive me insane.
Suggestions anyone?
Thanks,
Mike (the new guy)
--- End Message ---
--- Begin Message ---
Mike,
This may be a good basis for a plug-in Hybrid modification.
Prius has its engine and motors (2 AC motors) tightly integrated
with the onboard computers, so if you wish to make it a DC EV
than it should be poossible, but there are many more choices
that are available at way lower (donor car) cost. Prius is a
very much wanted car, so you pay a premium, even for a salvage.
BTW the "automatic" part of a Prius is the all-electric control
of the torque converter with a sort of built-in differential
between the two electric motors, engine and wheels.
If you take the engine out, you will also lose the AC motors and
the transmission - it's all integrated, so you then need to find
a transmission from another car.
I suggest to look into the plug-in hybrid concepts and read up
on the concept from the available online info such as the
Prius+ yahoo group and the supplier of the kit, plus the efforts
from some list members that are regularly posted here.
Success,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of mike golub
Sent: Monday, September 25, 2006 5:03 PM
To: [email protected]
Subject: toyota prius donor car?
Hello
There was a disscussion about how a Hybrid car would
be a good donor car to be 100% EV. (I think?)
I was looking at 2005 Toyota Prius that is going on
auction with front end damage. Looks like an
automatic.
Could you just take the motor out and put a 9" DC
motor, or are you better off just trying to get some
more NIMH battery packs, and a charger? And never put
gas in?
Car seems pretty heavy for its size.
How much are the batteries worth? Car has 15K miles.
thanks
Michael Golub
1986 Toyota PU 120VDC 9"WarP
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--- End Message ---
--- Begin Message ---
So? What is the message here?
3V drop on a 3000V supply means you lose 0.1% in power.
That is 100 Watts in a 100kW controller. Not bad.
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Evan Tuer
Sent: Monday, September 25, 2006 9:41 AM
To: [email protected]
Subject: Re: "Ultracapacitor-Battery" blows away Current Lithium-Ion
Battery
On 9/25/06, Rich Rudman <[EMAIL PROTECTED]> wrote:
> I just found this post from 2 weeks ago...
>
> lets see.. We can get 3500 and 6500 volt IGbts..from some where .
> Man I don't want to know what the votlage drop would be... like 6 volts I
> bet... LOT.!!
"The new 4.5KV devices have Vce(sat) = 3.3V@ 125 degrees centigrade"
http://www.pwrx.com/pages/newsflash/press_release.asp?file=270%2Ehtm
Dead easy right? ;)
--- End Message ---
--- Begin Message ---
See I told you I know next to nothing.
So these DC 9s are not 9v, but 9 What? Amps? Inches?
I meant long term as in long time to finish. I'm not under any illusion that
I'll whip this thing together in 6 days as the kit suggests is possible. I'm
thinking it will likely take me 6 months or more of weekends. Not because of
the work involved necessarily, but because of my cautious nature of diving
into a world I know nothing about.
On the batteries, I assumed 6v were standard because I read that on the
electroauto.com site.
See this is what I mean by not knowing if what I'm reading is up to date.
That site said 96v systems were typical.
So to get a minimum of a 120v system, does that mean 10 x 12v batteries?
Is there a recently published, up-to-date book on the subject? I see plenty
of books 10 years or older, which I'm sure have good information and will
help me get a better understanding, but one that covers the latest
technology on the subject would be preferable.
Or have there really been no advances in the field in the last 10 years?
Sorry if this seems like an inquisition :) I just want to start in the right
place.
Thanks!
Mike
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Death to All Spammers
Sent: Tuesday, September 26, 2006 12:06 AM
To: [email protected]
Subject: Re: AC vs DC?
> For instance I understand that at the lowest budget level I'd be
looking at
> 6-8K, but since this is a "long term" project I can spread the costs out
> over the course of however long it takes.
Long term as in taking a long time to finish, or long term as in
completing increasing levels of performance capabilities in steps?
> So let's say for instance I was willing to invest 15-20K in this,
are there
> better options than the standard 9v DC motor and 6v sla batteries.
>
I don't think EV motors come in 9v unless they're RC! You'd need a 72V
or higher motor, and run at least a 120v system for minimum
performance. SLA batteries come in a 6v size, but are most EVs use the
12v ones - Optima, Orbital, Hawker, Concorde and several other brands.
--- End Message ---
