EV Digest 7005
Topics covered in this issue include:
1) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla
Roadster Battery Pack)
by Dan Frederiksen <[EMAIL PROTECTED]>
2) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla Roadster
Battery Pack)
by "Shaun Williams" <[EMAIL PROTECTED]>
3) My power consumption
by "Richard Acuti" <[EMAIL PROTECTED]>
4) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla
Roadster Battery Pack)
by Dan Frederiksen <[EMAIL PROTECTED]>
5) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla Roadster
Battery Pack)
by Marcin Ciosek <[EMAIL PROTECTED]>
6) Re: Building LiFePO4 packs from many, many 18650s
by Ian Hooper <[EMAIL PROTECTED]>
7) Jay Leno reviews the Tesla Roadster
by "Claudio Natoli" <[EMAIL PROTECTED]>
8) Re: My power consumption
by "Peter VanDerWal" <[EMAIL PROTECTED]>
9) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla
Roadster Battery Pack)
by Dan Frederiksen <[EMAIL PROTECTED]>
10) Re: Ideal EV configuration for my situation?
by [EMAIL PROTECTED]
11) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla Roadster
Battery Pack)
by Marcin Ciosek <[EMAIL PROTECTED]>
12) Re: Building LiFePO4 packs from many, many 18650s (was Re:
Tesla Roadster Battery Pack)
by Bill Dube <[EMAIL PROTECTED]>
13) conversion question
by "Tom S." <[EMAIL PROTECTED]>
14) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla
Roadster Battery Pack)
by Dan Frederiksen <[EMAIL PROTECTED]>
15) Re: conversion question
by "Roland Wiench" <[EMAIL PROTECTED]>
16) RE: Adding electric assist to a surrey bike
by "Michael Wendell" <[EMAIL PROTECTED]>
17) limiting wire
by [EMAIL PROTECTED]
18) RE: Another EV smile
by Jeff Mccabe <[EMAIL PROTECTED]>
19) Re: Building LiFePO4 packs from many, many 18650s
by Ian Hooper <[EMAIL PROTECTED]>
20) Re: limiting wire
by "Zeke Yewdall" <[EMAIL PROTECTED]>
21) Re: Another EV smile
by [EMAIL PROTECTED]
22) Re: Building LiFePO4 packs from many, many 18650s
by Marcin Ciosek <[EMAIL PROTECTED]>
23) Re: Building LiFePO4 packs from many, many 18650s (was Re: Tesla Roadster
Battery Pack)
by Marcin Ciosek <[EMAIL PROTECTED]>
24) Ideal EV configuration for my situation?
by "Matthew Chan" <[EMAIL PROTECTED]>
25) Re: Ideal EV configuration for my situation?
by "George Swartz" <[EMAIL PROTECTED]>
--- Begin Message ---
Do we have any prices on bulk A123 cells?
has anyone ever been able to buy some?
Jukka Järvinen wrote:
Bill.. Do you have any info on A123s how they die after overchareged
repeatedly ? How many cycles are needed with overcharging to reduce
the cell capacity and/or increase the internal resistance to unusable
levels?
--- End Message ---
--- Begin Message ---
A was kindly given a quote by the A123 Systems folk a couple of months
ago for 1500 cells but in the spirit of a good conspiracy theory, on
which some appear to thrive, I can't possibly tell you their price...
:-)
However, a quick search for "DeWalt 36V" prices at eBay will give you
the correct answer (with the bonus of a 10 "module" battery balancer
thrown in!).
Shaun
www.electric-echo.com
On 7/9/07, Dan Frederiksen <[EMAIL PROTECTED]> wrote:
Do we have any prices on bulk A123 cells?
has anyone ever been able to buy some?
--- End Message ---
--- Begin Message ---
Ok, I have some more numbers to add to my power consumption curve for a '74
bug with 16, 8v batteries @69 lbs. each:
Last night, when I went to Annapolis, I averaged 33 mph @ 65 amps * 135
volts= 8.8kW (rounded up) 1st gear.
This morning's commute on the highway I averaged 55 mph @ 90 amps *130
volts= 11.7kW. 2nd gear.
Like I said, without an E-meter it's kind of hard to be perfectly accurate
due to all the low-grade hills around here. My inbound commute is definitely
an overall uphill pull but I used a pretty level stretch to get the 11.7kW
number.
I have good, new tires and the alignment is straight. I'd like to regrease
my bearings and replace the gearbox oil. I also intend to swap out the
Subaru seats for light, polymer racing seats as well as all fenders, trunk
and deck lids for fiberglass replacements. The body panels alone will save
me almost 200 lbs. Maybe that'll help a little.
Rich A.
_________________________________________________________________
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_2G_0507
--- End Message ---
--- Begin Message ---
I'm not sure I follow that reasoning but please tell me the price
Shaun Williams wrote:
A was kindly given a quote by the A123 Systems folk a couple of months
ago for 1500 cells but in the spirit of a good conspiracy theory, on
which some appear to thrive, I can't possibly tell you their price...
:-)
However, a quick search for "DeWalt 36V" prices at eBay will give you
the correct answer (with the bonus of a 10 "module" battery balancer
thrown in!).
Shaun
www.electric-echo.com
On 7/9/07, Dan Frederiksen <[EMAIL PROTECTED]> wrote:
Do we have any prices on bulk A123 cells?
has anyone ever been able to buy some?
--- End Message ---
--- Begin Message ---
Dan,
how many do you need ? Do you need them welded together or you are able to do
it by yourself.
It can take a bit long but we can order a "few" extra and sell you as complete
pack.
Marcin
On Monday 09 July 2007 11:06:48 Dan Frederiksen wrote:
> Do we have any prices on bulk A123 cells?
> has anyone ever been able to buy some?
--- End Message ---
--- Begin Message ---
You can buy DeWalt 9360 packs for about US$100, and they have 10x M1
cells in them, so it would seem US$10/cell is about the going rate.
Or US$1.43/Wh, which is pretty expensive even for LiFePO4s. But then
with 70C on tap it's only 2 cents per watt of power, which is rather
good - i.e it might be the cell to go for if you are drag racing. But
I was hoping decent range by using a ~15kWh pack, which makes them
just a little out of my price range!
I'm currently leaning towards the PHET PE1150s (their high-power
18650 cell). Not quite as high power as A123s, but still very good
(20C+ no worries) and around half the price per watt hour.
And rather impressive cycle life. They sent me a datasheet for the
PE1150 which included lab results from cycle tests. 2C charging and
*10C* discharging, and the cells lose 20% capacity in ~800 cycles.
That's cycling at 10C discharge!! So, if I absolutely thrash heck out
of the car for about 5 years, I'd STILL have 80% pack capacity left ;)
(FYI at 2C charge and 4C discharge the cells hit 80% after 1750
cycles. Which is still way above average EV charge/discharge rates,
and represents maybe 10 years of use.)
They're looking good.
-Ian
On 09/07/2007, at 7:16 PM, Dan Frederiksen wrote:
I'm not sure I follow that reasoning but please tell me the price
Shaun Williams wrote:
A was kindly given a quote by the A123 Systems folk a couple of
months
ago for 1500 cells but in the spirit of a good conspiracy theory, on
which some appear to thrive, I can't possibly tell you their price...
:-)
However, a quick search for "DeWalt 36V" prices at eBay will give you
the correct answer (with the bonus of a 10 "module" battery balancer
thrown in!).
Shaun
www.electric-echo.com
On 7/9/07, Dan Frederiksen <[EMAIL PROTECTED]> wrote:
Do we have any prices on bulk A123 cells?
has anyone ever been able to buy some?
--- End Message ---
--- Begin Message ---
Hi all,
don't think this has been posted before, and his articles do tend to generate
interesting follow up discussion.
http://driving.timesonline.co.uk/tol/life_and_style/driving/new_car_reviews/article2036260.ece
http://tinyurl.com/yq8udc
"in the real world most of the fun is between 40mph and 80mph, where you put
your foot on it."
Someone get that man a short ride in a certain white Datsun. :-)
Cheers,
Claudio
--- End Message ---
--- Begin Message ---
Hmm, the 55mph figures seem good. Perhaps you are just running the motor
at a poor point in it's efficiency curve? 33mph in 1st gear sounds like
you are really winding out the motor, perhaps it would be more efficient
in second gear?
> Ok, I have some more numbers to add to my power consumption curve for a
> '74
> bug with 16, 8v batteries @69 lbs. each:
>
> Last night, when I went to Annapolis, I averaged 33 mph @ 65 amps * 135
> volts= 8.8kW (rounded up) 1st gear.
> This morning's commute on the highway I averaged 55 mph @ 90 amps *130
> volts= 11.7kW. 2nd gear.
>
> Like I said, without an E-meter it's kind of hard to be perfectly accurate
> due to all the low-grade hills around here. My inbound commute is
> definitely
> an overall uphill pull but I used a pretty level stretch to get the 11.7kW
> number.
>
> I have good, new tires and the alignment is straight. I'd like to regrease
> my bearings and replace the gearbox oil. I also intend to swap out the
> Subaru seats for light, polymer racing seats as well as all fenders, trunk
> and deck lids for fiberglass replacements. The body panels alone will save
> me almost 200 lbs. Maybe that'll help a little.
>
> Rich A.
>
> _________________________________________________________________
> http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_2G_0507
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
thanks for offering but I'm not ready to order yet. I would like to know
the price potential before I decide on a plan but it would be in the
1000cell neighborhood.
are you buying a lot so you can get them for less than the 10$ retail price?
if dewalt retailers can sell packs with electronics and casing for 10$
per cell I'm guessing DeWalt didn't pay 10$ themselves. perhaps below 5$.
also if battery balance allows I think it would be a great help if
someone could sell packs of 10x10 or 10x20 cells (36V 23Ah or 46Ah) so
others could combine them easy like we do lead acid batteries. is that
something you could do?
the more I think about these cells the more it looks like they could
sweep away lead acids. if only A123 wouldn't be so obtuse about sales of
less than a million cells at a time. Ironically they cater to the hobby
RC crowd which is extremely low volume.
Dan
Marcin Ciosek wrote:
Dan,
how many do you need ? Do you need them welded together or you are able to do
it by yourself.
It can take a bit long but we can order a "few" extra and sell you as complete
pack.
Marcin
On Monday 09 July 2007 11:06:48 Dan Frederiksen wrote:
Do we have any prices on bulk A123 cells?
has anyone ever been able to buy some?
--- End Message ---
--- Begin Message ---
Hey Matt,
Good to see you did alot of research ahead of time and have a pretty
thought out plan. You can consider me a newbie also but have been on the
list for a while and in the middle of my conversion, also having learned a
bit from the experienced guys maybe I can help with your questions.
I think you will want DC. The way I look at it is that you can take a DC
motor and hook it directly to batteries and get down the road, in a manner
of speaking. AC systems required high voltage, in the order of 200v and up
is common. Maybe not the rule? Also it requires a VERY expensive
controller. To handle hundereds of volts and amps its a little complicated
and costly. DC systems can also have regen. Not as common and you have to
pay a little more but with a compound (sepex) motor and controller its
possible. As far as batteries, I am using AGM because I want a fast car
with short range and AGM is known for its high current capabities. I would
suggest flooded Pb because they are cheaper, give a long life if
maintained. I am actually interested in your plan to incorperate a
microcontrller. Maybe I would suggest a diffent donor car. Don't use one
thats old and ragged out. You still have tires, wheel bearings, trans, and
interior to think about. Look in the local trading post, and find an older
car thats cheap but still looks good. When I restore a car I pick a sporty
car that I actually really like. You will spend alot of time on it so buy
your dream car and you won't loose interest. I hope this helps a little
and I haven't given you any wrong information.
Paul
--- End Message ---
--- Begin Message ---
A123 prices are indeed way below 10$, even below 5$ but they are really hard
to get.
I was able to get far better contact with people from PHET and their cells are
at the same level of quality (which was confirmed by HydroQuebec - owner of
LiFePO4 patent) as A123.
Anyway, we can provide welded and wired blocks of any number of cells in
parallel (machine made welding) as well as BMS customized for proper
construction. Right now I'm finishing test of 42P43S 18650 LiFP cells on test
bench and right after the test are finished we will put it into our car and
give it to testing company.
In my personal opinion - using big capacity cells or small ones in parallel
gives similar results, but we will see after first 100 or 200 cycles.
Marcin
--- End Message ---
--- Begin Message ---
Overcharging can cause them to vent. Very, very severe
overcharging can overwhelm the vent and can possibly cause them to
burst. I have never done either, so I have no direct experience or
data. The loss of electrolyte will cause the cell to lose capacity
and to go up in resistance. Since we do not plan on ever overcharging
cells, we really have no need to know the degree or rate of degradation.
Any amount of overcharge will reduce capacity and increase
resistance. That is why you must have a BMS to get more than a few
cycles from Li-Ion cells of any type or brand.
It is like buying a gerbil, but no food for it, and then
complaining to the pet store when it dies in a week. You have to feed
the gerbil or it will die. You have to have a BMS for Li-Ion cells,
or they will die too.
Bill Dube'
At 12:11 AM 7/9/2007, you wrote:
Bill.. Do you have any info on A123s how they die after overchareged
repeatedly ? How many cycles are needed with overcharging to reduce
the cell capacity and/or increase the internal resistance to unusable levels?
I'm curious.
I feel a bit odd to read these comments since I have thought people
would like to get long lifetime out of these cells. Drag racing
might be a different thing. But has the safety been always the only
thing you've been worried about ?
What I see all the time is people comparing the prices. How much
more expencive than SLAs. How much longer life time is needed to
compensate the expence... etc.
For what I have witnessed is that the LiFePO4 cells will get
crappier on every cycle if overcharged up to say 4,7V/ cell. After
few dozen of these cycles you have already some cells which are not
usable anymore.
Is this not the same case with A123s ?
If not.. Then those cells are extremely neat things.
-Jukka
Bill Dube kirjoitti:
If you use decent quality cells, you can parallel them with no
worries. Crappy cells are going to be more trouble than the money
you might save. You will spend a lot of time and money on the BMS
for crappy "flame-thrower" type cells because for safety reasons
you must protect them over heating, over voltage, and under voltage.
If you pay more for the cells, and use high-quality FePo
cells, then many of your BMS complications go away. The BMS
becomes much, much less critical to because the cells don't burst
into flames if they are mistreated in some minor way.
You would be smartest to build a small pack (like for a
scooter, or small motorcycle) and try out your ideas on a small,
inexpensive, scale. Why trash a huge expensive pack to just to
learn a lesson (or two)?
Bill Dube'
At 09:45 AM 7/5/2007, you wrote:
I'm doing something similar, and one suggestion thrown around on
this list was to fuse each sell, so that if one failed short, it
would just be taken out of the "set" of 23 in parallel. Fuse would
be via a properly sized nickel welded tab. But someone pointed out
that failure could be via reduced capacity, or as a resister
instead of a short. Basically reducing one module of 23 cells.
You'd have to monitor this and manually remove the offending cell
before the other 22 parallel cells are destroyed. Or monitor each
cell and remove the offending cell from the circuit. Another idea
thrown around was to monitor cells in series, maybe 4 in series,
you'd get out of balance conditions in those 4 cells, but that
would reduce the number of cells you'd need to monitor. Well, not
sure what is the best method, each one seems like a compromise
except monitoring each cell.
- Tony
----- Original Message ----
From: Ian Hooper <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Thursday, July 5, 2007 8:54:38 AM
Subject: Building LiFePO4 packs from many, many 18650s (was Re:
Tesla Roadster Battery Pack)
Speaking of battery packs..
It seems ThunderSky's prices have gone up about 25% in the last 2
months, which means they've lost most of their cost advantage over
PHET (and others), and with all this talk of dodgy business
practices, it's given me reason for pause.
So once again I'm entertaining the idea of building a pack from
18650s (yes, what a lot of work..!)
I believe the Tesla pack has modules of 99 cells in series, with 23
of these modules connected in parallel. So no single cells are
explicitly paralleled, and if capacities don't match exactly well
it's averaged out over the 99. Great way to do it.
But this requires BMS monitoring of each cell individually, which is
just too much work for me!
So can anyone think of any showstopper problems with just hooking up
modules of 23 cells in parallel, and then wiring 99 of the modules
together in series. Then I'd only have 99 voltage levels to monitor.
(My actual numbers would be different but I'm using Tesla's numbers
for comparison.)
Seems to me the biggest problem would be the lowest common
denominator effect, i.e the groups of 23 would only be as good as the
weakest cell. Oh and if one cell shorted out, that could be rather
catastrophic I guess.
Thoughts?
-Ian
On 05/07/2007, at 11:19 PM, Joseph T. wrote:
> The Tesla Roadster battery pack has 6,831 cells. The Tesla Roadster,
> I've heard, is supposed to be 375 volts. Hmm...Lithium Ion batteries
> are rated at 3.6 nominal voltage. So....3.6 volts times 6,831 cells
> obviously doesn't equal 375 volts!!! What's going on here?
--- End Message ---
--- Begin Message ---
Hi everyone,
I have a question, what is best ratio of a conversion car without batteries, to
batteries, all other things being equal? For instance, 2000lbs of car without
batteries, to 1000lbs of batteries, would be a 2/1 ratio.
Tom Sines
________________________________________
PeoplePC Online
A better way to Internet
http://www.peoplepc.com
--- End Message ---
--- Begin Message ---
Marcin Ciosek wrote:
A123 prices are indeed way below 10$, even below 5$
I love you so much :) but seriously that's very nice to know because at
sub 5$ I think we start to hit the deep cycle lead acid pricing per kWh
and at that point there is no contest. that's really good to hear. nice
to hear that PHET can do as well. by quality do you also mean same cycle
life, power and efficiency?
let's imagine a small series production (100-200) of for instance packs
of 10series x 16parallel (with welds able to handly the power of the
cell) could you give a rough pricing on such packs?
If you can, I really think you should offer that as an off the shelf
product rather than wait for custom orders because I think many wait for
off the shelf and dread custom commitment. even if it is custom behind
the scenes.
if you can this could in a very real sense be a revolution. affordable
super-car lithium. I think a LOT of people outthere are dying to get rid
of some lead
Dan
--- End Message ---
--- Begin Message ---
Hello Tom,
That's about right for long range. If a person is more interested for a
range of about 1500 feet, than the lightest high power battery may be best.
My first EV without the battery pack weigh 3950 lbs and with a 3600 lb
battery pack which consist of 90 each 300 AH lead cobalt cells that was
about 19 inches high to the top of the Hydrocell cap.
This unit could go 92 mph with a range of about 78 miles at 100% DOD. A
demo drive was done to see how far this EV could go in 24 hours which the
target distance was 1000 miles, it went 1056 miles in 24 hours which is a
average of 44 mph.
The EV stop about every hour for a very high power quick charge of 200 to
300 amps for about 15 to 20 minutes. They only had to replace a 25 amp diode
during this run.
The charging stations are as large commercial pad mount transformers or a
37.5 KW 3 phase motor generator that was pull by another EV of the same
type.
These EV's where the only ones that won the Great Electric Car race back in
1975 by EFP.
Search and Look it up.
Roland
----- Original Message -----
From: "Tom S." <[EMAIL PROTECTED]>
To: "ev list" <ev@listproc.sjsu.edu>
Sent: Monday, July 09, 2007 7:31 AM
Subject: conversion question
>
> Hi everyone,
>
> I have a question, what is best ratio of a conversion car without
> batteries, to batteries, all other things being equal? For instance,
> 2000lbs of car without batteries, to 1000lbs of batteries, would be a
> 2/1 ratio.
>
> Tom Sines
>
> ________________________________________
> PeoplePC Online
> A better way to Internet
> http://www.peoplepc.com
>
>
--- End Message ---
--- Begin Message ---
> I recently purchased a used surrey bike from the Golden
> Gate Park bike rental shop. It looks almost *exactly*
> like this model:
>
> http://www.surreycompany.com/images/OnlineSurrey_000.JPG
>
> I'm looking for a way to add electric assist. ...
for ideas on how to do this, you may want to visit http://cleverchimp.com/.
this guy uses his electric assisted bike to do everything. two kids, no car,
everything by bike.
anyway, he started a company selling electric assisted bikes, or kits or
somehting. his blog is great.
m.
--- End Message ---
--- Begin Message ---
analogy then question.
if i have to get 100 people out of a room but there is only one door, the
"CURRENT" of people is limited by the door.
So, in my EV I am upgrading to 2/0 cable with clamp on connectors as
opposed to the 1/0 cable with lug end connectors.
It'll be like 2 doors instead of 1 (less resistance).
The question is, If I have one or two 1/0 cables or one lug end
connector., does that make the whole loop as if it were 1/0 or the I^2/R
equation means I only loose a little of voltage whereas with all 1/0
cabling I loose ALOT of VOLTAGE?
also, what do you do when you forget to put the heat shrink on a few of the
cables?
do you split the 2/0 heat shrink, and then put overtop of it the size heat
shrink that will slide over the clamp?
gracias,
Ben
--- End Message ---
--- Begin Message ---
Thanks,
Man my foot is getting heavy!
--- keith vansickle <[EMAIL PROTECTED]>
wrote:
> Good job Jeff. Keep us posted on performance as you
> get her broke in.
>
> kEVs
>
>
> ---Original Message-----
>
> > Subject: Another EV smile
> >
> > Well my 928 is finally on the road! It took its
> > maiden voyages on Wednesday.
> > Thanks to everyone on the ev-list for your help.A
> > few
> > that have helped directly are , Cor van de Water,
> > Bob
> > Bath for pointing me in the right direction. Most
> of
> > the time I remained in lurk mode and used many
> great
> > ideas from the very knowledgeable people here. In
> > particular Lee Hart for his voltage clamper and
> pack
> > monitor designs. So simple that even a electronic
> > novice like myself can understand. :<)
> > Thanks again,
> > Jeff McCabe
> > http://www.austinev.org/evalbum/736
> >
> >
>
>
>
>
>
____________________________________________________________________________________
> Yahoo! oneSearch: Finally, mobile search
> that gives answers, not web links.
>
http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC
>
>
--- End Message ---
--- Begin Message ---
Man, if I could get A123 M1s for US$5 each, I would buy 2000 of them
tomorrow.
But, they weren't very welcoming of my enquiries, so I'll be going to
a Taiwanese company instead.
A little disappointing though..
On 09/07/2007, at 9:20 PM, Marcin Ciosek wrote:
A123 prices are indeed way below 10$, even below 5$ but they are
really hard
to get.
I was able to get far better contact with people from PHET and
their cells are
at the same level of quality (which was confirmed by HydroQuebec -
owner of
LiFePO4 patent) as A123.
Anyway, we can provide welded and wired blocks of any number of
cells in
parallel (machine made welding) as well as BMS customized for proper
construction. Right now I'm finishing test of 42P43S 18650 LiFP
cells on test
bench and right after the test are finished we will put it into our
car and
give it to testing company.
In my personal opinion - using big capacity cells or small ones in
parallel
gives similar results, but we will see after first 100 or 200 cycles.
Marcin
--- End Message ---
--- Begin Message ---
R is the total resistance in the circuit. Since everything is is
series (right?) R is the just the sum of the individual resistances...
If anything is in parallel, remember that R will be the reciprocal of
the sum of the reciprocals though.
Not sure i understand the heat shrink question... you can split heat
shrink because it relys on the hoop tension of a complete circle to
hold on. If it's split, it'll just peel itself off when you shrink
it. Can't you just unbolt the connection and slip in on?
Z
On 7/9/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
analogy then question.
if i have to get 100 people out of a room but there is only one door, the
"CURRENT" of people is limited by the door.
So, in my EV I am upgrading to 2/0 cable with clamp on connectors as
opposed to the 1/0 cable with lug end connectors.
It'll be like 2 doors instead of 1 (less resistance).
The question is, If I have one or two 1/0 cables or one lug end
connector., does that make the whole loop as if it were 1/0 or the I^2/R
equation means I only loose a little of voltage whereas with all 1/0
cabling I loose ALOT of VOLTAGE?
also, what do you do when you forget to put the heat shrink on a few of the
cables?
do you split the 2/0 heat shrink, and then put overtop of it the size heat
shrink that will slide over the clamp?
gracias,
Ben
--- End Message ---
--- Begin Message ---
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--- Begin Message ---
Ian,
I have access to A123 cells because of different project where their cells are
used. It's very hard to get from them anything more than agreed quantity and
you have to be backed up with very important company before they start
talking about business. In fact, they don't care about single orders, 2000
cells is a peanut for them. As all know - their whole production is sold out
to power tools.
That's why I'm more focused on PHET.
I'm doing some comparison tests between A123 and PHET and we will see.
For most of us long term and reliability is very important because we are
putting our own money for conversion and if we spent few thousands on BP we
would like to run on it for very long time.
For products like Tesla the initial performance is more important, they will
write some small print information in car manual that the range and
performance may decrease with the cycles and they are covered.
If you can afford 100k car you will buy new pack within 1 year just to keep
the performance.
That's my opinion.
Anyway, I'll keep you informed about results.
Marcin
--- End Message ---
--- Begin Message ---
Slowly, slowly, keep you love for your car.
Anyway, because I personally (or rather the company) need a decent replacement
for 50Ah single cells I've decided to build blocks of 21 parallel 1.2Ah cells
(so two blocks in parallel is the equivalent of 50Ah battery). If the tests
we are doing right now will succeed we will start to offer those blocks as a
products. Of course BMS will be an option. Some people may don't need such
sophisticated BMS which has CAN interface, programmable realtime analysis,
battery history storage and so on, so for them we can offer a BGS - Battery
Guarding System, that will give you a behavior similar to lead-acid with just
a simple protection circuit that will react on critical states.
So, that's the plan. Everything depends on how the idea of thousands
parallel/series cells will behave.
In my opinion the most important thing is cyclelife - that's the most unknown
variable for any solution. I can test cells with 10C constant current
discharge but it takes a lot of time to tell anything about durability.
Anyway,
at the moment I'll have anything ready to sell I'll let people on the list
know first.
Regards,
Marcin
--- End Message ---
--- Begin Message ---
Hi Everyone,
Please let me thank you guys in advance for any replies.
Firstly, I should mention my background. I'm a 2nd year student at
Carleton University in Ottawa studying chemistry and computer science.
I'm turning 19 soon and pretty much have no experience with cars,
electricity, or motors. I understand the concepts, but have no
hands-on experience. However, I learn quick and am definitely willing
to spend a large chunk of my free time doing this conversion. Most of
you probably think I'm crazy by now for even considering this, but I
wouldn't be attempting this conversion if I didn't have the help of my
dad. He's currently the tech department head at a high school in
Toronto and has access to all the classrooms and shops. We have access
to ProENG and 4 axis CNC milling machines and lathes. He holds a
B.Eng in mechanical and has the great advantage of access to free
(student) labor. He's also had considerable experience working in the
industry and can refer to his friend, the electrical engineer, for
help with electrical issues. Our agreement is that I do the research,
he advises on technical issues, and the students do the labor (I'll
help when I'm in town).
I'll describe my situation:
I'm going to come into possession of 2 Mercedes cars, hopefully, in
the near future. They are the 1987 260e and 300e models.
The 260e was purchased by my grandfather 2nd hand in 1988 and has a
near pristine body. There's only a bit of rust on the rear left door.
The engine was also brought to the dealership every year for tuneups,
but it's starting to show signs of wear now after 20 years. It has an
automatic transmission, unfortunately, and I think will become
available as a donor within 3 or 4 years. I'm quite sure it's been
driven less than 150 000km (!).
The 300e is my uncle's temporary vehicle and the engine is in very
poor condition, although the body is in fair condition. It spends more
time in the shop than out of it, and I think I can obtain it within
the year. It has a standard transmission, but it is also in very poor
condition. I can hear it constantly when sitting in it, and there is a
persistent smell of burnt plastic/oil. I think it may be necessary to
replace it, so that should be added into the cost (more on that
later).
I'm planning to convert the 300e, and then move onto the 260e when the
300e finally kicks the bucket. They both use identical chassis, so I'm
hoping it won't be too hard to switch over.
A few quick stats about both the cars:
curbside weight: 3100lbs
carrying capacity: unknown
Co-efficient of friction: ~0.22
Lots of trunk space, lots of engine space.
And my intended usage will be:
- daily commute, 40 km round trip mostly flat ground. Should allow
for up to 80km or 100km though, for those proverbial rainy days.
- 100-120km/h maximum velocity. Definitely does not need to be a
speed demon. Reliability and range are much more important to me.
- Highway use maximum 3 or 4 times a week, mostly local roads or
traffic jams, 60km/h.
- Canadian climate. -30C winters, 30C summers.
- Future expandability to use with fuel cell?
Budget: $10 000CDN = ~ 9500USD
So based on the information and criteria given, which set up should I choose?
- Battery:
I've been dreaming about the A123 batteries, but realistically, I can
only afford Lead Acid. I'm not sure whether I should choose AGM/Gel,
or regular flooded. What would be the normal cost for these batteries
for an application of my size? I know those cars are quite heavy. The
usual cars I see converted are almost 1000lbs lighter than the 260e.
the T105s look nice, but I have little experience in this area. I'm
not even sure if the 260e can support the weight of the batteries, (I
estimated 1000lbs) since I can't find any information on the carrying
capacity of the chassis.
- Motor/Controller:
I can't decide on DC or AC. I know that this usually ignites a
firestorm of email when this issue is raised, but I'm truly clueless,
so please help me out.
Please don't hesitate to comment if my reasoning seems flawed at any point.
I would ideally like to go with AC, because efficiency seems to be
higher with regenerative braking and the solutions seems to be more
professionally designed and reliable in the long run? However, the
BRUSA motor/controller looks like it costs 3 times my budget! Is it
possible to run an AC set up with my budget? Victor seemed to be able
to put together the Siemens set within my budget, but I'm not sure if
those prices are still available, and within Canada.
However, although DC seems to be a less "professionally designed"
solution, it also does not look bad. It may be the only thing within
my budget. The problem is that I'd prefer a programmable motor
controller, since I'm going to be fully integrating this car into a
car PC running Linux. Most of the DC motor controllers make me nervous
though, partly based on the size, and partly based on the overall look
of the motor controller and lack of data logging features. There seems
to be an overall lack of engineering data available for the DC motor
segment, so that also adds to my worries. I'd prefer to have as many
sensor readings as possible coming from the car, just to make sure
everything is running within normal ranges. I'm not sure if there's
any DC motor controller out there within my budget that meets those
needs. Are my worries unwarranted?
Also, what range of power would I be looking for? I suspect that I
would need a 70+ kw nominal motor since the car is so heavy, but
that's really just a rough estimate based on a ratio of the CRX ICE
and victor's EV horsepowers and the 260e's ICE horsepower.
So basically those are the 2 biggest questions regarding my set up.
I'm not afraid of any mind boggling reading either, so if you guys
have good resources for a relative "newbie" to the field, pile it on.
I've been to most of the EV sites readily available through Google,
and probably all of the major motor manufacturer sites and wiki pages,
but I feel that I should be reading much more about it.
Oh also, included in this budget needs to be a car PC. No worries, it
shouldn't cost more than $500. I'm going to "start" this baby up with
a USB key =D.
Thanks for all your help guys.
Matt
--- End Message ---
--- Begin Message ---
Matt, here is just an idea:
1. Choose a 240D instead to get the 4 cylinder diesel model Mercedes.
2. Change to manual transmission if necessary
3. Install a 20 to 40kw motor in the driveline. Preferred type would be a
brushless with permag field. (fixed driveline ratio and need for high
torque)
4. Install a battery pack with about a 20 mile or slightly limited range.
This cuts down the cost if you are going to try to buy lithiums.
You now have a plug in parallel hybrid that can be run on electricity alone
or a combination of electricity and diesel or diesel alone. You can spend
years calculating the best blending of the two modes for minimum fuel usage.
Of course, you want regenerative braking to boost efficiency in both modes.
I also dream about doing this with a FWD diesel such as the VW Rabbit
Diesel, by leaving the diesel front wheel drive intact, and adding electric
drive to the rear axle. Again, you end up with a parallel plug in hybrid
that has low cost electric mode for daily short trips, and unlimited range
for long trips and hopefully diesel mileage in excess of the 50MPG of the
car in original stock condition. Good luck and would like feedback on your
progress. George
On Mon, 9 Jul 2007 11:33:24 -0400, Matthew Chan wrote
> Hi Everyone,
>
> Please let me thank you guys in advance for any replies.
>
> Firstly, I should mention my background. I'm a 2nd year student at
> Carleton University in Ottawa studying chemistry and computer
> science. I'm turning 19 soon and pretty much have no experience with
> cars, electricity, or motors. I understand the concepts, but have no
> hands-on experience. However, I learn quick and am definitely
> willing to spend a large chunk of my free time doing this
> conversion. Most of you probably think I'm crazy by now for even
> considering this, but I wouldn't be attempting this conversion if I
> didn't have the help of my dad. He's currently the tech department
> head at a high school in Toronto and has access to all the
> classrooms and shops. We have access to ProENG and 4 axis CNC
> milling machines and lathes. He holds a
> B.Eng in mechanical and has the great advantage of access to free
> (student) labor. He's also had considerable experience working in
> the industry and can refer to his friend, the electrical engineer,
> for help with electrical issues. Our agreement is that I do the
> research, he advises on technical issues, and the students do the
> labor (I'll help when I'm in town).
>
> I'll describe my situation:
>
> I'm going to come into possession of 2 Mercedes cars, hopefully, in
> the near future. They are the 1987 260e and 300e models.
>
> The 260e was purchased by my grandfather 2nd hand in 1988 and has a
> near pristine body. There's only a bit of rust on the rear left door.
> The engine was also brought to the dealership every year for tuneups,
> but it's starting to show signs of wear now after 20 years. It has an
> automatic transmission, unfortunately, and I think will become
> available as a donor within 3 or 4 years. I'm quite sure it's been
> driven less than 150 000km (!).
>
> The 300e is my uncle's temporary vehicle and the engine is in very
> poor condition, although the body is in fair condition. It spends
> more time in the shop than out of it, and I think I can obtain it within
> the year. It has a standard transmission, but it is also in very poor
> condition. I can hear it constantly when sitting in it, and there is
> a persistent smell of burnt plastic/oil. I think it may be necessary
> to replace it, so that should be added into the cost (more on that
> later).
>
> I'm planning to convert the 300e, and then move onto the 260e when
> the 300e finally kicks the bucket. They both use identical chassis,
> so I'm hoping it won't be too hard to switch over.
>
> A few quick stats about both the cars:
> curbside weight: 3100lbs
> carrying capacity: unknown
> Co-efficient of friction: ~0.22
> Lots of trunk space, lots of engine space.
>
> And my intended usage will be:
> - daily commute, 40 km round trip mostly flat ground. Should allow
> for up to 80km or 100km though, for those proverbial rainy days.
> - 100-120km/h maximum velocity. Definitely does not need to be a
> speed demon. Reliability and range are much more important to me.
> - Highway use maximum 3 or 4 times a week, mostly local roads or
> traffic jams, 60km/h.
> - Canadian climate. -30C winters, 30C summers.
> - Future expandability to use with fuel cell?
>
> Budget: $10 000CDN = ~ 9500USD
>
> So based on the information and criteria given, which set up should
> I choose?
>
> - Battery:
> I've been dreaming about the A123 batteries, but realistically, I can
> only afford Lead Acid. I'm not sure whether I should choose AGM/Gel,
> or regular flooded. What would be the normal cost for these batteries
> for an application of my size? I know those cars are quite heavy. The
> usual cars I see converted are almost 1000lbs lighter than the 260e.
> the T105s look nice, but I have little experience in this area. I'm
> not even sure if the 260e can support the weight of the batteries, (I
> estimated 1000lbs) since I can't find any information on the carrying
> capacity of the chassis.
>
> - Motor/Controller:
> I can't decide on DC or AC. I know that this usually ignites a
> firestorm of email when this issue is raised, but I'm truly clueless,
> so please help me out.
> Please don't hesitate to comment if my reasoning seems flawed at any
> point.
>
> I would ideally like to go with AC, because efficiency seems to be
> higher with regenerative braking and the solutions seems to be more
> professionally designed and reliable in the long run? However, the
> BRUSA motor/controller looks like it costs 3 times my budget! Is it
> possible to run an AC set up with my budget? Victor seemed to be able
> to put together the Siemens set within my budget, but I'm not sure if
> those prices are still available, and within Canada.
>
> However, although DC seems to be a less "professionally designed"
> solution, it also does not look bad. It may be the only thing within
> my budget. The problem is that I'd prefer a programmable motor
> controller, since I'm going to be fully integrating this car into a
> car PC running Linux. Most of the DC motor controllers make me
> nervous though, partly based on the size, and partly based on the
> overall look of the motor controller and lack of data logging
> features. There seems to be an overall lack of engineering data
> available for the DC motor segment, so that also adds to my worries.
> I'd prefer to have as many sensor readings as possible coming from
> the car, just to make sure everything is running within normal
> ranges. I'm not sure if there's any DC motor controller out there
> within my budget that meets those needs. Are my worries unwarranted?
>
> Also, what range of power would I be looking for? I suspect that I
> would need a 70+ kw nominal motor since the car is so heavy, but
> that's really just a rough estimate based on a ratio of the CRX ICE
> and victor's EV horsepowers and the 260e's ICE horsepower.
>
> So basically those are the 2 biggest questions regarding my set up.
> I'm not afraid of any mind boggling reading either, so if you guys
> have good resources for a relative "newbie" to the field, pile it on.
> I've been to most of the EV sites readily available through Google,
> and probably all of the major motor manufacturer sites and wiki
> pages, but I feel that I should be reading much more about it.
>
> Oh also, included in this budget needs to be a car PC. No worries, it
> shouldn't cost more than $500. I'm going to "start" this baby up with
> a USB key =D.
>
> Thanks for all your help guys.
>
> Matt
--- End Message ---
