EV Digest 3827
Topics covered in this issue include:
1) Re: Circuit Breakers, Fuses and switches
by Victor Tikhonov <[EMAIL PROTECTED]>
2) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Contactor voltage rating -- What's the deal?
by Lee Hart <[EMAIL PROTECTED]>
4) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by Lee Hart <[EMAIL PROTECTED]>
5) Re: Circuit Breakers, Fuses and switches
by "Roland Wiench" <[EMAIL PROTECTED]>
6) Re: Looking for compact over-run clutch for regen....
by mark ward <[EMAIL PROTECTED]>
7) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by Victor Tikhonov <[EMAIL PROTECTED]>
8) RE: Ultracap cell balancing - burning batteries
by "Mark Fowler" <[EMAIL PROTECTED]>
9) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by Victor Tikhonov <[EMAIL PROTECTED]>
10) Like engineers discussing EVs:
by [EMAIL PROTECTED]
11) Re: Looking for compact over-run clutch for regen....
by Victor Tikhonov <[EMAIL PROTECTED]>
12) Re: Deafscooter's 1 St place on Route 66 Rally 9/25
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
13) Re: The first EV sports car
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
14) DO NOT BURN ULTRACAPs !!!!!!!!
by mark ward <[EMAIL PROTECTED]>
15) Re: Ultracap cell balancing - burning batteries
by Victor Tikhonov <[EMAIL PROTECTED]>
16) Re: Looking for compact over-run clutch for regen....Maxwell?
by mark ward <[EMAIL PROTECTED]>
17) Re: DO NOT BURN ULTRACAPs !!!!!!!!
by Victor Tikhonov <[EMAIL PROTECTED]>
18) RE: Like engineers discussing EVs:
by Steven Tweed <[EMAIL PROTECTED]>
19) Re: DO NOT BURN ULTRACAPs !!!!!!!!
by Seth Allen <[EMAIL PROTECTED]>
20) Re: ProEV's Imp on track! (part 2) (long)
by Sam Uzi <[EMAIL PROTECTED]>
21) RE: Deafscooter's 1 St place on Route 66 Rally 9/25
by "Roger Stockton" <[EMAIL PROTECTED]>
22) Re: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
by "M.G." <[EMAIL PROTECTED]>
23) Re: EV Generators
by Christopher Robison <[EMAIL PROTECTED]>
--- Begin Message ---
One source - http://www.bussman.com/products/hispeed/Group1.asp
Victor
Don Cameron wrote:
I am looking for a 400V, 300A circuit breaker for the pack for my AC
system.
As well, I am looking for a fuse and switch to handle 40A 400v switch for
testing purposes.
I have looked at the EV supply stores, but they are limited to lower
voltages.
Any suggestions on where I look to find such parts?
thanks
Don
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
> Resistors work just fine (only a a bit wasteful) because
> equalization happens over many stand by hours, not
> during driving.
>
> During drive and heavy regens the voltages are not equal
> but it is not relevant - faster discharging caps also
> charge faster coming to the same voltage anyway.
Victor, at Honeywell we tried using five supercapacitors on a project as
a replacement for a 12v backup battery to drive a small motor. They
didn't work out for a number of reasons; one of them was equalization
problems.
You're right; simple resistors will equalize fine if you have lots of
time available for charging and discharging. But, more aggressive
equalization is needed if you have to deal with fast charging and
discharging.
The problem is caused because each cell has a different capacitance.
Suppose there is a 20% difference between the cells. You start with them
all fully charged, and apply a high discharge current. The
lowest-capacitance cell will go dead when the rest still have 20%. Then
it goes negative (at high current). This destroys the capacitor.
The reverse situation happens while charging at high rates. The
lowest-capacitance cell reaches its max voltage limit 20% before the
rest, and fails.
Since these were small 10 farad 2.5v cells, we put a 2.4v 1w zener
across each one. On charge, they clamped overvoltage; on discharge, they
acted as a diode to limit reverse voltage to -0.6v. Our max
charge/discharge currents were not high enough to endanger these zeners.
On larger capacitors, I think you would be led into the same situation
we get with batteries. The greater the mismatch between cells, and the
higher the total pack voltage, and the larger the charge/discharge
current, the worse the balancing system requirements will be.
> And, again, why bother? You don't equalize good batteries while
> driving, do you? (boosting a crippled weak one one is different
> issue).
Yes, in fact, we sometimes do. The PowerCheq, Zivan Smoother, Badicheq,
and my own Battery Balancer all balance while driving. Intelligently
done, it maximizes the performance and extends the life of the
batteries.
I could see such a balancing system having merit with a long string of
ultracapacitors, too. The system could figure out the actual capacitance
of each cell from its charge/discharge voltage vs. current, and then add
or remove charge from each so as to prevent any cell from going over- or
under-voltage. In effect, this lets you use smaller (cheaper) capacitors
to get the same energy storage capacity. It also lets you detect weak or
failing capacitors before they do something drastic.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Eric Poulsen wrote:
> So, could you use a 1000A 60VDC contactor with a 120V EV system,
> assuming < 500A battery current?
Yes, to a point. However, cutting the current in half does not double
the safe working voltage. Halving the current gives you more like 20%
more voltage capability. So, a 1000a 60v contactor could be used at 500a
72v.
A much better way to increase the voltage rating is to increase the gap
between contacts. For example, that huge 1000a 60v contactor that was
just posted actually has 3 contact pairs in parallel. If you sawed the
copper plates lengthwise to separate them into 3 independent contact
pairs, and wired these pairs in series, it becomes a 333a 180vdc
contactor.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
> Disconnected, they lose 1V every 3 min...
> Trouble is I have to disconnect the caps because they make
> it impossible to deploy variable charging current algorithm
> required by TS cells - they smooth out all the pulses
> in regulation.
>
> I will probably end up maintaining the stack voltage straight
> from the mains, simply rectified output and 100 mA capable
> secondary will be just fine.
Hmm... Since the capacitors will draw a "fixed" current due to the
resistors... Get yourself N identical tiny little 60 Hz transformers.
The voltage and current ratings mean nothing; you won't be able to find
one so small it can't deliver 3v at 10ma.
Wire a rectifier and 39 ohm load resistor to each secondary. Connect one
to each capacitor. Don't make any connection to the transformer primary.
Here's the trick. String a single long, heavy wire thru each transformer
core. It loops thru each core, like beads on a string. Most cheap
transformers have room to poke a wire thru; if yours don't, then cut off
the primary to make room. What you have is a 1-turn primary for every
transformer. All these primaries are hooked in series, so their primary
currents must be identical. Therefore, their *secondary* currents must
be identical. The fixed load resistors mean that the voltage across
these resistors must be identical. Therefore, all capacitors will be at
the same voltage!
Drive the primary wire with a single, larger transformer's secondary.
The exact current you have to run in this winding will depend on the
turns ratio. The easiest way is probably to include one more small
transformer in the loop, with rectifiers, 39 ohm resistor, and a much
smaller capacitor; measure the voltage across its resistor to estimate
the steady-state voltage across all the rest.
Use LEDs as your rectifier diodes, and you'll be able to see which ones
are charging the most. :-)
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Try Electrical supply houses. They have General Electric, Westinghouse, Sq
D, CutlerHammer and etc.
For AC you can used a 480 VAC rated Circuit Breaker. You have a choose of
magnetic interrupting ratings.
These are so expensive, ranging from $200.00 to more than $10,000.00. I
choose to used Bussman Limitron 400 amp with a 200,000 A interrupting
rating. Or you can used a cheaper semiconductor fuse which are about $60.00
Each.
For a switch, used a fusible 480 VAC heavy duty knife switch in any ampere
made by GE, etc. These are standards we used in construction.
Roland
----- Original Message -----
From: "Don Cameron" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, September 29, 2004 3:18 PM
Subject: Circuit Breakers, Fuses and switches
> I am looking for a 400V, 300A circuit breaker for the pack for my AC
> system.
>
> As well, I am looking for a fuse and switch to handle 40A 400v switch for
> testing purposes.
>
> I have looked at the EV supply stores, but they are limited to lower
> voltages.
>
> Any suggestions on where I look to find such parts?
>
> thanks
> Don
>
>
>
>
>
--- End Message ---
--- Begin Message ---
I have been watching this thread and it looks like
-Rich- you are the man that will be able to answer a question I have regarding DC PM
motors. You have indicated that DC Permanent Magnet motors will always present losses
even if the armature is left open. Up to now I could not get the answer as to if you
have an open unconnected coil of wire spinning in a magnet induced magnetic field why
this would be so. You seem to indicate it is because of eddy currents.
Assuming this is true-my question is two fold-first-do the losses increase linearly
with motor rotation (with a motor that is rotated by an external force and with the
armature left coil left open)?
Second- as compared to the braking forces generated by a PM motor during regenerative
braking (something connected across the armature)-at the same RPM and as a
percentage-what is the braking force generated by a PM motor that has its armature
left unconnected.
My project involves using two PERM Motor PMG 132 DC PM motors connected directly the
rear axles of my 2003 Honda Element. They will be used to recharge a bank of
ultracaps-which will be used to power an electric supercharger and as well, when the
electric supercharger is not in use, to assist the ICE-but that is another topic.
Any one else with answers please chime in.
By the way-I work for Maxwell-feel free to query me on ultracaps. So far the ultracap
thread has been pretty accurate. Maxwell has a pretty nice interactive calculator on
their website that you can use to figure out how many ultracaps you would need to
proved a given current between a given voltage window over a given time.
Thanks
---------------------------------
Do you Yahoo!?
Read only the mail you want - Yahoo! Mail SpamGuard.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
...
The problem is caused because each cell has a different capacitance.
Suppose there is a 20% difference between the cells. You start with them
all fully charged, and apply a high discharge current. The
lowest-capacitance cell will go dead when the rest still have 20%. Then
it goes negative (at high current). This destroys the capacitor.
The reverse situation happens while charging at high rates. The
lowest-capacitance cell reaches its max voltage limit 20% before the
rest, and fails.
Lee, you are missing the fact that the caps will never be discharged
deeper than 50%-60% DOD, they are in parallel with LiIons.
If they discharged to 0V, this means LiIon pack is at zero volt
which is [normally] never the case. And, they are never at 0% DOD.
Perhaps DOD is not good term here because there is no definition
of "full". Whatever voltage I choose to start out with - is my
"full" I can easily exceed if leave some the room in advance.
If I start off with balanced pack (overnight equalization and
highest voltage on the pack), smaller value capacitors will
discharge deeper but still to no less than half of the voltage.
So when coming back, the process reverses and if they all were
to reach the same total voltage, they will all be at the same
balanced state as before first discharge - *provided* that
imbalances are solely due to capacitance differences, not
leakages. Different leakages will cause unrecoverable imbalance
throughout the day, but the leakage current is milliamps, so
due to that overall imbalance in one day is totally unmeasurable.
I do have few capacitors with different steady voltages on each.
The difference is minor (50 mV or so) but fixed. After I drive
and absolute voltage on the pack is lower, when I charge the caps
in series these two come to the same 50 mV difference without
any effort. If I wouldn't mind too tedious task, perhaps I could
measure individual voltages and trim individual resistors such that
the voltages at equilibrium are identical. I don't feel this is
necessary since in reality the caps always operate only between
about 50% to 90% of their max voltage. So if some swing between
52% and 92% due to initial lower leak and so higher voltage, so what?
The same about lowest ones - 48% to 88% is fine with me as long
as it does not drift apart day after day, and it doesn't.
The price for this robustness is that I paid for a capacitor
but take advantage only of third to a half of it. This is
the compromise I knew about before I started, and all things
considered this was the best overall balance (for me) between
cost, weight and complexity.
Looks like it is not enough charges-discharges in a normal day
driving to cause alarmingly large SOC differences - at least
it appears that way so far in my setup.
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Hi Victor,
Do you have any more info about the results of this TS Li-Ion test?
Mark
-----Original Message-----
From: Victor Tikhonov [mailto:[EMAIL PROTECTED]
Sent: Thursday, 30 September 2004 7:20 AM
To: [EMAIL PROTECTED]
Subject: Re: Ultracap cell balancing
We (Jukka and I) already disassembled and burned a
TS LiIon cell for a test, so we know what parts of it are
combustible and how they sustain fire. Once we have a sample of
a cap, we'll do similar test.
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
Hmm... Since the capacitors will draw a "fixed" current due to the
resistors... Get yourself N identical tiny little 60 Hz transformers.
The voltage and current ratings mean nothing; you won't be able to find
one so small it can't deliver 3v at 10ma.
Unless I misunderstand you, capacitors do not draw fixed
current. The current depends on individual "R_int" and resistor
just being a poor man's fixed (to reasonable degree) voltage
source. Each cap shunts its resistor with own R_int which is
about 10 times more than 39 Ohm (worst case), so the voltages
on the 1% resistors ladder are no longer quite the same, but
acceptably close, within 10%. The current through a cap can
vary wildly, can be several orders of magnitude different
(0mA for "ideal" caps to 6 mA for worst ones, but as long as
it represents only 10% of what flows through resistors (which is
60 mA at full charge), I don't care - the error cannot exceed 10%.
Am I missing something?
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
http://media.ebaumsworld.com/retro.wmv
--- End Message ---
--- Begin Message ---
mark ward wrote:
By the way-I work for Maxwell-feel free to query me on ultracaps.
So far the ultracap thread has been pretty accurate. Maxwell has
a pretty nice interactive calculator on their website that you can
use to figure out how many ultracaps you would need to proved a given
current between a given voltage window over a given time.
Thanks
Mark,
You, then, is the best person to qualify for answers about reliability
of Max ultracaps. Please tell us (leaving marketing ads aside :-)
how do they fail. Does Maxwell has any data on actual cycle life
measured or reported by a customer (not calculated or extrapolated)?
What is MTBF spec? Is it OK to keep a cap at near max voltage
(2.3V) for its life doing only shallow discharges and charging back?
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
He was competing against gas scooters. He won overall. Last meet he came
in second overall by a few yards. Nuf said. Lawrence Rhodes.......
----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, September 29, 2004 11:47 AM
Subject: RE: Deafscooter's 1 St place on Route 66 Rally 9/25
> Lawrence Rhodes [mailto:[EMAIL PROTECTED] wrote:
>
> > Scooters go 18mph. These guys all modify them.
>
> ~All~ stock gas and electric scooters go 18MPH? ;^>
>
> Modified or not, I just would like to know what sort of performance the
> scooters he "raced" against was. Without this context, reports of his
> scooter's performance are much less meaningful.
>
> > He is racing
> > against non stock scooters with a non stock electric scooter.
>
> This appears to have been a "rally" not a "race". Unfortunately, in
> addition to not finding any record of any participant's performance on
> the AMMRA site I also didn't find any mention of what (if any)
> competition actually took place at this event.
>
> > If you had attended one of the scooter meets and seen one or
> > more of Craigs creations you would know better.
>
> Agreed, however, like many on this list, I don't happen to live in
> California and therefore it is unfortunately quite likely that I will
> never meet Craig or see one of his creations in person.
>
> Extraordinary claims are made for Craig's creations and extraordinary
> claims require extraordinary proof.
>
> > In the last meet he came in second
> > by a few yards with a smaller pack. I guess he figured over
> > kill was better than second place.
>
> Since he appears to have been alone in his class this time, it was
> impossible for him to come in second. ;^>
>
> I'm not faulting him for using a larger pack, etc., I am just trying to
> get a feel for how his performance compared to that of the other
> participants and to understand exactly who he was competing against.
> First in a field of one is meaningless.
>
> He had to swap packs to complete the rally; were the gassers allowed to
> refuel? Could they have completed the rally at higher speed if they
> were allowed to refuel (i.e. did they have to drive more conservatively
> than Craig because of having to complete the rally on a single tank of
> fuel)?
>
> If the answer to my question is that nobody here knows what the
> performance of the other participants was for comparison, that's OK
> (unfortunate, but OK); just say so.
>
> Thanks,
>
> Roger.
>
--- End Message ---
--- Begin Message ---
Sounds like you guys want to race for pink. I really like the speed stories
and all that but for us real world EV users it's all about just getting
there. I very rarely go faster that 75. So 0 to 60 means more to me than
100 mph in the quarter. Range also means more to me. I just hope all you
guys can steal from each other, give us good ideas & make some good
affordable stuff for us pluggers. A nice fast charger about the size of a
note book would be nice. Something for the motorcycle or packs between 100
& 400 pounds. Hint hint ....Lawrence Rhodes....
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, September 29, 2004 1:10 PM
Subject: Re: The first EV sports car
>
> ----- Original Message -----
> From: "John Wayland" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Wednesday, September 29, 2004 8:47 AM
> Subject: Re: The first EV sports car
>
>
> > Hello to All,
> >
> > The title of this post irritates me. The first EV sports car has already
> come and gone,
> > long before this new entry was even conceived...it was called the EV1.
The
> EV1 was here 10
> > years ahead of the Fetish, and was a sleek two seater electric sports
car
> within financial
> > grasp of many. Road & Track tested it and got 0-60 in 7.6 seconds, and
> with NiMH
> > batteries, I got a real world 145 miles per charge range when renting
one
> while traveling
> > in California.
> >
> > John Westlund wrote:
> >
> > > The TZero is high 11s/ low 12s
> >
> > John, where are you getting these stats? Take it from me, getting a
street
> legal electric
> > car into the 12's is no small task. Getting a production based, all
steel
> car with real
> > windows, real bumpers, real doors, and a real roof, to run in the 12's
let
> alone 11's, is
> > very hard to do.
> >
> > Many of us work very hard to design, build, and at sanctioned NHRA 1/4
> mile drag
> > strips and under NEDRA regulations race our electric drag cars. We come
> away with bonafide time
> > slips that show everything and support our performance claims. White
> Zombie's world record
> > 12.991 @ 101.18 mph time slip is posted at the Zombie's page in the EV
> Photo Album for all
> > to see and inspect.
> >
> > We've invited AC Propulsion to come to NEDRA drag race EVents, but
they've
> never attended.
> > I have no doubt that the lithium powered tZero could crack the high
12's,
> as it ran a 13.2
> > second 1/4 mile ET when it was heavier and powered by 28 lead acid
> Optimas. High 11s/ low
> > 12s? Show me the time slips!
> >
> > I've seen the tZero videos, most recently, the one with funky earth
muffin
> music playing
> > (no drum track, no bass content, no 'impact'...hardly the kind to
support
> aggressive,
> > tire-shredding 'real' drag racing) where they race the tZero against a
> Porsche 911 in the
> > rain on some airport tarmac. There were no timing lights, no speed
traps,
> and it was not
> > even close to being NHRA approved. Instead, they have some dude with an
> umbrella to act as a
> > Christmas tree.
> >
> > The other 'drag races' AC Propulsion uses in their PR, shows their car
> > racing against a Corvette, a Porsche 911, and Ferrari F355...all in the
> 1/8th mile, not
> > the more stringent 1/4 mile, where real drag cars go to see what they
can
> do. There's a
> > reason for this, of course. AC Propulsion knows that in the full 1/4
mile
> drag,
> > these cars would blow past the tZero, who's performance is capped off
with
> a self imposed,
> > rev limited restricted top speed. Sure, they could change gear ratios to
> get the top speed
> > up, but doing that would then slow down it's sensational 0-60 time, and,
> it would still lose
> > to these same cars in the 1/4 mile drag. The tZero would get its fake
> doors absolutley blown
> > off by all three of these cars.
> >
> > AC Propulsion's 'drag race' claims (1/8th mile instead of tougher 1/4
> mile) are
> > reminiscent of Solectria's old tricks, when trying to mask their s-l-o-w
> EV's 0-60 times
> > they instead bragged about 0-50 in 10 seconds. They only ceased that
> nonsense when I
> > posted a challenge to their claims and exposed the fact that a car that
> does 0-50 in 10
> > seconds, takes an agonizing 17 seconds or so to crawl up to 60 mph. I'm
> certainly not
> > saying tZero isn't quick and fast, but quoting race stats that claim the
> tZero 'out-drag
> > races' expensive sports cars minus any 60 ft. times, minus any track
> registered 1/8th mile
> > times and speeds, and most important...minus any 1/4 mile ET and speed,
is
> a bit
> > misleading.
> >
> > > That TZero is an exceptional machine.
> >
> > Yes, in some ways it is, but in other ways...hardly. It's absolutely
> terrific that AC
> > Propulsion has forged ahead with power train and battery pack
innovations,
> especially the
> > recent lap top battery pack and phenomenal distance per charge
> achievements. The car has a
> > killer 0-60, and it has stunning performance in most areas. However, the
> hop-over fake
> > doors, the home-made build quality, and toy-like body structure (it's a
> kit car) are BIG
> > negatives.
> >
> > I'd like to see a real car with their technology poured into it. A small
> > production car made like other cars on the road, a car that passes all
> standards other
> > cars must pass, a car with functioning doors and all the other expected
> features...then
> > tout what 'this' car can do. For me, this would be far more impressive
> > than what the current 'car' does. Imagine how the general public would
> respond when seeing
> > a comparison of say a Toyota Corolla XRS, a spunky boy racer 170 hp
sedan
> with 0-60 in 7.1
> > seconds and a 1/4 mile ET of 15.8, to the 230 hp electric Corolla EV
with
> 0-60 in the low
> > 5 second range, a 1/4 mile ET in the mid 13's, and a
> never-have-to-go-to-the-gas-station
> > range of 200-230 miles! Do you have any idea how many eyebrows this
would
> raise?
> >
> > See Ya....John Wayland
> >
>
> I see John's points here.
> The ACP guys have staid off the drag strip.... Where the BS meets the
> Road.
> While I think that they could put up a fantastic showing... I also
think
> they don't want us to see the Weakness in thier design. It's really easy
to
> make somthing fast, but it's harder to make it both fast and quick. The
real
> question is Why they havn't just taken the Fast company Car to the nearest
> strip and bagged some Sub 12 to put into thier Add copy.
> With the hype this Car has the the respect that even us NEDRA racers have
> for it... They really need to come and play with the Fast street cars that
> we have.
>
> And yes I agree that the EV1 was a Electric Vette, come decades early.
Under
> Stemple it might be on the roads now, in numbers that could make a effect
on
> the PetroCarbon that we are Spewing in record numbers of tons.
> The Tzero is a Kit car compared to the Ev1. To compare them and thier
> stats is a insult the the hard hitting guys that made the EV1 happen. We
of
> course would love to see the Tzero in larger cheaper volumes with a
slightly
> less mindboggling BMS system.
>
> The Tzero is a Boy racer kit car. Nice but it's not production level.
Given
> a few dozzen orders...... that of course could change.
>
> What I don't understand is Why Allan and company doesn't show up with
about
> 500Kw and wax our NEDRA Butts back into the stone age of Brushed motors.
He
> could and he should.
> Hint Allan old Boy.... make it rear wheel drive, and don't spare the
> silicon, Bring Amps....and lots of them...per phase, of course.
>
>
>
>
>
--- End Message ---
--- Begin Message ---
I repeat DO NOT play around with burning ULTRACAPS. The acetonitrile electrolyte
IS!combustible in oxygen an under the right conditions can release a type of CYANIDE
gas. The caps are designed to handle normal use-as batteries are-but if you are
foolish to misuse them-for an expriment or other wise-well I guess thats why they call
it survival of the smartest.
---------------------------------
Do you Yahoo!?
New and Improved Yahoo! Mail - Send 10MB messages!
--- End Message ---
--- Begin Message ---
Mark Fowler wrote:
Hi Victor,
Do you have any more info about the results of this TS Li-Ion test?
Mark
-----Original Message-----
From: Victor Tikhonov [mailto:[EMAIL PROTECTED]
Sent: Thursday, 30 September 2004 7:20 AM
To: [EMAIL PROTECTED]
Subject: Re: Ultracap cell balancing
We (Jukka and I) already disassembled and burned a
TS LiIon cell for a test, so we know what parts of it are
combustible and how they sustain fire. Once we have a sample of
a cap, we'll do similar test.
I lost all the images of this test (oversized memory card in my
camera got all the files corrupted). It is easy to repeat though,
I just don't have a dead cell I can commit to it.
Basically, nothing inside sustain open fire. IT sort of burns
as long as you keep blazing it with a torch but if you remove
the flame, it self extinguishes. The only material sustaining
fire is plastic shell - it took some effort to ignite it, but
when the fire started, it half burns/half melts by itself.
Similar to polyethylene bottle.
Insides consist of a foil thin electrodes arranges as a
book pages with paper-like separator soaked with electrolyte.
Foils of different material alternate in the stack and on one
edge all positive foils are bolted together with a screw and
metal block being one of the top terminals, and similarly all
negative foils are arranged. We separated the paper (or whatever
fabric it is) with electrolyte and tried to burn it - it does not
burn.
So the main concern seem to be the shell. Electrolyte will
start decompose at about 5.5V and this may or may not be
run-away condition, I don't know. The temp will rise, and of
course if the battery still being charged, the energy keeps
turning into the heat eventually igniting plastic shell. And,
if you have rows of cells, it's a lot of plastic to burn and
most likely ALL the cells in the same box will catch the fire.
It is hard to attach a number to how difficult it is to
put out fire with water. Fundamentally you must lower the
plastic temperature below fire-sustaining value. Or course,
you must disconnect charger. If you severely overcharge but
manage to keep the battery cool, internal pressure will rise
and the shell eventually will crack, but will not ignite.
This is all I can tell. Download TS safety report from my web
site, they have done burning and deliberate overcharging tests.
According to TS it was very difficult to ignite a cell.
One can manage if is totally negligent (tun the charger for
hours after battery is full and does nothing about voltage
exceeding max by a lot, like 1V or so).
--
Victor
'91 ACRX - something different
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Victor asked about Maxwell Ultracaps. I work for them so keep that in mind. My
comments are to the old square 2500 PC2500 2.5 caps. These caps "will fail" if you
overvoltage them (above 2.5 volts). However-otherwise they are very reliable. You
can discharge to 0 volts-no problem. We have an ongoing life cycle test that is not
marketing hype that does support a life of over 500,000 cycles tested 0 to 2.5 volts
at 100 amps up and down up and down ad infinitum. The test is done in a fast duty cyle
environement and for this reason we expect these puppies to last for life of
application. Invariably they some do fail for the normal reasons-typically from a bad
seal. Gota go home-more tommorrow if you wish.
---------------------------------
Do you Yahoo!?
Yahoo! Mail - You care about security. So do we.
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mark ward wrote:
I repeat DO NOT play around with burning ULTRACAPS. The acetonitrile
electrolyte IS!combustible in oxygen an under the right conditions can
release a type of CYANIDE gas. The caps are designed to handle normal
use-as batteries are-but if you are foolish to misuse them-for an expriment
or other wise-well I guess thats why they call it survival of the smartest.
OK, OK, Mark, point taken. Just say it is a bad idea because so and so.
Please tell about normal fail mode - what happens if you overcharge one
- does it burst? Does it just die loosing capacity? Will electrolyte
decompose?
--
Victor
'91 ACRX - something different
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That is too much, I almost fell out of my chair!
Thanks!
-----Original Message-----
From: [EMAIL PROTECTED]
To: EV Discussion List
Sent: 9/29/2004 4:11 PM
Subject: Like engineers discussing EVs:
http://media.ebaumsworld.com/retro.wmv
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If you cpacitively couple the cans to an enclosure you can get a arc
with burns thru the can and starts the electrolyte on fire. You
capacitively couple them when you put them in a box that is conductive.
This has happened.
Seth
On Sep 29, 2004, at 8:01 PM, Victor Tikhonov wrote:
mark ward wrote:
I repeat DO NOT play around with burning ULTRACAPS. The acetonitrile
electrolyte IS!combustible in oxygen an under the right conditions
can release a type of CYANIDE gas. The caps are designed to handle
normal use-as batteries are-but if you are foolish to misuse them-for
an expriment
or other wise-well I guess thats why they call it survival of the
smartest.
OK, OK, Mark, point taken. Just say it is a bad idea because so and so.
Please tell about normal fail mode - what happens if you overcharge
one - does it burst? Does it just die loosing capacity? Will
electrolyte
decompose?
--
Victor
'91 ACRX - something different
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> This is a write up of our adventures back in July. I have been a little slow
> posting but with our next race (at Homestead-Miami Speedway) coming up this
> weekend, I figured I better get it done.
[...]
wow!! an exciting read! ...is it ok if I spamm this to a private mailing list
that I spew EV related stuff to?
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Lawrence Rhodes [mailto:[EMAIL PROTECTED] wrote:
> He was competing against gas scooters. He won overall.
Really? Can you point me to something that corroborates this?
According to the AMMRA site, Craig was the top *electric* finisher (out
of a field of 1), but there is no mention of him winning overall:
"Craig Uyeda was the top electric finisher with his awesome personal
electric creation that was clocked at 57mph! Mike Yartzoff of Hard Parts
USA was the top gas scooter finisher and John Kim was the top micro bike
finisher."
I could be mistaken, but it seems that if the participants are divided
into electric scooters, gas scooters, and micro bikes, then Craig was
competing only against the other electric scooters (of which there were
none). If he was competing against the other classes, then why were the
participants divided into classes to start with and why is the
performance of the micro bikes not being stated (if he won overall, then
he must have bettered their performance also)?
Cheers,
Roger.
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This voltage clamper. Would it act like a zener diode?If so where could
I find an example of such a circuit?
Mike G.
Emil Naepflein wrote:
On Tue, 28 Sep 2004 13:35:08 -0700, Victor Tikhonov <[EMAIL PROTECTED]>
wrote:
What I meant was you don't need the same equalization complexity
as for a battery (shunt regulators, or like). Simple resistor
network will do.
This kind of passive equalization is only feasable if you don't have
high current chargin like regen on the capacitors. The small current
flowing through the bybass resistors cannot provide equalization if you
charge with 1000 amps. As I have seen most providers of high capacity
ultracapacitors recommend active equalisation, and the circuit is
exaclty like the one you use for the TS lithiums - a voltage clamper.
Emil
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Power vs. weight on these eCycle BLDC motors seems really good. My
question is, how does one get their hands of one of these? eCycle's
website lists Infranor as their only distributor. Infranor's website
does not mention these MG series motors at all, only their new
"electronic commutator" motors (which are interesting in their own
right).
Also, are there other manufacturers with comparable products, for
someone looking for a lightweight, efficient generator?
--c.r.
On Tue, 2004-09-28 at 22:34, Doug Hartley wrote:
> Bill Dennis wrote:
> > Does the generator hook
> > up to the battery pack looking like just another power source in parallel?
> Yes, with a circuit breaker for protection and disconnect when working on
> it, and an Ammeter shunt in series with one of the connections.
>
> I am using eCycle Permanent Magnet Brushless DC motors spun by Honda
> engines, with a 3-phase diode bridge to produce DC directly, like an
> alternator. Using a 120VAC single phase standard home power generator would
> not be as efficient, nor allow the voltage and current output to be adjusted
> directly with governed engine RPM.
>
> > If so, let's say someone installs a 10kW generator. If the car is drawing
> > only 9kW of power, does 9kW go into the motor, and the other 1kW go into
> > charging the battery pack?
> With the type of generators I am making, generally the engine RPM can be
> adjusted to provide some battery charging under light load. Since I have
> only made 5kW units so far (still waiting for my 14kW MG3-36LC), charging
> only occurs at very light load. The 14kW unit will be able to maintain a
> higher battery charging voltage level much of the time. A "10kW generator",
> even of the type described above, would only supply 10kW under certain load
> conditions it is perfectly matched for. If you reduced the load current,
> the voltage would probably not go up by the same percentage to keep the
> power constant. In fact, you wouldn't want it to behave like this, as it
> would be too easy to overcharge the batteries under light load. How much
> the voltage rises as the load is dropped would depend if the engine was
> overloaded and not able to make its set speed, and then with lighter load it
> will speed up. One of the advantages of this type of PM BLDC 3-phase
> generator is that the voltage output is dependent on RPM, with some drop
> according to the load. If you have some reserve speed and torque available
> from the engine, you can advance the speed setting to increase the voltage
> more to charge the batteries. There are lots of variables to consider as
> the batteries can be at differing states of charge at different times, and
> the motor load current is varying also as you drive. It is not like running
> a light bulb off a 120VAC generator that has a regulated, nearly fixed,
> output voltage and the bulb draws a fixed current at that constant voltage.
>
> An important consideration is that BLDC motor/generators are available in
> certain discrete voltage output choices (Volts per 1000 RPM rating -
> multiply by 3 to get a rough realistic estimate of output at 3600 to 3900
> RPM) and battery packs come in discrete voltage values, jumping by 6 or 12V.
> The single stack 5kW size has the most voltage choices, so lets take a look
> at 3 practical examples of design using my 84V to 96V vehicles:
>
> Try an eCycle MG-24, Back EMF of 25.5V/1000 RPM and 57A max, highest Amps
> and lowest torque per Amp required: At 3600 RPM, only about 74V output at
> useable current, and that is not enough voltage. However, if you overspeed
> the engine a lot, you can get say 93 V at 15 A for charging a low battery
> pack, and 80- 84V at much higher current, depending on engine torque
> available, for driving. That doesn't sound like a good idea, but if you
> have only a small engine, like a 5HP GC-160, and want a light compact unit,
> using the MG-24 at high RPM would be the way to get the most current from
> this engine. This is true because it gives more current than a higher
> voltage MG for the torque this engine can produce, and you are getting
> relatively high power out of a small engine.
>
> How about the next voltage up, an MG-30? This is a better choice, rated at
> BEMF 31.8V/1000RPM and 47A maximum. Couple it to a 6.5HP GX-200 and you can
> have up to 35A charging without overreving as much, and 50A running at 84V
> (sandwich a large thick aluminum plate to the MG-30 for heat sinking when
> mounting it). This is what I have now under the back of the Skoda pickup.
> It matches well to 93V TS Li Ion sagging down to 84V AGM batteries support.
> Set the speed lever to max and it will charge a low 84V pack or my hybrid
> pack, at about 35A and provide more than 50A under load (driving). With a
> fairly discharged battery pack and high motor load, the engine speed setting
> should be reduced.
> Couple the newer generation MG-30 with good added cooling to a GX-270 9HP
> and you could probably get near to 6 kW out. I have one of these to try
> when I find some time, and spare money to buy the 9HP engine. Once built,
> it will probably get installed in the pickup to provide a small power
> upgrade over the existing 2002 model MG-30 and 6.5HP engine.
>
> Or an MG-36? BEMF 38.3V/1000RPM and 40A maximum. For an 84V system, the
> engine would have to be run slower, developing less power than with the
> MG-30, to provide the correct voltage range. Current output would be lower,
> which makes sense, since there is less input power from the engine and
> considering the lower current limit of the MG-30. So both the engine and
> MG-30 would not be delivering the output they are capable of.
> But for a 96V system, the MG-36 would be near perfect: Raise the engine
> RPM and get about the full rated output of both the engine and the MG-30.
>
> For higher voltage battery packs, there are not as many choices: the MG-48,
> BEMF 51.5V/1000 RPM, 29A and MG-62, BEMF 65V/1000 RPM and 24A.
> The MG-48 would probably be optimum for a 144V pack and the MG-62 good for a
> 180V system.
> If you have a 120V battery pack/system, you would need to use the MG-48, but
> at lower RPM and power rating, so as to operate at the correct lower
> voltage.
>
> The larger eCycle 10kW and 14kW sizes have less choices as the power and
> size are increased. All sizes have an MGx-36, so I am well supported with
> my 93 and 96V systems. You might find some other manufacturer's BLDC unit
> that has Voltage output and current in-between an MG-30 and an MG 48, that
> you could use at 3600 - 3900 RPM on a 120V system. Or maybe not. But you
> can see from the above how it goes and the design exercise needed to choose
> the motor/generator unit suitable for your EV battery voltage. Perhaps it
> would be better to do this early and choose the battery pack voltage
> according to the available generator choices.
>
> HTH
> Doug
>
> ----- Original Message -----
> From: "Bill Dennis" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Tuesday, September 28, 2004 3:12 PM
> Subject: RE: Thunder Sky & AGM hybrid pack Re: Thundersky Lithium
>
>
> > Thanks for the good info (again), Doug. I have a question about your
> > generator--actually, generators in EVs in general. Does the generator
> > hook
> > up to the battery pack looking like just another power source in parallel?
> >
> > If so, let's say someone installs a 10kW generator. If the car is drawing
> > only 9kW of power, does 9kW go into the motor, and the other 1kW go into
> > charging the battery pack?
> >
> > Thanks.
> >
> > Bill Dennis
> >
> >
>
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