EV Digest 2819
Topics covered in this issue include:
1) Re: Smoke in your face (was Re: High $ Porsche Conversion part three)
by "damon henry" <[EMAIL PROTECTED]>
2) Re: Lithium battery monitoring
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Lithium battery monitoring
by "John G. Lussmyer" <[EMAIL PROTECTED]>
4) Re: Batteries
by "Mark Thomasson" <[EMAIL PROTECTED]>
5) Re: Batteries
by Jim Coate <[EMAIL PROTECTED]>
6) Thanks Victor
by Jeff Shanab <[EMAIL PROTECTED]>
7) RE: SCCA classes
by Jeff Shanab <[EMAIL PROTECTED]>
8) LiIon battery charge/discharge graphs
by "Gary Graunke" <[EMAIL PROTECTED]>
9) NEDRA Power of DC Drag Race just a month away
by Chip Gribben <[EMAIL PROTECTED]>
10) Battery pack sizing questions
by "Ralph Merwin" <[EMAIL PROTECTED]>
11) Re: Price for a 120 mile range performance oriented car weighing2000 pounds
by Lee Hart <[EMAIL PROTECTED]>
12) Re: Thunder sky chargeing
by Lee Hart <[EMAIL PROTECTED]>
13) Re: Lithium battery monitoring
by Lee Hart <[EMAIL PROTECTED]>
14) Re: Batteries
by Lee Hart <[EMAIL PROTECTED]>
15) RE: Thanks Victor
by "Bryan Avery" <[EMAIL PROTECTED]>
16) Re: Theory of Contactor Controllers (pictures)
by Lee Hart <[EMAIL PROTECTED]>
17) The crackpot index
by Peter VanDerWal <[EMAIL PROTECTED]>
18) Water for the batts
by "Mike Brandon" <[EMAIL PROTECTED]>
19) Re: LiIon and NiZn battery charge/discharge graphs
by "Joe Smalley" <[EMAIL PROTECTED]>
20) Re: Lithium battery monitoring? ...
by "Joe Smalley" <[EMAIL PROTECTED]>
--- Begin Message ---
The nameplate says AC4-4002 72V
From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
To: <[EMAIL PROTECTED]>
Subject: Re: Smoke in your face (was Re: High $ Porsche Conversion part
three)
Date: Wed, 28 May 2003 19:23:19 -0700
Is that 6.7 an A89 ADC motor? Lawrence Rhodes.....
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----- Original Message -----
From: "damon henry" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, May 28, 2003 10:20 AM
Subject: Re: Smoke in your face (was Re: High $ Porsche Conversion part
three)
> Well to be honest I don't know the answer to some of these questions.
For
> gearing I decided to start with the stock gearing so I am using the same
> sprockets that came on the motorcycle. I am considering trying a larger
> gear on the back wheel to give me a little more acceleration. I
wouldn't
> mind a bit better 0-20 speed and one thing that I have not tested yet
but
am
> worried about is starting from a dead stop on a hill. Once I get up to
> about 20mph it pulls real nice up to about 50 and then takes a little
more
> time to get up to 60. I did figure out that at 60mph my motor should be
> turning about 2600 RPMs which is probably a bit low for this motor
> considering that most of my riding will be done at lower speeds. I
haven't
> weighed the bike but it is not light. With 108lbs of lead, and 50 lbs
of
> motor the bike is probably around 350 - 400 pounds. I am 6'3" and 245
> pounds so I add quite a bit of weight and aero drag. If I were to go
with
4
> MB80's for my final pack that would add about another 50 pounds. I
> currently have three instruments to look at, my DMM reading the pack
voltage
> a clamp on ammeter watching the battery amps and my speedometer. It's
hard
> to keep an eye on all three and pay attention to what is going on around
me,
> but it seems like right now I can cruise at 40mph pulling ~90amps and
50mph
> ~120 amps. The road where I am testing has a slight grade to it, so I
have
> to look at what it takes going down hill and compare that against what I
see
> going the other way. I'm not sure exactly how changing the gearing will
> affect these numbers. On the one hand I would expect it to lower my top
> speed, but since I have never seen more then 250 amps and my current
pack
> sags down to around 43 volts during acceleration maybe the new ratio
would
> allow the volts to stay a bit higher. My controller is a 275 amp
curtis,
so
> I seem to have some more head room on current, plus there is still quite
a
> bit of fine tuning to do to the bike. So it may be possible to get
better
> low speed acceleration and keep my 60mph top speed. I also know that my
> brushes are currently set to neutral. I am not sure how adjusting these
> might change things. The other option that I am considering still is
going
> to 72V. With the performance I am seeing right now I am sure that 72V
would
> be scarey fast, but that would mean buying a new controller, and I'm not
> sure I want to spring for that. The current performance isn't bad. The
> only thing that I am really worried about is those times when I turn
left
> into the flow of traffic only to realize that there is a car coming
somewhat
> faster then I first thought, I don't feel like I have much umph at that
> point to get me out of the way. Also I still need to find a good hill
to
> test acceleration from a dead stop on. It is very likely that I will
leave
> everything just as it now is, but you know you've always got to tinker.
Oh
> yeah I am running one of the surplus Tropcica motors. They are ADC 6.7
inch
> although I believe they are an out of production version. I think the
name
> plate rating is 96V (could be 72) and I think they are rated around 7HP
> continous and 30hp peak. My current setup seems to be using 5-6 hp to
> cruise at 50. I have not ran at 60 long enough to get a feel for what
that
> takes. The roads around my house that I do my test runs on are mostly
45
or
> lower speed limits, so I don't have much of a chance to cruise at 60 I
have
> just verified that I can accelerate to that speed.
>
> damon
>
>
> >From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
> >Reply-To: [EMAIL PROTECTED]
> >To: <[EMAIL PROTECTED]>
> >Subject: Re: Smoke in your face (was Re: High $ Porsche Conversion part
> >three)
> >Date: Wed, 28 May 2003 00:41:20 -0700
> >
> >I was wondering what kind of gearing, weight and motor your bike has.
> >(website?)I am kind of disapointed in my performance with the 400 amp
> >Curtis
> >and 48v with the A89. It is ok in the hill climbing area but not so
great
> >in acceleration or top speed. Lawrence Rhodes......
> >
> >
> >----------------------------------------------------
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> >
> >----- Original Message -----
> >From: "damon henry" <[EMAIL PROTECTED]>
> >To: <[EMAIL PROTECTED]>
> >Sent: Tuesday, May 27, 2003 10:31 AM
> >Subject: Smoke in your face (was Re: High $ Porsche Conversion part
three)
> >
> >
> > > >objectionable. Driving behind an electric car is quite nice,
really;
> >I'm
> > > >thinking, hey, this guy is not belching smoke in my face.
> > >
> > > Ummm, this isn't necessarily true, let me 'splain.
> > >
> > > The other night I spent a couple of hours tinkering on Sparky my 48V
> >1974
> > > Suzuki GX250, at the Wayland EV juice bar. I had finally received
my
> >new
> > > speedo cable so I was actually able determine what speed I was
riding
> >at.
> > > Although the 4 Hawker GE16P's that made up my test pack were making
a
> > > valliant effort, especially considering that they had spent their
life
> >up
> >to
> > > this point riding in the back of "White Zombie" trying desperately
to
> >hold
> > > themselves together as they belted out 800 amps in 13 second bursts
and
> > > occasionally witnessed one of their "pack buddies" explode, they
were
> >not
> > > able to get me to my goal of 60mph as the voltage was sagging down
to
37
> > > volts by the time I hit 54mph. The solution was to grab 4 more of
these
> > > same batteries and wire them up in parallel. The batteries
themselves
> >were
> > > happy to join a new kinder regime and only let out one small spark
of
> > > dissension during the wiring process which hardly bares mentioning
after
> >the
> > > well documented yet unsuccessfull "Plasma Ball Revolt" a few years
ago
> >as
> > > they tried to free themselves from the evil dictator who was
routinely
> > > torturing them all the while proclaiming to the world that they
enjoyed,
> > > indeed thrived under these conditions. A more leisurely life of
> >occasionall
> > > 250+ amp discharges in the open air of a classic motorcycle frame
did
> >not
> > > seem like such a bad gig and they now routinely take me over the
60mph
> > > threshhold I have been seeking, but I get ahead of myself.
> > >
> > > Once the wiring was done John started tempting me with a test run up
one
> >of
> > > Portlands major surface streets. This would not have been a problem
> >other
> > > then the fact that I don't yet have any of the twelve volt system
wired
> >up
> > > thus no headlight, brake lights, or blinkers, not to mention the
fact
> >that
> > > the bike has no plates and I have not yet gotten my motorcycle
> >endorsement.
> > > John could see the weakeness in my resolve, however, in fact
probably
> >knew
> > > that I had been planning on doing this very thing the whole time
anyway
> >else
> > > why would I have brought my helmet? I put up a weak fight which he
> >quickly
> > > beat down then grabbed his digital camera so he could snap some
photos
> >as
> >he
> > > rode silently along side me in Blue Meanie. I questioned him about
> >local
> > > police patrols which he claimed to have no control over besides he
said
> >it
> > > would be fun explaining to the police exactly what we are up to.
Now
> >you
> > > see what kind of a twisted deviant my batteries have been subjected
to.
> > > When questioning what our route should be he suggested that we head
East
> >on
> > > Glisan which would take us right past the police station. By this
time
> >I
> > > had no will power left, not so much because John was pressing the
issue,
> >but
> > > because I was dying to try out the new pack so we headed out for a
> >little
> >EV
> > > test run. As we turned out of John's street onto Glisan and began
to
> > > accelerate up to speed John pulled up beside me a started snapping
> >photos.
> > > Before we could get going to fast a red light came up and we chatted
as
> >we
> > > sat there waiting for green. It was getting late in the evening,
but
> >there
> > > was plenty of traffic out and we where right in the middle of it.
The
> >light
> > > changed and we were off again. This time there where no more lights
> >coming
> > > up for a while so we were able to accelerate up to full speed.
Traffic
> > > settled in at about 50mph and I was right in the middle of it. This
was
> >the
> > > first time I had been surrounded by traffic like this and with
plenty
of
> > > pull left in the motor I was feeling confident. That silly thing
that
> > > happens to all of our faces started to spread across my mine. Man,
this
> >was
> > > a lot of fun. After riding with traffic for about a half mile I
made
a
> > > right hand turn and John followed. We cut through a neighborhood
and
> >headed
> > > back west towards John's house on Burnside. On Johns side of town
> >Burnside
> > > has it's eastbound and westbound lanes split by Portland's electric
> >light
> > > rail system. As we pulled out a train was coming and for a while
all
> >three
> > > Ev's where gliding along silently together. We returned to John's
house
> >and
> > > plugged into his ugly box charger to returned some of the used amp
> >hours.
> > > The four new batteries had not been excercised for a while, so we
knew
> >they
> > > would be even stronger on the next run. This time we decided to go
even
> > > further. This time we would go east until we made it to John Tuss's
> >house.
> > > This would be a round trip of about 4 miles. It was basically the
same
> > > route as before but John Tuss lived further east then I had take us.
> >This
> > > time John lead the way. I followed him on Sparky once again
enjoying
> >the
> > > pull of the electric motor and the feeling of being surrounded by
> >traffic
> > > but having no problem keeping up. We knocked on Tuss's door only to
> >find
> > > that we had woken him up. No problem he assured us, and came out to
> >enjoy
> >a
> > > few minutes worth of chat about the new project and unplug his
electric
> > > truck. We said goodbye and that's when it happened, although I
admit
he
> >at
> > > least gave me warning first. John thought I would enjoy the view
and
> > > apparently the smell of Blue Meanie smoking the tires from a
motorcycles
> > > perspective. As we headed back out on Burnside John let loose with
some
> >of
> > > the 1200 DCP Raptor's amps that he has available leaving two big
black
> >marks
> > > on the rode and a cloud of smoke for me to ride through. The smoke
> >filled
> > > my helmet and my nose, and though I know John has a hard time
believing
> > > this, not everyone enjoys the smell of burnt rubber as much as he
does.
> >So
> > > next time you are following behind a stinky gas powered ICE just
> >remember
> > > that if you happen to be following behind John Wayland in Blue
Meanie,
> >you
> > > may be in for just as bad of a smell.
> > >
> > > damon
> > >
> > > _________________________________________________________________
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> >
>
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--- End Message ---
--- Begin Message ---
Michael Hills wrote:
> There's been a lot of talk about building load banks and possibly
> driving around the block forever at low speed to break in these
> new Li-Ion batteries.
>
> It occured to me that since the PFC-20/50 can run off of DC with
> very little modification, why not just split the pack of Li-Ions
> in half and shuttle a charge back and forth. Charge one half off
> AC, then charge the second half from the first half.
It's a good idea. In fact, it works well for cycling lead-acid
batteries.
But there's a problem with these LiIons. They aren't all alike, and they
are behaving quite differently on each of these conditioning
charge/discharge cycles.
When you discharge them in series, some cells will reach 'dead' before
the others. How are you going to stop discharging it, and finish
discharging the rest?
And on charge, they reach 'full' at considerably different amphour
capacities. How are you going to stop charging the ones that reach
'full' first, and keep charging the rest?
These initial conditioning cycles can be partially performed in series,
but you'll have to finish each one separately somehow.
John Lussmyer's regulators can do it as long as their resistive loads
have enough current capacity. Once I've finished my conditioning cycles,
I may be able to see how much capacity this will be.
> One issue would be the initial state of charge.
Mine all arrived dead.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
At 10:04 PM 5/28/2003 -0700, Lee Hart wrote:
When you discharge them in series, some cells will reach 'dead' before
the others. How are you going to stop discharging it, and finish
discharging the rest?
Hmm, you know, I could program a "Discharge Cycle" into the regs to use the
loads to perform a discharge. Fairly low current (Like a bit under 5A) but
it would have individual Cell level control.
Maybe I'll discharge via big load until the first one reaches it's
"discharged" voltage, then let the others complete using the reg load bank.
And on charge, they reach 'full' at considerably different amphour
capacities. How are you going to stop charging the ones that reach
'full' first, and keep charging the rest?
Of course, in my case, that's what the regs are for.
John Lussmyer's regulators can do it as long as their resistive loads
have enough current capacity.
A single reg can dissipate about 5A - think. Depends on how hot I let the
big ceramic resistor get. Of course on these regs, I realized that I can
just add a 2nd, 3rd, 4th, etc.. Load bank to each reg unit and increase
the dissipation capability.
I'd just have to run a set of jumpers (6 wires) from the reg to each load
bank. Quite easy.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream.... http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
With the scheme below, I wonder about the energy lost while passing through
two sets of batteries. How much is lost from charge to discharge? If you
only get say 80% of the energy back that you put into one set of batteries,
passing it through two sets means you only get 64% back!
Using super capacitors for the performance pack would be much more efficient
(and expensive at today's prices).
What if you run each pack (performance and range) on separate PWM
controllers in parallel to the motor. Set the control pots so the range
pack provides a current limited base while the performance pack provides
current over that limit. It would be very interesting to determine the
optimum balancing of load between the two packs to provide the optimum
energy recovery, battery life, and performance. You're stuck with the cost
of two controllers with this scheme, but no double charging with the same
energy. Also, both packs would need to be close in voltage. Would this be
a problem?
What if the performance pack is a cheaper set of auto starting batteries,
something designed for intermittent high loads? Abuse them in peak load
conditions, never discharge them below 50%, and recycle them every year.
Thanks for any feedback you have to offer, Mark T.
>
> Or, do you feel ambitious? We've discussed hybrid battery packs on a
> number of occasions (one pack for performance, one for range). You could
> use 120v of Optima YTs, plus 48v of 6v T-105s. You'd have ~1000 lbs of
> lead for better range while still within the GVWR. You'd then use a
> DC/DC boost converter to step up the 48v to 120v. The boost converter
> would be set up to deliver relatively constant power to the 120v pack,
> so the floodeds don't have to deliver high currents. The Optimas deliver
> the high peak currents, but then get recharged by the floodeds when
> coasting, decellerating, stopped, or driving slow. That's the theory,
> anyway.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
>
>
--- End Message ---
--- Begin Message ---
And NiCads are happy in the cold winters so range consistent throughout
the year.
If anyone has an in with SAFT to find out how often the 680 amps for 10
seconds can be repeated, it would be most useful information.
Philippe Borges wrote:
Why not a 120V 140A/h Saft ni-cad pack ?
Though, it would be 800 pound for complete (nickel plated connection,
central watering system+box)
20 X 6V modules.
You will have largely the range you need, good life cycle and Saft
guarantied 270A constant/
680A (10sec) current for fun driving.
Philippe
Et si le pot d'�chappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
_________
Jim Coate
1992 Chevy S10
1970's Elec-Trak
http://www.eeevee.com
--- End Message ---
--- Begin Message ---
I thought they might because they call them "solid state" and talk
about "connecting boards" The user manual document appears to be auto
translated, the wording is real screwy. Saft has some lithium ion's with
unbelivable specs and have modules with some circutry in them also. They
are probably a tad expensive.
Just a though: if we were set up on flooded to circulate the electrolyte
we could circulate during charging to prevent the layering from varing
density and reduce the end of charge equalization time and energy. and
circulate during operation to control temperature. (care would be taken
to isolate electrolyte, ie. second exchanger at end of bat-box)
Has anyone "rolled their own" battery? Could making 1 big box of cells
save some of us some weight and money?
--- End Message ---
--- Begin Message ---
I am in Fresno california which is in the san francisco SCCA region. I
haven't autocrossed in a few years. My goal with the truck is to make
something fast and light wih a short (~40 mile daily) flatlanders range.
Autocrossing is all about how fast you can change speed and direction,
weight is a liability. I want to make the statement that electric isn't
neccasarrily slow, but I also want to commute with it daily. The hybrid
pack idea sounds very interesting. Kinda like very sturdy capacitors.
:-) The litium ion looks like a dream, the evercels a good middle
ground, YT's are just to heavy
--- End Message ---
--- Begin Message ---
Thanks to Chris Brune, I have a graph of the charge and discharge cycle for
a ThunderSky LiIon 90AH cell.
There was an adjustment to the charger on the charge cycle (this was the
first run), so that accounts for the dip just before 5000 seconds. The
charge was stopped at 1.2A so we didn't have to run it through the night
unattended. The total charge time was just under 6 hours, so perhaps it was
partially charged. The peak temp was 31C just after it reached 4.25 V (the
CV point was 4.25V). We're trying to be a bit conservative and not head
right to the 4.3V line for the first charge. The total AH in was about 77AH.
The graphs are in PDF format, available on my web server.
Charge cycle: http://ev.whitecape.org/lion/Cell89Charge5-27-03.PDF
About twelve hours later, a constant current 27A (.3C) discharge was run.
The stop voltage was 3V (the thundersky recommendation) after 2 hours and 40
minutes. The total AH out was 71AH. By the end of the discharge, the
temperature had climbed streadily to just under 42C.
Discharge cycle: http://ev.whitecape.org/lion/Cell89Discharge5-28-03.PDF
Gary
--- End Message ---
--- Begin Message ---
Hello Drag Race Fans!!
The NEDRA Power of DC Race is just a month away on Sunday, June 29, 2003 and
we're gearing up for another exciting day of racing.
This will be our third race at the Mason-Dixon Dragway set among the rolling
hills in Hagerstown, Maryland.
Gates open at 9:00 am and racing starts at 1:00 pm till about 4:00 or 4:30
pm followed by the awards ceremony and our traditional race dinner in
Hagerstown. We'll also have new 2003 PDC T-shirts available.
If you are interested in joining us by racing your EV or just spectating and
hanging out with the gang that would be great. Contact Chip Gribben for more
information at [EMAIL PROTECTED] (301) 490-0657 and visit our website at
http://www.powerofdc.com for further information.
RACERS
Among the racers we are expecting:
1) Sean Lawless from Ohio with his Orange Juice electric dragster
2) NetGain Technologies Bad Amplitude Dragster (we're hoping NetGain can
make it)
3) Bob Salem and Dave Erb from Ohio with Bob's VW Truck
4) Darin Gilbert and his Pirahna Bike from Detroit
5 & 6) Central Shenandoah Valley Regional Governor's School with two cars, a
240-Z and a Porsche 914
7) Northeast High School from Greensboro, NC with their Volkswagen Golf
8) Charlie Garlow's OEM GM S-10
9) Bryan Murtha's OEM Electric Ford Ranger
10) Christopher Zach's US Electricar AC Prism
11) Chip Gribben's 156-volt Ford Escort
We're also expecting quite a few friends from the EVDL and EAA who will be
attending this year as well.
SPONSORS
We'd also like to thank this year's Sponsors and Contributors. We are still
accepting sponsors and ads for our race program.
KTA Services
EV Parts
Manzanita Micro
Metric Mind Engineering
Vanner Technologies
Bad Fish Racing
Electric Vehicle Association of Washington, DC
DIRECTIONS
>From Harrisburg, PA and Martinsburg, WV
If you are coming from Harrisburg or Martinsburg get on to Rt. 81 and follow
it to Hagerstown, Md.,� when you get to Rt. 70 go east towards Frederick,
Md.�� Follow Rt. 70 to EXIT 32A (Rt. 40). Get off that exit and follow Rt.
40 east for exactly 3.7 miles.� The track entrance will be on your right
side.
>From Baltimore, MD and Washington DC
If you are coming from Washington DC or Baltimore get on Rt. 270 or Rt. 70
and head towards Frederick, Md.�Once at Frederick get on, or stay on, Rt. 70
west towards Hagerstown.� Follow Rt. 70 until you reach Rt. 66 (Exit 35).�
Once at the bottom of the ramp turn onto Rt. 66 South,� go about 1/2 miles
until you reach Rt. 40 (you will see a Sheetz convienance store at the
intersection)� turn left (east) on Rt. 40 and go just another 1/2 mile, the
Dragstrip entrance will be on your right.
PS.... you will go by the same Sheetz Store that the directions above
reference.
ACCOMODATIONS
These are last year's prices so check for pricing and availability.
Days Inn - Hagerstown
900 Dual Hwy�����
Hagerstown, Md 21740
Phone (301) 739-9050 (800) 422-2754
$57/ night - single or double occupancy
Four Points - Sheraton Hotel
Contact: Heather Lopez
1910 Dual Hwy
Hagerstown, Md 21740
Phone: (301) 790-3010
E-mail [EMAIL PROTECTED]
$59 night
Hampton Inn
1716 Dual Hwy
Hagerstown, Md 21740
Phone: (301) 739-6100
E-mail [EMAIL PROTECTED]
$64/ single� $64/ double occupancy (up to 4 people)
Quality Inn
1101 Dual Hwy
Hagerstown, Md 21740
Phone: (301) 733-2700
$50/night
Ramada Inn Convention Center
901 Dual Hwy
Hagerstown, Md 21740
Phone: (301) 733-5100 Ext. 0
$60/night single-quad
Super 8 Motel
1220 Dual Hwy
Hagerstown, Md 21740
Phone: (301) 739-5800
Web: www.Super8.com
$42/night single-quad
Venice Inn
431 Dual Hwy
Hagerstown, Md 21740
Phone: (301) 733-0830 / (800) 2-Venice
$50/single-double ( Motel )
$60/single-double ( Hotel )
Hope to see you on June 29!!
Chip Gribben
Power of DC Racing Coordinator
http://www.powerofdc.com
[EMAIL PROTECTED]
(301) 490-0657
--- End Message ---
--- Begin Message ---
Last weekend I was once again standing in the garage looking at my
Geo Prizm with gaping holes in the trunk and engine compartment where
batteries used to live, and a pile of now dead batteries stacked to
one side and a pile of battery boxes to the other...
Battery choices are swirling in my head. Do I load the car up with
lead acid batteries, shooting for the magic 30% battery weight, or
do I try the Evercel NiZn batteries?
My goal is to have a pack sized so I don't use more than 50% of the
pack capacity for my normal commute. My 26 mile commute (mostly
freeway speeds) requires about 7-8kwh round trip. Charging at work
is not an option, so I'm looking at a 14-16kwh pack.
My car weighed 2800lbs when it had the SAFT NiCads (20, 28lb modules),
so I'm using 2240lbs as an 'empty' weight that includes the weight of
the battery boxes, controller, charger, etc.
A 156v pack of 45ah Optima Yellow Tops (13 buddy pairs, about 14kwh)
would weigh 1170lbs, making the car's total weight 3410lbs (about 34%
battery weight). It would also be about 100lbs shy of GVW. I would
be able to keep my DCP-600 though, and I might be able to reuse the
battery boxes from a prior rebuild. I'd also have to install battery
box insulation and heaters (which might be tricky with the design of
the old boxes).
Another option is a 192v pack of Optima group 31s (about 14kwh). 16 of
these would weigh about 960lbs, for a total vehicle weight of 3200lbs
(about 30% battery weight). I would have to replace the DCP-600 with
another controller like Otmar's Z1K, and I'd probably have to make new
battery boxes. I'd also have to install battery box insulation and
heaters. I can mount the Optimas in any orientation.
The Evercel option is most attractive weight-wise, but is also much more
expensive. A 211v pack (16, 13.2v batteries, about 18kwh) would weigh
768lbs. I'm not sure what a proper weight ratio would be. I think I
would need the higher pack voltage to stay under the Evercel's limit of
about 250amps continuous. I would have to replace the controller and
battery boxes. The Evercels must be mounted upright, which limits my
placement options.
I'm leaning towards the Optima group 31 option. It seems like a good
compromise between weight and cost, even if I have to replace the
controller. I have a PFC-20, which will handle all of the pack options
I'm looking at.
Before I go too much further with this rebuild I'd like to get feedback
on my logic. Is it reasonable to use a target pack capacity of 14-16kwh
and the 30% battery weight target as a basis for this rebuild? Do the
Optima group 31s really have a 75ah capacity? Would I reasonably expect
to get a 26 mile trip from this pack without discharging the pack much
beyond the 50% point? Or would it be better to use 18 batteries (they
may not fit into the car)?
Ralph
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Lawrence Rhodes wrote:
>
> Wouldn't the best measure be the hp it takes to sustain a given speed?
> Lawrence Rhodes......
Yes; this would be a good way to assess the relative difference between
approaches. You'd probably measure power input to the motor (volts x
amps) because that is far easier than power output (torque x rpm).
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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Peter VanDerWal wrote:
>
> > Optimas do not share cell environment, some flooded batteries might
> > have common electrolyte, but still battery-to-battery imbalance
>
> Huh??!? How would this work? Wouldn't a common electrolyte short out
> the cells in the battery?
Yes, the electrolyte is electrically "hot", so you can't just pipe it
from one cell to the next. You'd have a leakage path that would soon run
the cells dead.
Some batteries have done this anyway, either by accident or on purpose.
For example, Electrosource Horizons had poor inter-cell seals, which
leaked and produced a high self-discharge rate. Some automatic watering
systems can malfunction, produces liquid paths between cells.
Some very large batteries have had pumps to circulate the electrolyte
for cooling and equalizing purposes. When this is done, either the lines
have to be very long and thin (to increase the path resistance to a
negligible level), or they use a positive displacement pump with a
physical insulated break between the input and output sides.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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John G. Lussmyer wrote:
> Hmm, you know, I could program a "Discharge Cycle" into the regs
> to use the loads to perform a discharge. Fairly low current (Like
> a bit under 5A) but it would have individual Cell level control.
156 volts at 5 amps is 780 watts. That's a terrifying amount of heat to
release inside a battery box. You'd need a substantial amount of
airflow, or water cooling to get rid of it safely.
The way to do a discharge test is to have an external load dissipate
most of the energy. Then, given that you have individually
microcomputer-controlled networked regulators, write the software to
monitor each cell and "trim" its load with the individual resistors so
that all cells come down at the same rate; i.e. so they will all reach
'dead' at the same time.
Likewise, on charge, don't wait until the very end to switch in the
loads; if you do, then the loads have to handle substantial bypass
currents. Instead, compare the individual cell voltages, and load each
cell so as to make them all reach full charge at the same time. This
way, you can charge or discharge at a high rate, yet keep the heat
generated by the regulators low and very well spread out over time.
> Maybe I'll discharge via big load until the first one reaches it's
> "discharged" voltage, then let the others complete using the reg load bank.
>
> A single reg can dissipate about 5A - think. Depends on how hot I let the
> big ceramic resistor get. Of course on these regs, I realized that I can
> just add a 2nd, 3rd, 4th, etc.. Load bank to each reg unit and increase
> the dissipation capability.
> I'd just have to run a set of jumpers (6 wires) from the reg to each load
> bank. Quite easy.
Please, please, please do not underestimate what the heat from the load
resistors and the batteries themselves can do!!! 4 cells, surrounded by
free air, in a 68 deg.F ambient, with a 25 amp load get dangerously hot.
If something fails from the heat, and causes further shorts or damage,
you could have a major disaster on your hands.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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Mark Thomasson wrote:
> With the scheme below, I wonder about the energy lost while passing
> through two sets of batteries. How much is lost from charge to
> discharge? If you only get say 80% of the energy back that you put
> into one set of batteries, passing it through two sets means you
> only get 64% back!
80% is about right for lead-acid batteries.
> Using super capacitors for the performance pack would be much more
> efficient (and expensive at today's prices).
Supercapacitors don't even have 1% of the energy storage of batteries.
Their voltage varies dramatically with state of charge. Thus, the DC/DC
converter used to charge/discharge them must work over a very wide
range. For the time being, supercapacitors are only useful when you only
need the extra power for a few seconds.
> What if you run each pack (performance and range) on separate PWM
> controllers in parallel to the motor.
It helps to recognize that the two battery packs make it a hybrid
vehicle (a battery-battery hybrid :-) There are all the usual
tradeoffs you see in other hybrid vehicles -- series vs. parallel
hybrids, etc. Just as for other hybrids, theories abound, but nobody
really knows what control strategy is best.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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> translated, the wording is real screwy. Saft has some lithium ion's
with
> unbelivable specs and have modules with some circutry in them also.
They
> are probably a tad expensive.
I spoke with someone at Saft about 6 months ago and he told me it would
cost about $500K for a 336V pack of their Li-Ion batteries ($20K per
module. I don't recall the exact voltage of the modules off-hand, but
it's probably on their website). I had heard elsewhere that their
prices were a lot cheaper (although still insanely expensive), so maybe
he was just telling me this to get me to go away and leave him alone.
:-)
-Bryan Avery
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Lawrence Rhodes wrote:
> The first three contactors connect to the resistor in the same
> order as their controller brush. The positive contactor is always
> on feeding them. The last contactor is interupted by a relay.
It looks like the sort of EV controller that competent designers had
already quit using when Tom Edison was alive. Just resistors being
switched in series with the motor.
I would suggest you forget fixing it, and replace it with something
better. There are lots of small Curtis controllers around; that would be
straightforward. Or, build a more "modern" contactor controller, like
the ones the Citicars used, which switch the batteries in
series/parallel combinations to get the speeds, and only have one
resistor for starting.
> What is that relay (looks like a vacuum tube) doing?
Does it say "Amperite" on it, and some number like "36NO5"? I'll bet it
is a time delay relay. It has a heating element whose voltage rating is
the first digits (36v), a switch contact (NO for Normally Open, NC for
Normally Closed), and a time delay from when you power the heater until
the switch operates (5 for 5 seconds). It might be being used for
anything from a delay to prevent you from going from a dead stop to full
speed instantly, to a flasher for turn signals.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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>From time to time we get folks posting "Amazing Discoveries" or "New
Technologies" on the list that are a bit beyond reality.
I just came across the Crackpot Index by mathematician John Baez. Since
it seems particularly appropriate to some of the things that get posted
on the list, I thought I'd pass it on.
THE CRACKPOT INDEX
A simple method for rating potentially revolutionary contributions to
physics.
1. A -5 point starting credit.
2. 1 point for every statement that is widely agreed on to be false.
3. 2 points for every statement that is clearly vacuous.
4. 3 points for every statement that is logically inconsistent.
5. 5 points for each such statement that is adhered to despite careful
correction.
6. 5 points for using a thought experiment that contradicts the results
of a widely accepted real experiment.
7. 5 points for each word in all capital letters (except for those with
defective keyboards).
8. 5 points for each mention of "Einstein", "Hawkins" or "Feynmann".
9. 10 points for each claim that quantum mechanics is fundamentally
misguided (without good evidence).
10. 10 points for pointing out that you have gone to school, as if this
were evidence of sanity.
11. 10 points for beginning the description of your theory by saying how
long you have been working on it.
12. 10 points for mailing your theory to someone you don't know
personally and asking them not to tell anyone else about it, for fear
that your ideas will be stolen.
13. 10 points for offering prize money to anyone who proves and/or finds
any flaws in your theory.
14. 10 points for each statement along the lines of "I'm not good at
math, but my theory is conceptually right, so all I need is for someone
to express it in terms of equations".
15. 10 points for arguing that a current well-established theory is
"only a theory", as if this were somehow a point against it.
(I would add: 10 points for arguing that a theory is old so we must be
able to improve upon it.)
16. 10 points for arguing that while a current well-established theory
predicts phenomena correctly, it doesn't explain "why" they occur, or
fails to provide a "mechanism".
17. 10 points for each favorable comparison of yourself to Einstein, or
claim that special or general relativity are fundamentally misguided
(without good evidence).
18. 10 points for claiming that your work is on the cutting edge of a
"paradigm shift".
19. 20 points for suggesting that you deserve a Nobel prize.
20. 20 points for each favorable comparison of yourself to Newton or
claim that classical mechanics is fundamentally misguided (without good
evidence).
21. 20 points for every use of science fiction works or myths as if they
were fact.
22. 20 points for defending yourself by bringing up (real or imagined)
ridicule accorded to your past theories.
23. 20 points for each use of the phrase "hidebound reactionary".
24. 20 points for each use of the phrase "self-appointed defender of the
orthodoxy".
25. 30 points for suggesting that a famous figure secretly disbelieved
in a theory which he or she publicly supported. (E.g., that Feynman was
a closet opponent of special relativity, as deduced by reading between
the lines in his freshman physics textbooks.)
26. 30 points for suggesting that Einstein, in his later years, was
groping his way toward the ideas you now advocate.
27. 30 points for claiming that your theories were developed by an
extraterrestrial civilization (without good evidence).
28. 40 points for comparing those who argue against your ideas to Nazis,
stormtroopers, or brownshirts.
29. 40 points for claiming that the "scientific establishment" is
engaged in a "conspiracy" to prevent your work from gaining its
well-deserved fame, or suchlike.
30. 40 points for comparing yourself to Galileo, suggesting that a
modern-day Inquisition is hard at work on your case, and so on.
31. 40 points for claiming that when your theory is finally appreciated,
present-day science will be seen for the sham it truly is. (30 more
points for fantasizing about show trials in which scientists who mocked
your theories will be forced to recant.)
32. 50 points for claiming you have a revolutionary theory but giving no
concrete testable predictions.
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Ok, here's a really basic question. I have had Neon's VW pickup for
about a month. I'm thinking I should check and maybe add water.
Can someone give me some do's and don'ts?
Like, how do I know if I need water? And how much do I add?
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Thanks, Gary. It looks like we are getting some data out on these new
batteries.
I have about 40 cycles on the MB100 and I expect to publish the curves when
I hit 50 cycles sometime next week. The capacity varies about 4 AHr from
cycle to cycle and I have not discovered the independent variable yet.
Keep charging.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Gary Graunke" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, May 28, 2003 9:52 PM
Subject: LiIon battery charge/discharge graphs
> Thanks to Chris Brune, I have a graph of the charge and discharge cycle
for
> a ThunderSky LiIon 90AH cell.
>
> There was an adjustment to the charger on the charge cycle (this was the
> first run), so that accounts for the dip just before 5000 seconds. The
> charge was stopped at 1.2A so we didn't have to run it through the night
> unattended. The total charge time was just under 6 hours, so perhaps it
was
> partially charged. The peak temp was 31C just after it reached 4.25 V (the
> CV point was 4.25V). We're trying to be a bit conservative and not head
> right to the 4.3V line for the first charge. The total AH in was about
77AH.
>
> The graphs are in PDF format, available on my web server.
>
> Charge cycle: http://ev.whitecape.org/lion/Cell89Charge5-27-03.PDF
>
> About twelve hours later, a constant current 27A (.3C) discharge was run.
> The stop voltage was 3V (the thundersky recommendation) after 2 hours and
40
> minutes. The total AH out was 71AH. By the end of the discharge, the
> temperature had climbed streadily to just under 42C.
>
> Discharge cycle: http://ev.whitecape.org/lion/Cell89Discharge5-28-03.PDF
>
> Gary
>
>
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And a lot of light if you run them at 160 volts DC.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, May 28, 2003 10:08 AM
Subject: Re: Lithium battery monitoring? ...
> 45 100 watt light builbs are a LOT of wiring !!
> --
> Rich Rudman
> Manzanita Micro
> www.manzanitamicro.com
> 1-360-297-7383,Cell 1-360-620-6266
>
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