EV Digest 2821
Topics covered in this issue include:
1) Re: air conditioning efficiency & motor requirements
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Theory of Contactor Controllers
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
3) RE: Battery behavior
by "Andre Blanchard" <[EMAIL PROTECTED]>
4) Re: Efficiency numbers
by "Christopher Zach" <[EMAIL PROTECTED]>
5) Re: Lithium battery monitoring
by Zachary Zeliff <[EMAIL PROTECTED]>
6) Re: air conditioning efficiency & motor requirements
by Ben Bennett <[EMAIL PROTECTED]>
7) Re: air conditioning efficiency & motor requirements
by "Christopher Zach" <[EMAIL PROTECTED]>
8) Re: Battery behavior
by Michael Hoskinson <[EMAIL PROTECTED]>
9) Re: Batteries
by "Philippe Borges" <[EMAIL PROTECTED]>
10) Re: Efficiency numbers
by "Thomas Shay" <[EMAIL PROTECTED]>
11) RE: Efficiency numbers
by "Bryan Avery" <[EMAIL PROTECTED]>
12) Re: Thunder sky chargeing
by Victor Tikhonov <[EMAIL PROTECTED]>
13) Fw: Curtis controllers cheap.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
14) Re: Battery pack sizing questions
by Victor Tikhonov <[EMAIL PROTECTED]>
15) Re: Efficiency numbers
by "Eric Penne" <[EMAIL PROTECTED]>
16) Re: Efficiency numbers
by "Christopher Zach" <[EMAIL PROTECTED]>
17) RE: Efficiency numbers
by "Eric Penne" <[EMAIL PROTECTED]>
18) Re: Efficiency numbers
by John Lussmyer <[EMAIL PROTECTED]>
19) Re: were these LiIons blown? (Re: TdS Report #63:)
by Lin Tse Hsu <[EMAIL PROTECTED]>
20) Re: Ralph's Optimas vs. Evercels
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: Efficiency numbers
by "Eric Penne" <[EMAIL PROTECTED]>
22) Re: Efficiency numbers
by Peter VanDerWal <[EMAIL PROTECTED]>
23) RE: Efficiency numbers
by "James Jarrett" <[EMAIL PROTECTED]>
24) Re: air conditioning efficiency & motor requirements
by Peter VanDerWal <[EMAIL PROTECTED]>
25) Re: air conditioning efficiency & motor requirements
by Victor Tikhonov <[EMAIL PROTECTED]>
26) Re: Batteries
by Peter VanDerWal <[EMAIL PROTECTED]>
--- Begin Message ---
Alex Karahalios wrote:
> Last quoted price I saw from Sanden regarding there electric compressor
> and controller was around $3500.
When a big company makes something special and unique, it's bound to be
expensive. However, there is nothing all that special or unique about
wanting to drive an electric motor from DC.
What I would suggest is getting a good home air conditioner compressor.
The cheapest way to get it is probably to buy the whole air conditioner,
and just take out its compressor.
Then, get an industrial variable-speed AC motor controller, the kind
that allows you to vary the speed. We don't need to vary the speed; what
we really want is the inverter that can accept a DC input voltage an
generate normal AC to drive the compressor.
It won't be the ultimate in efficiency, but it will be a heck of a lot
better than running a DC motor to drive an automotive compressor.
--
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 ---
It looks like to me you are right about the contactors but as far as high
maintance I don't see it. All the parts are obviously original. I figure
just replacing the Contactor that over heated with something beffier will be
a good first step. The other two also but they might work with a smaller
contactor. I'll see. I think I can get it running for 75 bucks. Lawrence
Rhodes.......
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----- Original Message -----
From: "Joe Smalley" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, May 28, 2003 11:41 PM
Subject: Re: Theory of Contactor Controllers
> I think what happened was the current increase was significant enough that
> the contacts overheated. The design was probably high maintenance before
you
> got it.
>
> If the contacts only shorted out part of the resistor, they probably only
> saw less than 8 volts across them when switching. When you moved up to 48
> volts the voltage increased to 12 volts but the current may have doubled
> since the acceleration probably doubled as well. Since the delay was the
> same, the current did not fall during acceleration as much as it did at 36
> volts and the contactors were working much harder.
>
> The hardest thing you could do them would be to let off the throttle from
> full throttle to zero throttle at a very low speed. You would be breaking
> the largest current.
>
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> [EMAIL PROTECTED]
>
>
>
> ----- Original Message -----
> From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
> To: "Roderick Wilde" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> Sent: Wednesday, May 28, 2003 7:52 PM
> Subject: Re: Theory of Contactor Controllers
>
>
> > It is a little confusing. I still don't understand how 12v selinoids
can
> > take 36v for forty years and then fry when I take them up to 48v.
> Lawrence
> > Rhodes......
>
--- End Message ---
--- Begin Message ---
I will take a wild stab at an answer for this.
Assuming you are not talking NiCads.
The rest of the batteries in the string are still charging and increasing in
voltage and total pack voltage is increasing causing the current to drop.
Dropping current results in reduced voltage on the battery in question.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lawrence Rhodes
Sent: Thursday, May 29, 2003 12:24 PM
To: [EMAIL PROTECTED]
Subject: Battery behavior
When a battery comes up to target voltage and then drops in voltage below
all the other charging batteries what does this indicate? Battery feels
cool. Resting voltage is about .1 volt lower than other batteries. This
is a sealed battery. Lawrence Rhodes......
--- End Message ---
--- Begin Message ---
Let's both go for a drive. You in a 25mpg car, and me in my Prizm. Distance
of 25 miles.
ICE:
Fuel used: 1 gallon
Cost of fuel: $1.75 (today)
Cost for drive: $1.75
Prizm:
Power use on a 25 mile drive: 25 amps at 300 volts. About 300 watt hours per
mile.
Power used: 7,500 watt hours
(Let's assume I am using the MagneCharger:)
Charge efficiency: .90
Power used at outlet: 8.25 kw
Cost of power: 8c/kw hr
Cost to make 8.25 kw hr of power: 66 cents
So it costs me less to drive the electric car than the ICE car. You could
say the electic car is comparable to an auto that gets 66 miles per gallon
when the price of gas is 1.75 and the price of electricity. Bump the gas
price to 2 bucks a gallon, and the equiv "MPG" to compare would be 75mpg.
Chris
----- Original Message -----
From: "Eric Penne" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 1:27 PM
Subject: Efficiency numbers
> I've been doing some napkin calculations that I will eventually post to
> the list and put up on a website.
>
> According to my calculations which are very basic and estimate a lot:
> Gasoline car - 25 MPG city milage
> Gasoline $1.50/gallon
> Electricity $0.08/kWh
>
> Rough guesstimate for LiIon pack of 6800 Cycles to 25% DOD.
>
> There's more info and calculations but I basically came out with a 230
> Wh/mile figure for a BEV to have the same cost per mile as the above
> mentioned 25MPG city vehicle.
>
> Is 230 Wh/mile in the city a reasonable figure?
>
> Related:
> At 350 Wh/mile the same vehicle needed gasoline to jump to $2.71/gallon.
> Is 350 Wh/mile resonable for city driving?
>
> Eric
>
>
--- End Message ---
--- Begin Message ---
Hi, I'm new here.
One question.
How much ($) were the Lithiums per Ah?
Thanks
Zach
On Wednesday, May 28, 2003, at 20:56 US/Pacific, Rich Rudman wrote:
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. You'll have to make sure you battery monitoring
is set
up to shut down the PFC-20 when pack 1 is empty, but you'd need the
same
circuit to turn off the load bank. Then finish charging the second
pack off
of AC. Turn the PFC-20 around and repeat...
Rich, was a DC rated fuse on the input the only thing needed for the
PFC-20/50 to run off DC? Any reason you couldn't just give a
recommended
part number for people to buy, or is there more to it?
One issue would be the initial state of charge. If the batteries
arrive
mostly charged, you'd have to discharge at least half the pack in
some other
way first. I suppose if you have another EV you could use the PFC-20
to
drain the Li-Ions into that battery pack. Why boil away good
electrons if
you don't have to?
-Michael
_________________________________________________________________
Add photos to your e-mail with MSN 8. Get 2 months FREE*.
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Good idea.
But you will loose only the waste from the charger and the Cells them
selves.
You would save about %80 of the energy that you would if you just blew
it off and them sucked from th grid.
DC fuse, and enough to light up the 15 volt switcher for logic and
fans. If a solid 15.0 volts dropped righ into the 15 volt rail DC
connector is used then Well it works from about 6 volt up.
They all get tested with a Chicken power supply before I let Big AC
touch the on board supply. I wanna KNOW the silicon is working before I
dump 240 grid on $750 worth of hardware.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
Zachary Zeliff
Apple Product Design Engineer
Office: 408-974-6974
Cell: 408-368-8885 <--- In the States now
Taiwan Cell: 886-916690791
--- End Message ---
--- Begin Message ---
Isn't there a way to use a computer battery back up for
this? It seems to me it would every thing you'd need,
battery input, 110 VAC output?
--
I'm not mooning you, just turning the other cheek
Ben Bennett
http://home.earthlink.net/~greyhawk200/
--- End Message ---
--- Begin Message ---
300 volt AC input...
However to be honest the AC on my system pulls about 5 amps at 300 volts.
1,500 watts. I seem to recall the DC-DC converter on the Dolphin was rated
at some insanely high 12 volt output; maybe one could run it off that.
Would it be possible to pulse/switch 300 volts down to 36 volts and use an
Elec-Trak motor?
Chris
----- Original Message -----
From: "Ben Bennett" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 3:00 PM
Subject: Re: air conditioning efficiency & motor requirements
> Isn't there a way to use a computer battery back up for
> this? It seems to me it would every thing you'd need,
> battery input, 110 VAC output?
> --
> I'm not mooning you, just turning the other cheek
> Ben Bennett
> http://home.earthlink.net/~greyhawk200/
>
>
>
--- End Message ---
--- Begin Message ---
You using regs? When the regs read target voltage and start to
bypass, the voltage across the battery goes down until they stop
bypassing.
Mike
Lawrence Rhodes wrote:
When a battery comes up to target voltage and then drops in voltage below
all the other charging batteries what does this indicate? Battery feels
cool. Resting voltage is about .1 volt lower than other batteries. This
is a sealed battery. Lawrence Rhodes......
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--- End Message ---
--- Begin Message ---
Saft NiCads are quasi indestructible, we use a bunch of them on our Scooler
and go-kart since 5 years now, 0% failure and still strong at full amps.
Note: we have seen all mistakes a customer can do:
forget to fill the water in time, short them, wiring not perfectly tight, no
connector cleaning...
For the full amps, Saft data i have is near 700A during 10sec max if
conditions are bad = when they pass 25�C and/or under 5V/module BUT until
this limits you can stay at full amps !!! so on motor side you have plenty
of power to burn rubber !
What a pity cadmium is so crapy, Saft EV ni-cad are really (imho) the best
batteries we can count on for a moment.
though waiting for lithium or Ni-zinc...
The next Scooler would be French Ni-zinc powered.
Philippe
Et si le pot d'�chappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
----- Original Message -----
From: "Jim Coate" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 4:29 AM
Subject: Re: Batteries
> 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 ---
Recheck your calculations. 25mpg at $1.50 per gallon is 6 cents per mile.
6 cents per mile at 8 cents per kwhr is 750 whr per mile, not 230.
230 whr per mile is good performance. The EV-1 and the Sparrow use
about 200 whr per mile. A pickup conversion like my Ranger will use
about 500 whr per mile.
Tom Shay
----- Original Message -----
From: "Eric Penne" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 10:27 AM
Subject: Efficiency numbers
> I've been doing some napkin calculations that I will eventually post to
> the list and put up on a website.
>
> According to my calculations which are very basic and estimate a lot:
> Gasoline car - 25 MPG city milage
> Gasoline $1.50/gallon
> Electricity $0.08/kWh
>
> Rough guesstimate for LiIon pack of 6800 Cycles to 25% DOD.
>
> There's more info and calculations but I basically came out with a 230
> Wh/mile figure for a BEV to have the same cost per mile as the above
> mentioned 25MPG city vehicle.
>
> Is 230 Wh/mile in the city a reasonable figure?
>
> Related:
> At 350 Wh/mile the same vehicle needed gasoline to jump to $2.71/gallon.
> Is 350 Wh/mile resonable for city driving?
>
> Eric
>
>
--- End Message ---
--- Begin Message ---
>
> So it costs me less to drive the electric car than the ICE car. You
could
> say the electic car is comparable to an auto that gets 66 miles per
gallon
> when the price of gas is 1.75 and the price of electricity. Bump the
gas
> price to 2 bucks a gallon, and the equiv "MPG" to compare would be
75mpg.
>
Yes, but when you average out the cost and life of the battery pack over
each mile driven(which I think is what Eric was getting at), the
cost/mile goes up quite a bit. I was trying to figure this out the
other day as well, and my conclusion was that my cost/mile with the
li-ions would be equivalent to driving a car that gets 25 mpg and paying
a bit over $2.00/gallon for the gas. This was figuring a 100,000 mile
life of the battery pack and a projected 240 wh/mile. I haven't seen
any real data about the number of cycles possible on the li-ions at low
DOD's, so the 100,000 mile figure was just a guess. Eric, how did you
come up with the 6800 cycle figure? If 6800 cycles is reasonable, then
that would mean about 200,000 miles for the pack and would actually make
it cheaper over the long-run than a 25 mpg gas car.
-Bryan Avery
--- End Message ---
--- Begin Message ---
Perhaps you're right, it wouldn't, my bad.
Actually electrolyte conducts by ionic transfer, it must be
a good insulator for electrons, else electrolyte itself will short
the cell (traces of electron conductance are responsible for
self discharge).
Thinking of this, it crossed my mind that this would apply to
whole battery as well, and being unsure I wrote "might".
Thinking more - it probably indeed wouldn't apply.
Victor
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?
--- End Message ---
--- Begin Message ---
Found this on the net. Lawrence Rhodes....
Is this a good deal? Anybody have something used at a better price??????
> I have a factory remanufactured 1204X-5201 controller for sale. 36-48VDC
> 275amp. The unit comes with a full 2 year warranty. The price is
> $180.00 including shipping, which would be UPS ground. We accept Visa,
> MasterCard, AMEX.
> Thanks for your inquiry,
>
> Peter Hascher
> Sales Manager
> Alternative Fuels Equipment
> 20638 Krick Rd.
> Cleveland, OH 44146
> 800.772.4836
> 440-232-4111
> 440-232-9106 FAX
>
>
>
> -----Original Message-----
> From: Lawrence Rhodes [mailto:[EMAIL PROTECTED]
> Sent: Thursday, May 29, 2003 2:32 PM
> To: [EMAIL PROTECTED]
> Subject: Curtis controllers cheap.
>
>
> Do you have 48v 275 amp controllers? Lawrence Rhodes....
>
>
> ----------------------------------------------------
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>
>
>
--- End Message ---
--- Begin Message ---
Why not buy few same NiCds just to replace damaged ones? THis is the
only
expense then, no rebuilds needed. May be you can find used ones of
the same type.
Victor
Ralph Merwin wrote:
>
> 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
--- End Message ---
--- Begin Message ---
On a strictly electricity cost basis, getting better than 750 Wh/mile will
get the same cost per mile. If you count that a battery pack is usually
more than 50% of the cost per mile figure then you need to get
significantly better than 750 Wh/mile. Hence the 350 Wh/mile and 230
Wh/mile calculations. Looking back, my calculations "are" wrong but not
for the same reason.
Does your ranger use 500 Wh/mile on average or is that strictly city driving?
I'll be preparing a complete report with my assumptions and calculations
eventually. I want to get some good information on the NiZn, NiMH, NiCd,
and LiIon batteries in comparison to the flooded LA and optimas. Once I
get the spreadsheet/other setup it will be easier to add differences.
Currently for the Ah capacities I have been taking the published capacity
and dividing it by 2 for EV style current draws. It may be a little over
estimation.
> Recheck your calculations. 25mpg at $1.50 per gallon is 6 cents per
> mile. 6 cents per mile at 8 cents per kwhr is 750 whr per mile, not
> 230.
>
> 230 whr per mile is good performance. The EV-1 and the Sparrow use
> about 200 whr per mile. A pickup conversion like my Ranger will use
> about 500 whr per mile.
>
> Tom Shay
>
>
> ----- Original Message -----
> From: "Eric Penne" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, May 29, 2003 10:27 AM
> Subject: Efficiency numbers
>
>
>> I've been doing some napkin calculations that I will eventually post
>> to the list and put up on a website.
>>
>> According to my calculations which are very basic and estimate a lot:
>> Gasoline car - 25 MPG city milage
>> Gasoline $1.50/gallon
>> Electricity $0.08/kWh
>>
>> Rough guesstimate for LiIon pack of 6800 Cycles to 25% DOD.
>>
>> There's more info and calculations but I basically came out with a 230
>> Wh/mile figure for a BEV to have the same cost per mile as the above
>> mentioned 25MPG city vehicle.
>>
>> Is 230 Wh/mile in the city a reasonable figure?
>>
>> Related:
>> At 350 Wh/mile the same vehicle needed gasoline to jump to
>> $2.71/gallon. Is 350 Wh/mile resonable for city driving?
>>
>> Eric
>>
>>
--- End Message ---
--- Begin Message ---
Perhaps. Let's look at the battery pack:
Cost: $2,000 (I won't include shipping, my price)
Lifetime:
Well, that's tricky: The pack in my Prizm was from 1994; that's 10 years
old. It was however sitting dead for about 5 years; that didn't help it. In
terms of miles most of the Prizms in the fleet we were bidding on had 30-40k
miles on their packs, followed by sitting for 5 years or so. So let's say
40,000 miles.
So you have $2,000 divided by 40,000 miles=.05 cents per mile.
Ok, looking at it that way you pop up the cost by about $1.25 for the run.
However you're not counting the consumables in a car ICE over that time
period either. Or the fact that my pack costs twice as much as a T105 pack.
I can take a look in Quicken and see how much I spend on each car for
repairs over a time period; that moronic Caravan can cost a K a year if I
trusted the local dealer...
Chris
----- Original Message -----
From: "Bryan Avery" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 3:54 PM
Subject: RE: Efficiency numbers
> >
> > So it costs me less to drive the electric car than the ICE car. You
> could
> > say the electic car is comparable to an auto that gets 66 miles per
> gallon
> > when the price of gas is 1.75 and the price of electricity. Bump the
> gas
> > price to 2 bucks a gallon, and the equiv "MPG" to compare would be
> 75mpg.
> >
>
> Yes, but when you average out the cost and life of the battery pack over
> each mile driven(which I think is what Eric was getting at), the
> cost/mile goes up quite a bit. I was trying to figure this out the
> other day as well, and my conclusion was that my cost/mile with the
> li-ions would be equivalent to driving a car that gets 25 mpg and paying
> a bit over $2.00/gallon for the gas. This was figuring a 100,000 mile
> life of the battery pack and a projected 240 wh/mile. I haven't seen
> any real data about the number of cycles possible on the li-ions at low
> DOD's, so the 100,000 mile figure was just a guess. Eric, how did you
> come up with the 6800 cycle figure? If 6800 cycles is reasonable, then
> that would mean about 200,000 miles for the pack and would actually make
> it cheaper over the long-run than a 25 mpg gas car.
>
> -Bryan Avery
>
>
--- End Message ---
--- Begin Message ---
> Yes, but when you average out the cost and life of the battery pack over
> each mile driven(which I think is what Eric was getting at), the
> cost/mile goes up quite a bit.
This is what I was doing, including the battery pack into the cost/mile.
> DOD's, so the 100,000 mile figure was just a guess. Eric, how did you
> come up with the 6800 cycle figure? If 6800 cycles is reasonable, then
> that would mean about 200,000 miles for the pack and would actually make
> it cheaper over the long-run than a 25 mpg gas car.
>
> -Bryan Avery
I took a chance with an assumption (happy to make an ass of myself) and
extension of the Optima cycle life calculations. I know they are
different chemistries but I was just doing some very rough calculations.
A pdf on the commuter cars web sight says Optima YT's have about 250
cycles to 80% DOD in them. At 30% they have 3400 cycles available. The
Thundersky website says LiIon have about 500 cycles to 80% DOD so I
assumed using the Optima ratios that they would have 6800 cycles at 30%
DOD. I know it is a "HUGE" assumption but it is still an interesting
calculation for discussion. My 30% figures is purely based on my daily
trips of 7 mile to work and charging at work. Your daily stuff may be a
heck of a lot different.
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At 03:28 PM 5/29/2003 -0500, Eric Penne stated:
I'll be preparing a complete report with my assumptions and calculations
eventually. I want to get some good information on the NiZn, NiMH, NiCd,
and LiIon batteries in comparison to the flooded LA and optimas. Once I
get the spreadsheet/other setup it will be easier to add differences.
Currently for the Ah capacities I have been taking the published capacity
and dividing it by 2 for EV style current draws. It may be a little over
estimation.
Especially since the NiZi and LiIon don't seem to have much Peukert effect
equivalent at all. Note the recent results from the NiZi tests that were
posted.
With my Sparrow, I was barely getting 35 AH out of my YT's - and I'm pretty
sure that was taking them below 80%, with only a 60A or so average draw.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.Com
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> 1600 LiIons I assume AA size.
I'm positive, no per cell BMS
> was used, likely large groups
of cells were in parallel.
I believe you are correct. I'm
friends with Drew from the Clarkson
team and he spent some time
showing me their BMS
> I wouldn't be surprised if
this was the pack which blew
> (or was it the "sophisticated,
student-built charger"?
this was not the car that had
the fire, nor did the batteries "blow".
Their BMS used
undersized/underheatsinked FETs which started popping
one by one once the first one
went. As for the "sophisticated,
...
So, this was not the car which had the fire, in none
of the cars did the batteries blow, and this car's BMS
was cool, but it burned out, but did not "blew". :-)
Did everything "blow"?
Lots of FET's in parallel, probably not set up for
effective current sharing, and not current limited.
Likely to "blew".
Gosh, this stuff is unclear.
__________________________________
Do you Yahoo!?
Yahoo! Calendar - Free online calendar with sync to Outlook(TM).
http://calendar.yahoo.com
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--- Begin Message ---
Fred Whitridge wrote:
>
> Am trying to install a liquid cooling
> system beneath the batts, am waiting for my Brusa charger, and...
Going out tomorrow, you'll have it next week.
Victor
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My calculations using Optima YTs guessed 34.7Ah from the Optima which
equated to $3.55/gallon using $0.08/kWh. The Ah is probably too high then
in real life but there are so many variables in this picture that I just
can't look at right now. I figured I would get some preliminary stuff
going then fine tune it as I went.
The whole thing started when Bill Moore from EVWorld.com sent me an email
yesterday and all the stuff was jumbled in my head so I told myself that I
needed to write it down and organize it. So far so good.
> At 03:28 PM 5/29/2003 -0500, Eric Penne stated:
>>I'll be preparing a complete report with my assumptions and
>> calculations eventually. I want to get some good information on the
>> NiZn, NiMH, NiCd, and LiIon batteries in comparison to the flooded LA
>> and optimas. Once I get the spreadsheet/other setup it will be easier
>> to add differences. Currently for the Ah capacities I have been taking
>> the published capacity and dividing it by 2 for EV style current draws.
>> It may be a little over estimation.
>
> Especially since the NiZi and LiIon don't seem to have much Peukert
> effect equivalent at all. Note the recent results from the NiZi tests
> that were posted.
> With my Sparrow, I was barely getting 35 AH out of my YT's - and I'm
> pretty sure that was taking them below 80%, with only a 60A or so
> average draw.
>
> --
> John G. Lussmyer mailto:[EMAIL PROTECTED]
> Dragons soar and Tigers prowl while I dream....
> http://www.CasaDelGato.Com
--- End Message ---
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Well you could make it a fair comparison. Compare your electric Prizm
to a gas Prizm. Not a big difference since the combined mileage of a
gas prizm is roughly 30 mpg.
Also for general comparison purposes you should use the national average
price for gas and electricity (otherwise the numbers end up all over the
chart, i.e. east coast gas is $1.35 and electricity is $0.13, etc.)
The current national average gas price is $1.485 per gallon. I believe
the national average price on electricity is about $0.11.
Naturally as gas gets more expensive, or in areas where electricity is
particularly cheap, the scales tip more toward EVs.
I'd also like to point out that expecting to get 6800 cycles from Lions
sounds overly optimistic. It might be possible if you are only using
25% of your charge; however, that would indicate a life span of
approximately 20 years. There is a good possibility that Lions will die
of old age long before that.
230 whrs per mile (from the outlet) is possible with a very efficient
car and Lead-Acid batteries. As I recall the charge efficiency on Lions
isn't as good as PbA (but then again most advanced batteries aren't), so
that might be a bit on the low side for an efficient Lion based car.
On Thu, 2003-05-29 at 11:40, Christopher Zach wrote:
> Let's both go for a drive. You in a 25mpg car, and me in my Prizm. Distance
> of 25 miles.
>
> ICE:
>
> Fuel used: 1 gallon
> Cost of fuel: $1.75 (today)
> Cost for drive: $1.75
>
> Prizm:
> Power use on a 25 mile drive: 25 amps at 300 volts. About 300 watt hours per
> mile.
> Power used: 7,500 watt hours
> (Let's assume I am using the MagneCharger:)
> Charge efficiency: .90
> Power used at outlet: 8.25 kw
>
> Cost of power: 8c/kw hr
> Cost to make 8.25 kw hr of power: 66 cents
>
> So it costs me less to drive the electric car than the ICE car. You could
> say the electic car is comparable to an auto that gets 66 miles per gallon
> when the price of gas is 1.75 and the price of electricity. Bump the gas
> price to 2 bucks a gallon, and the equiv "MPG" to compare would be 75mpg.
>
> Chris
>
>
>
>
>
>
>
> ----- Original Message -----
> From: "Eric Penne" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, May 29, 2003 1:27 PM
> Subject: Efficiency numbers
>
>
> > I've been doing some napkin calculations that I will eventually post to
> > the list and put up on a website.
> >
> > According to my calculations which are very basic and estimate a lot:
> > Gasoline car - 25 MPG city milage
> > Gasoline $1.50/gallon
> > Electricity $0.08/kWh
> >
> > Rough guesstimate for LiIon pack of 6800 Cycles to 25% DOD.
> >
> > There's more info and calculations but I basically came out with a 230
> > Wh/mile figure for a BEV to have the same cost per mile as the above
> > mentioned 25MPG city vehicle.
> >
> > Is 230 Wh/mile in the city a reasonable figure?
> >
> > Related:
> > At 350 Wh/mile the same vehicle needed gasoline to jump to $2.71/gallon.
> > Is 350 Wh/mile resonable for city driving?
> >
> > Eric
> >
> >
>
--
EVDL
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It really isn't that bad.
Let's take my Henny for example. Now I don't know the watt hrs per mile on
it yet, so I'll guess at 300. If it's more or less, ok...
Here, I pay about $1.50 per gallon for gasoline. I also pay $.08 per kwh.
Ok, at 300 wh/mi, I can go 3.333 miles per kwh, or 3.33 miles per $.08 or
about 2.42 cents per mile. Not too bad.
Devide 2.42 into $1.50 and I get 61.98 or ~ 62 miles per gallon "gas
equivalent".
So at this point, it's cheaper. Now lets figure in the cost of batteries
and the like.
A full battery pack on this car will cost me ~600.00 (12 6v golf cart batts
at $50.00 each) (Yes there would be tax, but we'll skip that for now.).
Let's say I don't take too good care of the pack (or I put too much stress
on it) and it only lasts 2 years. That is $300.00 per year.
I drive 28 miles to work (round trip) every day. I do this for about 49
weeks out of the year, and 5 days per week. This comes out to 6860 miles
per year. This is assuming I never drive it on the weekends, and I never go
anywhere but back and forth to work. This is not reasonable, so I am going
to add about 1,200 more miles (this is arbitrary I know) for weekend and
running around driving. this rounds us out to an even 8,000 miles per year.
Ok, $300.00 devided by 8,000 is 3.75 cents per mile. This brings my total
cost per mile up to 6.17 cents per mile, or the equivalent of 24.3 miles per
gallon. So it looks like most gassers win.
But they don't.
First of all at 8,000 miles a per year, I will have to change my oil 2.66
times. I personally (I know this is not everyone else) use synthetic oil
and quality filters, so every oil change costs me $47.00 at the local jiffy
lube. So we need to add in $125.33 per year in oil changes for the gasser.
We also have to add in annual and semi annual costs like transmission fluid
(which the henny does not have/ use) radiator fluid, the occational radiator
flush, etc. With all these bills, I don't think it is unreasonable to add
$200.00 per year to the cost of the gasser. $200.00 devided by 8,000 miles
is an additional 2.5 cents per mile.
So if my battery pack only lasts for two years (and it jolly well better
last longer than that!!) I still come out better in pure cost than owning a
gasoline engine car that gets about 35 miles per gallon. (Approx, I'm going
to put all these numbers in a spreadsheet and see what I get.)
Now, add to that the convenience of the electric. I spend about 10 minutes
when I stop for gas. That's once a week (sometimes twice) vs the few
seconds I spend plugging in. The only maintenance I have is
checking/watering the batts, and that will take about 10 minutes +- about
once a month.
Add to it the lower emisisons, and it turns out to be better all round.
James
James F. Jarrett
Information Systems Associate
Charlotte Country Day School
(704)943-4562
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Bryan Avery
Sent: Thursday, May 29, 2003 3:54 PM
To: [EMAIL PROTECTED]
Subject: RE: Efficiency numbers
>
> So it costs me less to drive the electric car than the ICE car. You
could
> say the electic car is comparable to an auto that gets 66 miles per
gallon
> when the price of gas is 1.75 and the price of electricity. Bump the
gas
> price to 2 bucks a gallon, and the equiv "MPG" to compare would be
75mpg.
>
Yes, but when you average out the cost and life of the battery pack over
each mile driven(which I think is what Eric was getting at), the
cost/mile goes up quite a bit. I was trying to figure this out the
other day as well, and my conclusion was that my cost/mile with the
li-ions would be equivalent to driving a car that gets 25 mpg and paying
a bit over $2.00/gallon for the gas. This was figuring a 100,000 mile
life of the battery pack and a projected 240 wh/mile. I haven't seen
any real data about the number of cycles possible on the li-ions at low
DOD's, so the 100,000 mile figure was just a guess. Eric, how did you
come up with the 6800 cycle figure? If 6800 cycles is reasonable, then
that would mean about 200,000 miles for the pack and would actually make
it cheaper over the long-run than a 25 mpg gas car.
-Bryan Avery
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Or even a modified sinewave inverter. The problem with both of these
approaches is that they tend to be low voltage DC (12-24V).
Careful selection will get you an industrial drive that can run at pack
voltage.
On Thu, 2003-05-29 at 12:00, Ben Bennett wrote:
> Isn't there a way to use a computer battery back up for
> this? It seems to me it would every thing you'd need,
> battery input, 110 VAC output?
> --
> I'm not mooning you, just turning the other cheek
> Ben Bennett
> http://home.earthlink.net/~greyhawk200/
>
>
--
EVDL
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I wonder why driving automotive compressor from modern car (like
wrecked insight) from a motor of your choice (AC with inverter
as you suggested) is worse than running home window A/C compressor
by the same motor?
I can't see how efficiency of *latest* car compressors is that
much worse than that of generic GE window unit. Yes, they are labeled
high efficiency, so is labeled everything in a car - it is worthless
statement without true numbers attached). I doubt GE care about your
pocket book making A/C units more than GM making car's A/C units.
Please disproof me.
Victor
Lee Hart wrote:
>
> Alex Karahalios wrote:
> > Last quoted price I saw from Sanden regarding there electric compressor
> > and controller was around $3500.
>
> When a big company makes something special and unique, it's bound to be
> expensive. However, there is nothing all that special or unique about
> wanting to drive an electric motor from DC.
>
> What I would suggest is getting a good home air conditioner compressor.
> The cheapest way to get it is probably to buy the whole air conditioner,
> and just take out its compressor.
>
> Then, get an industrial variable-speed AC motor controller, the kind
> that allows you to vary the speed. We don't need to vary the speed; what
> we really want is the inverter that can accept a DC input voltage an
> generate normal AC to drive the compressor.
>
> It won't be the ultimate in efficiency, but it will be a heck of a lot
> better than running a DC motor to drive an automotive compressor.
> --
> 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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You're lucky Philippe. Getting Saft NiCads over here in the US is
somewhat cumbersome and expensive. Though every now and then someone
lucks out.
On Thu, 2003-05-29 at 12:34, Philippe Borges wrote:
> Saft NiCads are quasi indestructible, we use a bunch of them on our Scooler
> and go-kart since 5 years now, 0% failure and still strong at full amps.
> Note: we have seen all mistakes a customer can do:
> forget to fill the water in time, short them, wiring not perfectly tight, no
> connector cleaning...
>
> For the full amps, Saft data i have is near 700A during 10sec max if
> conditions are bad = when they pass 25°C and/or under 5V/module BUT until
> this limits you can stay at full amps !!! so on motor side you have plenty
> of power to burn rubber !
> What a pity cadmium is so crapy, Saft EV ni-cad are really (imho) the best
> batteries we can count on for a moment.
> though waiting for lithium or Ni-zinc...
> The next Scooler would be French Ni-zinc powered.
>
> Philippe
>
> Et si le pot d'échappement sortait au centre du volant ?
> quel carburant choisiriez-vous ?
> http://vehiculeselectriques.free.fr
>
> ----- Original Message -----
> From: "Jim Coate" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, May 29, 2003 4:29 AM
> Subject: Re: Batteries
>
>
> > 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'échappement 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
> >
>
--
EVDL
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