EV Digest 2822
Topics covered in this issue include:
1) Speaking of niCads...
by Peter VanDerWal <[EMAIL PROTECTED]>
2) Re: Efficiency numbers
by Victor Tikhonov <[EMAIL PROTECTED]>
3) Re: Lithium battery monitoring
by Victor Tikhonov <[EMAIL PROTECTED]>
4) Todd DC/DC/ converter question
by Peter VanDerWal <[EMAIL PROTECTED]>
5) RE: Efficiency numbers
by "Eric Penne" <[EMAIL PROTECTED]>
6) Re: Fw: Curtis controllers cheap.
by Peter VanDerWal <[EMAIL PROTECTED]>
7) Re: Efficiency numbers
by Peter VanDerWal <[EMAIL PROTECTED]>
8) Re: Efficiency numbers
by "Eric Penne" <[EMAIL PROTECTED]>
9) Re: air conditioning efficiency & motor requirements
by Peter VanDerWal <[EMAIL PROTECTED]>
10) Re: Battery pack sizing questions
by "Ralph Merwin" <[EMAIL PROTECTED]>
11) Better efficiency numbers.
by "James Jarrett" <[EMAIL PROTECTED]>
12) RE: Efficiency numbers
by "James Jarrett" <[EMAIL PROTECTED]>
13) Re: Drive it to the Power of DC
by Bruce EVangel Parmenter <[EMAIL PROTECTED]>
14) Re: Curtis controllers cheap.
by "The Levine Family" <[EMAIL PROTECTED]>
15) Re: Lithium battery monitoring? ...
by "Chuck Hursch" <[EMAIL PROTECTED]>
16) Re: Better efficiency numbers.
by Lonnie Borntreger <[EMAIL PROTECTED]>
17) Re: Battery pack sizing questions
by "Ralph Merwin" <[EMAIL PROTECTED]>
18) EV A/C Compressor
by Rick Woodbury <[EMAIL PROTECTED]>
19) Re: Efficiency numbers
by Peter VanDerWal <[EMAIL PROTECTED]>
20) Re: Speaking of niCads...
by Seth <[EMAIL PROTECTED]>
21) Re: Batteries
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
--- Begin Message ---
Anybody know where I can get some NiCads cheap?
Either enough for my E-cycle or better yet enough for my truck?
--- End Message ---
--- Begin Message ---
This is misleading. Cost of driving EV 25 miles as one instance
is not the cost of *ownership* of an EV making 25 miles trips every
day. Include at least periodic battery replacements. Still EV may win,
but by close margin. We drive it not because it's cheaper.
Victor
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
> >
> >
--- End Message ---
--- Begin Message ---
>From $3 to less than $1 depending on quantity.
Victor
Zachary Zeliff wrote:
>
> Hi, I'm new here.
>
> One question.
>
> How much ($) 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*.
> >> http://join.msn.com/?page=features/featuredemail
> > 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 ---
How do I tell the difference between the older Todds that will run off
120vdc and the new ones that won't?
I just won one of the large Todds on Ebay (75 amp maybe?)
Sorry if this is a repost, but I didn't see the message I sent last
night show up on the list.
--- End Message ---
--- Begin Message ---
What is your DOD at the end of your trip? What is the life cycle rating
of your batteries at that DOD? I wonder if you'll get 500 cycles at that
DOD?
I haven't calculated in any flooded batteries yet because there are just
too many choices. Optima YT and LiIon from Thundersky were easy targets
for now.
How much are you actually paying for electricity with your charger? I'm
figuring 90% efficiency for the charge cycle with a PFC charger. I may be
way high with that efficiency but it looks good right now.
> 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
--- End Message ---
--- Begin Message ---
That's a good deal, especially if they will honor the 2 year warranty.
I think Golf tech only gives 6 months or 1 year (don't recall exactly).
On Thu, 2003-05-29 at 12:59, Lawrence Rhodes wrote:
> 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....
> >
> >
> > ----------------------------------------------------
> > This mailbox protected from junk email by Matador
> > from MailFrontier, Inc. http://info.mailfrontier.com
> >
> >
> >
>
--
EVDL
--- End Message ---
--- Begin Message ---
> 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.
The rule of thumb for PbA batteries is 60% of the 20 hr rating.
For Nicads is almost 100% of the five hour rating (nicads typically
rated at the 5 hr rate since it's roungly the same from 2 hours to 20
hours)
I haven't a clue for the others except that NiZinc is about 100% AH but
significantly less volts so less watthours.
--- End Message ---
--- Begin Message ---
Here is the complex part of the equation, the variables.
Variables:
DOD
Cycle life at DOD
Cost of battery pack
MPG of gasoline car
Charger efficiency
Cost of electricity
Cost of gasoline
Wh/mile of car
Driving style
Lots of things need to be addressed. I just haven't gotten to them all
yet but I will. :)
> 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
--- End Message ---
--- Begin Message ---
I believe that there is a law the regulates how efficient window AC has
to be. The is no such law about auto AC. High efficiency is a relative
term so a high efficiency auto AC could be much better than average auto
AC and still far less efficient than window AC (just a SWAG)
However, I'd bet that the AC unit from a Prius or Insight is VERY
efficient and probably a good way to go (again just a SWAG)
On Thu, 2003-05-29 at 13:50, Victor Tikhonov wrote:
> 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
>
--
EVDL
--- End Message ---
--- Begin Message ---
Victor Tikhonov writes:
>
> 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.
I did buy used replacements. I changed out the first three modules
that died and tried to reinitialize the pack. Two more modules died
in the process (9 amps for 15 hours). This led me to believe that
the whole pack was soon going to die, module by module.
Then I learned that my car's configuration was drawing too much current
for too long a time for the SAFTs, which, according to a Brusa engineer,
leads to "dramatically reduced lifetimes".
If I want to continue to use NiCads, I would need to change to larger
modules and add more of them to keep my peak current draw below the
SAFT 'continuous' rating.
Many other people report that NiCads are almost indestructible, which
is why I used them. I assume something about my configuration or use
patterns is wrong, and the theory of damaging them with excessive
currents is certainly a plausible explanation.
It would be interesting to hear others. I do have the option of
replacing the entire pack with another used pack, but unless I know why
my old pack died and can change something to fix the problem, it would
be pointless.
Ralph
--- End Message ---
--- Begin Message ---
Ok, I had to guess at and round off some of my numbers here, so it is not
the gospel, but I'ts pretty good. It looks like that IN MY CASE as long as
my batteries last more than about 18 months, I come out ahead of a gasser
financially. This is based on my electric, and the milage of my current
gasser. These are straight out of my Excel spreadsheet.
Miles Driven Per Year 8,000 8,000
8,000 8,000 8,000
Cost per Gallon of Gas 1.5 1.5
1.5 1.5 1.5
Cost per KW/H of Electricity 0.08 0.08
0.08 0.08 0.08
Cost per Oil Change 47 47
47 47 47
Cost of Batteries 600 600
600 600 600
Life of Batteries (years) 1 2
3 4 5
Gas Milage of Car 22 22
22 22 22
WH/mi of electric 300 300
300 300 300
Additional Gas Costs 100 100
100 100 100
Additional Elec. Costs 100 100
100 100 100
Gas Cost per mile 0.068181818
0.068181818 0.068181818 0.068181818
0.068181818
Oil Cost per mile 0.015666667
0.015666667 0.015666667 0.015666667
0.015666667
Misc per Mile 0.0125 0.0125 0.0125
0.0125 0.0125
Total Cost per Mile (gasoline) 0.096348485 0.096348485
0.096348485
0.096348485 0.096348485
Electricity Cost per Mile 0.024 0.024
0.024 0.024 0.024
Misc Cost per Mile 0.0125 0.0125 0.0125
0.0125 0.0125
Batteries Cost per Mile 0.075 0.0375
0.025 0.01875 0.015
Total Cost per Mile (electric) 0.1115 0.074 0.0615
0.05525 0.0515
Total Cost per Year (gasoline) $770.79 $770.79 $770.79
$770.79 $770.79
Total Cost per Year (electric) $892.00 $592.00 $492.00
$442.00 $412.00
Savings per Year (electric) -$121.21 $178.79
$278.79 $328.79 $358.79
Percentage Savings per year -15.73% 23.20% 36.17%
42.66% 46.55%
James F. Jarrett
Information Systems Associate
Charlotte Country Day School
(704)943-4562
--- End Message ---
--- Begin Message ---
Responses inserted.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Eric Penne
Sent: Thursday, May 29, 2003 5:05 PM
To: [EMAIL PROTECTED]
Subject: RE: Efficiency numbers
What is your DOD at the end of your trip? What is the life cycle rating
of your batteries at that DOD? I wonder if you'll get 500 cycles at that
DOD?
* It depends, if I get to charge at school (looking iffy) my DOD is always
going to be about 35%. Without charging, it will be about 70. Not good I
know. I was HOPING on charging.
I haven't calculated in any flooded batteries yet because there are just
too many choices. Optima YT and LiIon from Thundersky were easy targets
for now.
How much are you actually paying for electricity with your charger? I'm
figuring 90% efficiency for the charge cycle with a PFC charger. I may be
way high with that efficiency but it looks good right now.
* Ok, there you got me, I did not consider efficiency, I should have. I
guess that means my numbers will be off between 10 and 20 percent. still
not too bad tho.
> 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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--- Begin Message ---
Before reading the POST I thought the thread was a request
to have EV'rs drive to the East Coast EVent. For me, that
would be one long tow from Silicon Valley :-o
...
Chris, I can relate to your desire to do this. I can see a
budding charging and long run addiction as big as mine.
I want to address your run 'to' the EVent, and not the
portion of your 'race run'. It reads like you have the race
run figured out.
Before answering your questions, I would rent that genset
and test its ability to put out the power needed. I say that
as it has been my experience with gensets at EVents, that
they do not put out the power they state they are rated at.
With a non power factor corrected charger, I only got half
the power out to the pack.
Though your magnecharger has a high power factor correction
value, and needs 6 kw, I would get at least an 8 kw genset.
At this capability, I do not think we have to worry about
the high voltage spikes possible with cheap 1 kw gensets.
I would rent the genset, then measure the time needed to
recharge a fully depleted pack with the magnecharger. Then
if all goes well, add a hour to your plans.
I always add a good fudge factor of time to my long trips
(ie: 300+ mile round trips to Sacramento off public
charging). Its best to plan that you 'will' have surprises.
Its just part of the journey.
I offer my suggestions having had experience going on long
trips with a heavy non regen wet cell 132 VDC S-10 Blazer
EV, that has half your voltage efficiency (600 amp
controller that draws 300- battery amps max.). Your more
efficient EV should give you the fudge factor (buffer) to
let you succeed.
>Prizm EV range of 40+ miles @ 65 mph
-First time on a new run, do it at a lower speed, say 60
mph. After verifying your capacities, you can try going
65 mpg the next time.
>Wash DC highways have hills and dales, some Appalachian
mountain climbing. How much power should I budget for long
hills?
-Do a dry run with the ICE, recording the miles that are flat,
the miles that up&down. I found the up&down miles use 30%
more power: The climb 3x the power, the coast +2x the power
from the stored kinetic energy. Example: From Saratoga I
climb the first portion of the 6 miles up Hwy 9 to Skyline
(the peak of the mountain) at 30 mph in second gear drawing
200 amps, the last 4 miles is steep and I average 25 mph
to maintain my speed around corners and draw 300 amps
(wide open). At the top, I used 3 times the power to
go the distances as compared on flat. 6 miles would be
~12 ahrs on flat, but 36 ahrs at the peak. But the
way down is 6 miles without using power. Since I have
no regen, it is brakes before the corner, let them
cool, and repeat. At Saratoga it is now 36 ahrs to
have gone 12 miles or 30% more power used when
compared to flat roads.
>stop & recharge at Frederick MD (44 mi down)
-This is is a good idea (you recharge both the EV and
yourself), but the portions of up and down driving use 30%
more power. I would bring your breakfast encase you 'have
to' recharge on the side of the road, short of your goal.
>can charge to 80% in 2 hrs (32 miles back)
-Verify this using the genset before the trip. And add time
to your plans. It always pays off. With AGMs you can not
push your last 30% of charge like I can with wet cells.
You do can not allow electrolyte to boil off, and be
replaced like I can. It might be better to plan to run
in the window of charge that optimizes your charge time.
In my case, I charge to 80% at 100+ amps at 150 VDC
(which boils off some water at the end), disconnect and
run to the next charge point. AGM chargers clamp the
charge current down at a point that is much sooner than
with wet cells. Having said that, that isn't what they
do at nedra races. A little stream from the top of their
AGMs means they have warmed the batteries. But one has to
think they aren't looking to maximize the life of their
batteries, but get the maximum performance for the next
race (different strategies).
>Prizm does have regen.
- You regen will add range, but not all the power used
is regained.
>increase speed on down-hills and never try to increase
speed on uphills.
-I use this when driving Hwy 280 just to maintain a traffic
safe speed. I go 70 down hill, and 60 up hill. But I have
to use 30% power climbing than on flat.
>pick a current draw and try to stay there if possible.
-I use this method on flat with great success, but have to
increase my current draw to maintain the same speed when
the up & down roads. I have draw 100 amps on flat, but up
to 200 amps on up and down roads.
>Let the car slowly lose speed on the way up.
-This works well. Trying to accelerate on the uphill just
unnecessarily blows amps past the motor windings. It
ticks off the drivers that make love to your rear bumper,
but they would do that anyway. Just stay in the right
lane and ignore the flying eagles flipped at you when they
finally pass.
>maximizing battery capacity on long hill strategies?
-You plan to not drive like an ICE, and keep one current
draw is what I do. If you hammer the pack you waste power
as heat and keep a spent electrolyte near your plates. One
steady draw is best for a long run. You are not nedra drag
racing here.
>taking a pack down to 20%, then up to 80%, then down to
20%, then up to 80-90% a bad idea? Do batteries slip out of
equalization quickly.
-The pack will slip out of equalization. But not enough to
stop you from achieving your goal. example: on a trip to
Sacramento, I recharge several times before throughly
recharging overnight. One trip, I did not do a
finishing/balancing charge until I go home (300+ miles and
3 days later). Remember that your available capacity to
accelerate is reduced by 10% with each incomplete recharge.
Example, on the way back from Sacramento, after putting
back the miles used from Vacaville + 10% with a 1 hour 6kw
charge at Concord Sun Valley Mall, when I left and I was
climbing to my next San Ramon charging point, acceleration
was sluggish, but it did eventually wind up. If you do not
plan for this, it can get hairy when dancing in morning or
evening traffic.
...
Even though you have a lighter more efficient EV than mine,
but you have a lighter pack capacity of AGMs, I think on
your first trip, my statements (above) still apply.
I think you should do all the preparations I mentioned and
do the run. Then write it up for the List to read. There
are many who could then enjoy in your success and the
experience.
=====
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor & RE newswires
. (originator of the above ASCII art)
=====
__________________________________
Do you Yahoo!?
Yahoo! Calendar - Free online calendar with sync to Outlook(TM).
http://calendar.yahoo.com
--- End Message ---
--- Begin Message ---
> Found this on the net. Lawrence Rhodes....
> Is this a good deal? Anybody have something used at a better price??????
>
With a 2yr warrantee? That's a great price!
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--- Begin Message ---
Lee Hart wrote May 28, 2003 1:27 PM:
> John G. Lussmyer wrote:
> > homebrew load... Hmm, maybe just 10 or 20 standard 120v
lightbulbs
> > being run at 160v or so. Wonder how long they would last? :-)
>
> Not long! For normal (non halogen) bulbs, here is the
relationship
> between voltage and life:
>
> % of rated voltage 100% 110% 120% 130% 140%
> % of its rated life 100% 30% 10% 4% 1.5%
>
> You'd be better off wiring pairs of 120v bulbs in series, so
they could
> take up to 240v. They still draw about the same current at 80v
each as
> they do at 120v.
Is it the RMS (heating, 120V) AC voltage that makes the
difference in terms of life? Or would the peak voltage (~170V)
make a difference? That is higher than the flat 160VDC.
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
www.geocities.com/chursch/bizcard.bmp
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--- Begin Message ---
On Thu, 2003-05-29 at 16:29, James Jarrett wrote:
> Ok, I had to guess at and round off some of my numbers here, so it is not
> the gospel, but I'ts pretty good. It looks like that IN MY CASE as long as
> my batteries last more than about 18 months, I come out ahead of a gasser
> financially. This is based on my electric, and the milage of my current
> gasser. These are straight out of my Excel spreadsheet.
Could you post that spreadsheet?
Lonnie
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--- Begin Message ---
Seth writes:
>
> what are you doing with the used(up) nicads? Some of us NEV/boat guys
> might be interested in them...
Seth,
The NiCads are sitting in a pile on the garage floor waiting either
for someone to take them away or for me to get the time/energy to send
them to a recycling center.
There are 22 air-cooled modules: 17 are intact but in suspect condition,
one has a cracked case, three have holes in the sides and one is intact
but has a shorted cell. I'll give these away to anyone that will pick
them up from my garage.
There are also three water-cooled modules that I bought to replace some
of the dead modules. These are used but were never used in my car.
I'll sell these for what I paid for them - $200 each, buyer picks up at
my garage.
I can deliver these if it's not too far from Portland, Oregon.
Ralph
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--- Begin Message ---
I noticed some posts on A/C compressors. The best deal I know of for DC
drive high-efficiency compressors is from Masterflux. See
http://www.masterflux.com/
The compressor was developed by Glacier Bay and is manufactured by Tecumseh
in the Masterflux division. Their development kit is less expensive than a
Sanden and each additional compressor is only about $700-$800 including
variable speed controller. We are switching to this compressor for the
Tango.
Hope this helps.
Rick Woodbury Phone: (509) 624-0762
President, Commuter Cars Corporation Toll-free: (800) 468-0944
Doubling the capacity of freeways Fax: (509) 624-1466
Quadrupling the capacity of parking Cellular: (509) 979-1815
Zero to 60 in under 4 seconds
715 E. Sprague Ave., Suite 114 Email: [EMAIL PROTECTED]
Spokane, WA 99202 Web: http://www.commutercars.com
--- End Message ---
--- Begin Message ---
For a given EV you can eliminate many variables by measuring WHrs(from
the outlet) over a month or so and measuring miles driven over the same
time. This will give you average WHrs/mile (from the outlet, including
equalizing)
Now you don't have to worry about charger efficiency, battery
efficiency, etc. It's all included in the WHrs/mile
On Thu, 2003-05-29 at 14:11, Eric Penne wrote:
> Here is the complex part of the equation, the variables.
>
> Variables:
> DOD
> Cycle life at DOD
> Cost of battery pack
> MPG of gasoline car
> Charger efficiency
> Cost of electricity
> Cost of gasoline
> Wh/mile of car
> Driving style
>
> Lots of things need to be addressed. I just haven't gotten to them all
> yet but I will. :)
>
>
> > 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
>
--
EVDL
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--- Begin Message ---
sg photo has them, and they even have 18Ah cells. My 48V pack will weigh
~150lbs but it is a nominal 30Ah at 1C (even though I got 40Ah)
Seth
Peter VanDerWal wrote:
>
> Anybody know where I can get some NiCads cheap?
>
> Either enough for my E-cycle or better yet enough for my truck?
--
[EMAIL PROTECTED]
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--- Begin Message ---
On 29 May 2003 at 21:34, Philippe Borges wrote:
> Saft data i have is near 700A during 10sec max if
> conditions are bad = when they pass 25�C and/or under 5V/module ...
That would be for STM5-140s. The limit is 5C, or 136 * 5 = 680 amps.
For the STM5-100s that Ralph had, the limit is 500 amps. Each 5C "hit"
raises the internal temperature a little more; at some point you're going to
hit the ceiling. But when you have a moderately heavy vehicle and 600 amp
controller, and you have to climb some hills, what are you supposed to do if
it takes longer than 10 seconds -- get out and push?
I think heat is the problem here. Nicads ^love^ cold weather, but if you
see ambient over 35 deg C very often (95 deg F), and you expect to routinely
request more than 2C amps, you have to be more careful. I suspect that you
really should have aggressive cooling, and temperature management that
starts backing off the controller current limit when internal cell
temperature exceeds 40 deg C, maybe 50 at the most. Without automated
temp
management, you'll just have to watch the temperature carefully and
discipline your right foot.
Saft says in the manual that if internal temperature hits 60 deg C (140 deg
F), STOP NOW. And that's internal temperature; most means of measuring
the
temp will be external and will lag significantly.
Saft also suggest that, after use, you hold off charging until temperature
falls below 35 deg C. So when you come home and plug in the car, your
battery box fans need to start up right away, and your charger should
probably watch the temperature too.
The STM5-140s, or even better the STM5-180s, if you can find any, are
probably on safer ground. They're bigger and can sink more heat. But the
STM5-100s are definitely best suited to light vehicles. They are fine for
Solectria Forces and similar cars, which weigh under 2500lb and have 250
amp
max inverters. For larger or faster vehicles, using 2 parallel strings
might be an option, if you can find the space.
I suspect, but don't know for sure, that some of this sensitivity to heat is
an unintended consequence of the reduced-maintenence design in the newer
100s and 140s.
BTW, the heat issue isn't exclusive to Saft nicads. The Ovonics NiMH that
were fitted to the NiMH EV1s had even worse problems. GM actually used
the
car's aircon to cool the battery tunnel, and wouldn't lease the NiMH cars in
the hottest regions of the US. (Well, OK, they wouldn't lease them in
^most^ of the US, but you know what I mean.)
I believe I've heard something like this for the Nickel Zinc Evercells. And
I wouldn't be at all surprised if it turns out that the Thundersky Lithium
Ion blocks need careful thermal management for long life, too. Perhaps it's
unavoidable with batteries that have relatively high energy densities.
David Roden
Akron OH USA
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