EV Digest 2823
Topics covered in this issue include:
1) Re: Efficiency numbers
by Chris Zach <[EMAIL PROTECTED]>
2) Re: air conditioning efficiency & motor requirements
by Seth <[EMAIL PROTECTED]>
3) Re: EV A/C Compressor
by Victor Tikhonov <[EMAIL PROTECTED]>
4) Re: Batteries (and caps too!)
by Seth <[EMAIL PROTECTED]>
5) Re: EV A/C Compressor
by Seth <[EMAIL PROTECTED]>
6) Re: Efficiency numbers
by [EMAIL PROTECTED]
7) Re: Efficiency numbers
by Peter VanDerWal <[EMAIL PROTECTED]>
8) Semiconductors (OT)
by Victor Tikhonov <[EMAIL PROTECTED]>
9) RE: Efficiency numbers
by Peter VanDerWal <[EMAIL PROTECTED]>
10) RE: EV A/C Compressor
by "Bryan Avery" <[EMAIL PROTECTED]>
11) RE: air conditioning efficiency & motor requirements
by "Bryan Avery" <[EMAIL PROTECTED]>
12) RE: EV A/C Compressor
by "Bryan Avery" <[EMAIL PROTECTED]>
13) Re: Batteries
by "1sclunn" <[EMAIL PROTECTED]>
14) Re: Speaking of niCads...
by Seth <[EMAIL PROTECTED]>
15) Re: Battery pack sizing questions
by "Ralph Merwin" <[EMAIL PROTECTED]>
16) Re: air conditioning efficiency & motor requirements
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Efficiency numbers
by Lee Hart <[EMAIL PROTECTED]>
18) Re: Todd DC/DC/ converter question
by Lee Hart <[EMAIL PROTECTED]>
19) Re: Lithium battery monitoring? ...
by Lee Hart <[EMAIL PROTECTED]>
20) Re: Todd DC/DC/ converter question
by "Joe Smalley" <[EMAIL PROTECTED]>
21) Re: Efficiency numbers
by Lee Hart <[EMAIL PROTECTED]>
22) Re: EV A/C Compressor
by Lee Hart <[EMAIL PROTECTED]>
23) RE: Todd DC/DC/ converter question
by Sharkey <[EMAIL PROTECTED]>
24) Re: Todd DC/DC/ converter question
by Peter VanDerWal <[EMAIL PROTECTED]>
25) Evercell cycling test reaches cycle 45
by "Joe Smalley" <[EMAIL PROTECTED]>
26) Re: Todd DC/DC/ converter question
by "Joe Smalley" <[EMAIL PROTECTED]>
27) RE: Todd DC/DC/ converter question
by Peter VanDerWal <[EMAIL PROTECTED]>
28) RE: Supercaps
by "Jorg Brown" <[EMAIL PROTECTED]>
29) Re: Todd DC/DC/ converter question
by "Joe Smalley" <[EMAIL PROTECTED]>
30) RE: Supercaps
by Peter VanDerWal <[EMAIL PROTECTED]>
--- Begin Message ---
Victor Tikhonov wrote:
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.
True, and I did recalc the pack. However in terms of overall ownership,
I believe the ICE engine still requires oil, exhaust, and other forms of
love that the EV doesn't.
And if you used a $1,000 pack and said the ICE needed a $500 repair
every two years (heck turning off an idiot light seems to cost $500)
then it might even out a bit closer.
How often do EV drivetrains fail?
Chris
--- End Message ---
--- Begin Message ---
I am pretty sure masterflux has a 300V unit with the bugs worked out.
One way to help is to insulate the car and tint the windows.
Seth
Christopher Zach wrote:
>
> 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/
> >
> >
> >
--
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
How one determines capacity needed (Btu/h)?
What is typical number for standard auto A/C in a car?
Victor
Rick Woodbury wrote:
>
> 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 ---
www.nesscap.com look at the 3500F cap with a 2.7V peak voltage.
5.4Wh/kg, although I wasn't thinking of these, I was thinking of
Nissan/GoreTex caps. That 5.4 doesn't take into account the .0005 ohm
(max) ESR.
Assuming a constant current discharge at the 1 minute rate figuring a
useable 9000 joules (of over 12,000) and an average voltage of 2.0V:
(start at 2.7, stop at ~1.35)
9000w*s *1min/60sec *1watt/volt-amp /2 volts= 75A
I^2R losses= 75*75*.0005 = 2.81W
2.81 watts *60 sec= 169 Joules
So they are (9000-169)/9000 efficient, or about 98% at the 1 minute rate.
8831Joules/3600sec *watt-sec/joule =2.45kWh
2.45kwh/0.65kg gives 3.78 kwh/kg
Not 6 but not 1 either. I think if you discharged to below half voltage
(1.35V) to something like 0.9V, you might be able to get in excess of
10,000 joules per capacitor.
And this isn't really fair because the mst likely use would be at
higher current, like a 20 second discharge where you would get at least
9X as much power loss. More like 1500 joules.
OTOH, these caps can have an ESR of more like .00035 ohms So figure on
~8000J in normal use, or 3.5ish kWh per kilogram.
If I did my math wrong, someone please correct me...
Seth
Lee Hart wrote:
>
> Seth wrote:
> > I think the caps are as high as 6 watt-hours per kilogram which puts
> > them at ~20% of lead acid.
>
> Where are the specs for a supercapacitor this good? I haven't seen
> anything anywhere close. Are they using specmanship to get it? For
> example, comparing watt-hours at the 1-minute rate. You can fully
> discharge a supercapacitor in 1 minute, but not a battery.
> --
> 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
--
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
9000Btu/h to 15000 btu/h is a good place to start. For an EV, aim low,
like 6000-9000 Btu/h Figure on burning at least 600-1000w to get it. If
I remember correctly, which I often don't.
Seth
Victor Tikhonov wrote:
>
> How one determines capacity needed (Btu/h)?
>
> What is typical number for standard auto A/C in a car?
>
> Victor
>
> Rick Woodbury wrote:
> >
> > 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
--
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
2700 Pound EV Beetle draws 50 amps at 72 volts for 25 mph.
3600 watts /25 miles = 144 watt hours per mile on flat level ground.
Increases to 80 amps at 35 mph or 5760 watts/35 miles = 165 watt hours
per mile.
12 Trojan T145s yield about two hours at 80 amps therefore 70 mile max
range at 35 mph on back roads without regen. Got 65 miles with 150
pound passenger during 1993 Tour de Sol over extreme mountainous New
England route after batteries broken in a few cycles.
12 US Battery 250HC are rated at 168 minutes at 75 amps and 78 pounds
each verse 72 pound Trojan T145's.
168/145=1.1586, 70 x 1.15 = 80.5 miles, probably closer to 75 miles in
New England.
12 x 72 = 864
12 x 78 = 936, but 936-864= 72 pound increase in weight to drag around.
72/2700 =2.67 percent increase seems reasonable for the extra 23 minutes
at 75 amps.
16 x 66 = 1056, but 1056-864 = 192 pounds above 2700 pound vehicle
96 volts / 72 volts = 1.333 times the voltage
125/145 = 86.2 percent time at 75 amps
1.333 x 86.2 percent = 1.149 times, but that extra 192 pounds means
192/2700 = 7.111 percent more energy needed per mile, so range is
decrease by atleast that amount or 1.149 x (1-.0711) = 1.0673 and that
extra 6.73 percent is probably eaten up in accelerating the extra 192
pounds and therefore the only real advantage to 96 volts of T125s is a
higher top speed in each gear.
I guess I will try the US250HC's this time.
Does anyone have cycle life data and cost numbers on US batteries such as
the US250 and US250HC ??
Menlo Park III,
Bill
On Thu, 29 May 2003 12:40:25 -0700 "Thomas Shay" <[EMAIL PROTECTED]>
writes:
> 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
> >
> >
>
>
________________________________________________________________
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--- End Message ---
--- Begin Message ---
> True, and I did recalc the pack. However in terms of overall ownership,
> I believe the ICE engine still requires oil, exhaust, and other forms of
> love that the EV doesn't.
No argument there, however many new ICEs need remarkably little
maintenance for the first 10 years or so. In fact many of them have
warranties that last that long.
>
> And if you used a $1,000 pack and said the ICE needed a $500 repair
> every two years (heck turning off an idiot light seems to cost $500)
> then it might even out a bit closer.
>
Umm, $1,000 will only buy you a 120V pack of 6V GC batteries... if you
can get a deal on them. Range will be approx 50 miles (max) If you
treat them well you will get 20,000 to 30,000 miles out of them.
$1,000 won't come close to buying you any kind of advanced batteries.
> How often do EV drivetrains fail?
>
Motors hardly ever fail unless they are abused or misused. Controllers,
on the other hand...
--- End Message ---
--- Begin Message ---
For those who's in electronics,
National sold some divisions to Fairchild link:
http://www.national.com/fairchild/part-74F.html
Victor
--- End Message ---
--- Begin Message ---
> 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.
>
Don't forget to calculate battery charge efficiency. PbA is about 90%,
the other technologies are even less efficient. If Lions end up
requiring active cooling, don't forget to calculate for that too.
--- End Message ---
--- Begin Message ---
I just checked with MasterFlux today and was directed to contact Glacier
Bay for purchasing info (since I'm not an OEM, just looking for
something for personal use). Glacier Bay is apparently still trying to
work out if/how they will handle and support sales to individuals such
as myself. Apparently it can be pretty easy to ruin the compressor if
the rest of the A/C system is not sized correctly to match the "mass
flow rate" of the masterflux compressor. I don't know that much about
A/C systems and vocabulary, so I don't really know where to begin for
calculating whether or not it would actually work in my vehicle. I did
get the impression, though, that by adjusting the speed of the
compressor it should be possible to match the output to a fairly wide
range of "mass flow rates." Anyone who has more knowledge of A/C
systems is welcome to give me some tips on how to figure this out. :-)
Unfortunately, Glacier Bay wants $1500 for the compressor & controller.
A lot less than Sanden's compressor, but still pretty expensive. I like
the sound of that $700-800 price a lot better. Rick, is this price only
for volume purchases as an OEM?
-Bryan Avery
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
> Behalf Of Rick Woodbury
> Sent: Thursday, May 29, 2003 4:57 PM
> To: EV List List
> Subject: EV A/C Compressor
>
> 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 ---
They advertise up to 700V input, but apparently have only built units
with power supplies up to 325V. I was told that the 325V unit has
overvoltage cutoff at 380V, so apparently could be fairly easily
reprogrammed (I assume at the factory if you requested it) to take a bit
higher voltage. They are supposed to be getting some larger power
supplies soon that would have no problem with the higher voltage, but it
sounds as if using the 325V version at a slightly higher voltage
(assuming this is doable) would provide more cooling capacity.
As for the specs, it sounds like the compressor is capable of providing
up to around 15000 BTUs of cooling while drawing about 1900W from the
batteries. With the larger power supply they were talking about, my
~340V would only push it to about 12000 BTUs of cooling. Apparently you
only get the peak output when running at the top of the voltage range
for the power supply.
-Bryan Avery
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
> Behalf Of Seth
> Sent: Thursday, May 29, 2003 5:20 PM
> To: [EMAIL PROTECTED]
> Subject: Re: air conditioning efficiency & motor requirements
>
> I am pretty sure masterflux has a 300V unit with the bugs worked out.
> One way to help is to insulate the car and tint the windows.
>
> Seth
>
> Christopher Zach wrote:
> >
> > 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/
> > >
> > >
> > >
>
> --
> [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
I was told that 20,000 BTU's was a reasonable estimate for the cooling
capacity of a typical automotive A/C system, but that automakers
typically overbuild their A/C systems. Most people on a hot day want
their car cold *right now* and don't want to wait a couple minutes for
the car to cool down. Of course, once it is cooled down, you don't need
nearly as much cooling to keep it that way, so a smaller system
essentially just means waiting a little longer for the initial
cool-down.
-Bryan Avery
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
> Behalf Of Victor Tikhonov
> Sent: Thursday, May 29, 2003 5:25 PM
> To: [EMAIL PROTECTED]
> Subject: Re: EV A/C Compressor
>
> How one determines capacity needed (Btu/h)?
>
> What is typical number for standard auto A/C in a car?
>
> Victor
>
> Rick Woodbury wrote:
> >
> > 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 ---
The batterie store here just got the 8v and I was thinking about them for my
next pack on the work truck as I will soon have a t rex to go in there. But
I am thinking twice now. Thanks
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: "EV" <[EMAIL PROTECTED]>
Sent: Wednesday, May 28, 2003 6:43 AM
Subject: Re: Batteries
> > Your probable right Lee and as you say "for your first EV" How about 15
8
> > volter's . Thats some where in between
>
> 8 volt batteries give you the worst of both worlds. Even LESS
> performance than 6 volt batteries and almost as much weight (950 lbs
> give or take).
>
> Coupled to even a 600 amp controller they will die quickly. To get any
> kind of life from these batteries maximum draw should be limited to less
> than 300 amps. After a year or two you'd be lucky to get 200 amps.
>
> Range when new will be about 35 miles, after a year or two it will be
> less than 20 miles (assuming he keeps the current down below 300 amps).
>
> Finally a set of 15 batteries will cost you as much or more as a set of
> 20 6v batts.
>
> You end up with a lead sled with glacial performance and batteries that
> die quickly even if you treat them right (two to three years max).
> Hook them up to a 600 amp controller and frequently bury your foot and
> you'll be lucky to get a year out of them.
>
> For an 8V performance example consider my truck.15 8 volt batteries that
> were somewhere near the middle of their life and a total weight of about
> 3200 lbs.
> 0-60 took about a minute and a half. This is while keeping pack voltage
> above 105 volts (about 250 amp draw)
>
--- End Message ---
--- Begin Message ---
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=26436&item=2416838406
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]
--- End Message ---
--- Begin Message ---
Ralph Merwin writes:
>
> The NiCads are sitting in a pile on the garage floor waiting either
> for someone to take them away
The NiCads have all been spoken for by a local EVer.
Ralph
--- End Message ---
--- Begin Message ---
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?
There are several reason.
First, home air conditioners MUST meet government efficiency standards.
Manufacturers must publish the power consumption and SEER efficiency
ratings, so buyers can compare them and buy the most efficient.
Therefore, high efficiency is a design requirement.
There are no efficiency standards or requirements for automotive air
conditioners. If it takes an extra horsepower due to low efficiency,
nobody is any the wiser.
Therefore, efficiency doesn't matter, and automobile manufacturers use
whatever compressor is the cheapest. There may be some exceptions, like
the Honda Insight or Toyota Prius, where they were trying hard to build
an efficient vehicle.
Second, auto air conditioner compressors are belt driven; the belt adds
losses. They have to work over a wide range of engine speeds, which
forces design compromises. The shaft requires rotating seals that add
friction and leaks. The large physical separation between condenser,
evaporator, and compressor requires longer hoses, which have a pressure
drop. All these factors lower efficiency.
Home air conditioner compressors are sealed, direct-coupled units. They
run at fixed speed for optimal efficiency. There are no rotating seals
or flexible hoses to leak. The compressor can be mounted anywhere, to
minimize plumbing.
PS: One other factor that is widely overlooked is insulation. You would
be nuts to air-condition a house that had no insulation and single-pane
windows, etc. The energy cost would be ruinous. But, cars have
negligible insulation. They are so bad that the typical car air
conditioner has enough cooling capacity for a small home. So, no matter
what system you use, at least add some insulation!
--
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 ---
James Jarrett wrote a pretty good summary of battery and elecricity cost
per mile for his Henny Kilowatt.
Eric Penne replied:
> 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?
The flooded golf cart batteries he used in his example are typically
rated for 700 cycles to 80% DOD. If he keeps it down to 50% DOD, they
will last 1000-2000 cycles.
I used $40 Sam's Club 6v batteries in my ComutaVan. I averaged about 50%
DOD, and in 7 years put about 20k miles and well over 1000 cycles on
them. One battery failed and was replaced after 4 years. The rest were
still at 50% capacity at 7 years old when I sold the vehicle.
> How much are you actually paying for electricity with your charger?
> I'm figuring 90% efficiency for the charge cycle with a PFC charger.
75-85% is closer to the range for chargers. Battery efficiency is also
in the 80-90% range. Taking the mid-point for each, about 68% of the
energy that comes in from the AC line comes out of the batteries to the
controller and motor.
--
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 ---
Peter VanDerWal wrote:
>
> 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.
You plug it in an try it :-)
You won't hurt it from trying to run an AC-only Todd on DC -- it just
won't work.
--
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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Chuck Hursch wrote:
>
> 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.
It's the power being dissipated in the filament that sets its
temperature, and thus its life. And power is most accurately predicted
from RMS voltage x RMS current.
--
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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The old ones had external extruded fins.
As I recall; the new ones were in a sheet metal case with a fan blowing
through it.
An example of external fins is
http://www.amplepower.com/products/chrg/img1.gif. The wires and cable in the
example are very similar to the old Todds. Three wire cable. Two terminal
screws and two box lugs all on the same end of the heat sink.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: "EV" <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 2:14 PM
Subject: Todd DC/DC/ converter question
> 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.
>
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>> However in terms of overall ownership, I believe the ICE engine
>> still requires oil, exhaust, and other forms of love that the EV
>> doesn't.
Peter VanDerWal wrote:
> No argument there, however many new ICEs need remarkably little
> maintenance for the first 10 years or so. In fact many of them
> have warranties that last that long.
But, ICEs are victims of strong wear-out mechanisms. An engine may go
100k or even 200k miles with only minor maintenance, but then it is just
plain worn out. The repair or replacement cost is enormous. The cost per
mile for an ICE needs to include its remaining value at the end of the
Except for the batteries, EVs basically don't have wear-out problems.
The motors can run indefinitely. Bearings, and maybe brushes are all
there is, and both can be easily replaced. Millions of miles on the same
motor are possible (and achieved, in things like electric trains and
buses).
Contactor controllers have contact wear-out, but the contacts are easily
replaceable. Electronic controllers don't wear out; they just work until
you exceed some rating and they "snap" (over-voltage, over-current,
over-temperature, or some other rating exceeded).
But... most hobby EVs have much higher failure rates than industrial EVs
or theory would predict. That's because many are experimental prototypes
that don't have all the bugs worked out, or built by naive builders who
under-sized and over-stressed the parts.
--
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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Bryan Avery wrote:
> I just checked with MasterFlux today... Apparently it can be pretty
> easy to ruin the compressor if the rest of the A/C system is not
> sized correctly to match the "mass flow rate" of the Masterflux
> compressor... Unfortunately, Glacier Bay wants $1500 for the
> compressor & controller. A lot less than Sanden's compressor, but
> still pretty expensive. I like the sound of that $700-800 price
> a lot better. Rick, is this price only for volume purchases as
> an OEM?
Rick (or anyone else): How about organizing a quantity purchase of (say)
10 systems? That should get the price down, and some knowledgeable
person could pick the rest of the parts to build workable system.
--
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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AFAIK, all of the old-style PS series Todds will run off of DC. In fact
they won't even care about the polarity unless you remove the input
rectifier and run the DC straight into the modules. (You gain efficiency by
eliminating the rectifier).
"Old" Todds are distinguished by the large, extruded aluminum case which is
roughly square in cross section and has one master module and one to four
slave modules. The "newer" Todds are lower profile and have the electronics
all mounted on one PC board (and the electronics is much more intricate
than the old units).
-S
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On Thu, 2003-05-29 at 20:41, Joe Smalley wrote:
> The old ones had external extruded fins.
> As I recall; the new ones were in a sheet metal case with a fan blowing
> through it.
Cool, the one I got looks similar to that except perhaps twice as long
(definitely external fins)
Here is the auction page:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3023392534
I guess nobody else bid on it because he called it a "Power Inverter"
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The MB100 being cycled has reached cycle 45 and is waffling above and below
80 AHr. I have not determined why the variation in capacity occurs on a
cycle by cycle basis. It may be time of day or temperature. I have not yet
overlaid the temperature plots to the capacity plots to check correlation.
Before I do, does anyone have any theories?
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
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Why did they change the design and then go out of business?
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Sharkey" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 8:51 PM
Subject: RE: Todd DC/DC/ converter question
> AFAIK, all of the old-style PS series Todds will run off of DC. In fact
> they won't even care about the polarity unless you remove the input
> rectifier and run the DC straight into the modules. (You gain efficiency
by
> eliminating the rectifier).
>
> "Old" Todds are distinguished by the large, extruded aluminum case which
is
> roughly square in cross section and has one master module and one to four
> slave modules. The "newer" Todds are lower profile and have the
electronics
> all mounted on one PC board (and the electronics is much more intricate
> than the old units).
>
> -S
>
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Next question, they made some low voltage units designed for EVs. Are
these required for 120V EVs (that sag to say 95V)?
If so is it possible to modify one for low voltage?
On Thu, 2003-05-29 at 20:51, Sharkey wrote:
> AFAIK, all of the old-style PS series Todds will run off of DC. In fact
> they won't even care about the polarity unless you remove the input
> rectifier and run the DC straight into the modules. (You gain efficiency by
> eliminating the rectifier).
>
> "Old" Todds are distinguished by the large, extruded aluminum case which is
> roughly square in cross section and has one master module and one to four
> slave modules. The "newer" Todds are lower profile and have the electronics
> all mounted on one PC board (and the electronics is much more intricate
> than the old units).
>
> -S
>
--
EVDL
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> Where are the specs for a supercapacitor this good?
> I haven't seen anything anywhere close.
After they sponsored the EV-1 with supercaps, I got a price quote from
Maxwell on these.
Your quote may vary; I priced them for my peculiar application which
would require a supercap to be able to handle voltages from 450V (regen)
down to 280V (minimum for controller)
They were available in 6 different containers:
PC2500, 2.5V each, 2500F, $65 each (Q 180) 725g 1.0mOhm 625A 8400J
http://www.maxwell.com/ultracapacitors/products/BCAP0010.html
NOTE! The PC2500 is cheap because they don't make them anymore!!
NOTE2 "cheap" is relative.
BCAP0010, 2.5V each, 2600F, $134 each (Q 180) 525g 0.7mOhm 625A 8400J
http://www.maxwell.com/ultracapacitors/products/BCAP0010.html
BMOD0117 Active, [EMAIL PROTECTED], $1011 each (Q 32) 6.5kg 4mOhm 600A 42kJ
BMOD0117 Passive,[EMAIL PROTECTED], $694 each (Q 32) 6kg 4mOhm 600A 42kJ
http://www.maxwell.com/ultracapacitors/products/BMOD0117.html
BMOD0115 Active, [EMAIL PROTECTED], $2982 each (Q 11) 16kg 10mOhm 600A 128kJ
BMOD0115 Passive,[EMAIL PROTECTED], $2082 each (Q 11) 15kg 10mOhm 600A 128kJ
http://www.maxwell.com/ultracapacitors/products/BMOD0115.html
By contrast, here's optima yellow top:
D750U 12V each, $110 each (Q 30) 750A 20.9kg 2.8mOhm [EMAIL PROTECTED]/2
And Hawker Genesis 12V42Ah:
G42EP 12V each, ???? each (Q ??) ???A 14.9kg ?.?mOhm [EMAIL PROTECTED]
For my purposes as a drag racer, I'd probably go with the cheapy PC2500s
or the Yellow Tops. That means either $3,080 for the YTs or $11,700 for
the PC2500s. Either would be capable of delivering the power I want for
about 10 seconds. 28 Yellow Tops would weigh about 1200 pounds, and the
supercaps would weigh only 274 pounds. If I got the newer model
supercap, they would weigh only 198 pounds, but that's not worth
doubling their price.
So, for the same peak power, cheap supercaps are 1/4 the weight, maybe
less, and 4 times as expensive, as high-power lead acid. (newer
supercaps are 1/6 the weight, and 8 times as expensive.)
For the same price, cheap supercaps are 1/16th the weight, 1/4 the peak
power, as high-power lead acid.
For the same weight, supercaps deliver 4x the power at 16x the price, as
high-power lead acid.
I mentioned these to Otmar, and he pointed out the internal resistance
difference. At full power, the supercaps are losing 1/8 to 1/4 of their
voltage to internal resistance. You can get around this by using twice
as many supercaps, which would cut the internal resistance to lead-acid
range.
- - -
The moral of the story
Many here have cited LiIon cells as a solution to long-range issues,
with plans to use LiIon and lead-acid to achieve both peak power and
peak energy. Depending on their voltage needs, I would suggest instead
that they should consider LiIon and supercaps to achieve their goal at
much less cost.
For drag racing purposes, it also looks like supercaps could provide
noticeable benefit, but at very high $ cost.
Hope this helps to get people thinking...
jorg
Note to self: EV Battery Glossary at
http://www.rtpnet.org/~teaa/battery.html
-----Original Message-----
From: Lee Hart [mailto:[EMAIL PROTECTED]
Sent: Thursday, May 29, 2003 11:59 AM
To: [EMAIL PROTECTED]
Subject: Re: Batteries
Seth wrote:
> I think the caps are as high as 6 watt-hours per kilogram which puts
> them at ~20% of lead acid.
Where are the specs for a supercapacitor this good? I haven't seen
anything anywhere close. Are they using specmanship to get it? For
example, comparing watt-hours at the 1-minute rate. You can fully
discharge a supercapacitor in 1 minute, but not a battery.
--
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 ---
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As I recall, the turns ratio on the transformer was about 43 to 4 so the
ratio was about 11 to 1. The unit will only put out about 10 volts if
operated on 110 VDC. You need at least 156 volts to get 15 volts out of
them. The transformer was not real low resistance, so the output voltage
sagged a couple volts under load so you needed a couple volts of overhead to
get full current out of them.
Yes, they can be rewound to operate on other voltages. I rewound mine to
operate from a 48 volt pack that pulls down to 36 volts under load. It does
that without the light dimming. See
http://www.austinev.org/evalbum/204.html.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: "EV" <[EMAIL PROTECTED]>
Sent: Thursday, May 29, 2003 10:05 PM
Subject: RE: Todd DC/DC/ converter question
> Next question, they made some low voltage units designed for EVs. Are
> these required for 120V EVs (that sag to say 95V)?
>
> If so is it possible to modify one for low voltage?
>
>
> On Thu, 2003-05-29 at 20:51, Sharkey wrote:
> > AFAIK, all of the old-style PS series Todds will run off of DC. In fact
> > they won't even care about the polarity unless you remove the input
> > rectifier and run the DC straight into the modules. (You gain efficiency
by
> > eliminating the rectifier).
> >
> > "Old" Todds are distinguished by the large, extruded aluminum case which
is
> > roughly square in cross section and has one master module and one to
four
> > slave modules. The "newer" Todds are lower profile and have the
electronics
> > all mounted on one PC board (and the electronics is much more intricate
> > than the old units).
> >
> > -S
> >
> --
> EVDL
>
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FWIW Optima YTs are not the best AGM battery for drag racing, far from it in fact.
For much less than the price of super caps you could buy Bolder TMF
cells (they still make those don't they?)
Bill Dube' was sponsored by them for a while (Killacycle 9.4 second 1/4
mile). Tiny PbA battery about the same diameter as a "C" cell and
perhaps 1.5 times as long. Put out about 300 watts for 10-15 seconds as
I recall.
The new SVR battery that EV parts is carrying is also better than YTs
(power to weight) 12V tested to 1500 peak amps, 900 amps for 10
seconds, weighs 11lbs 8oz and only costs $57.50
http://www.evparts.com/shopping/product_details.php?code=bt9520
These will give you roughly the same performance as YTs, weight 1/4 as
much and cost 1/2 as much (you might even be able to get a bulk
discount)
There are others out there.
> For my purposes as a drag racer, I'd probably go with the cheapy PC2500s
> or the Yellow Tops. That means either $3,080 for the YTs or $11,700 for
> the PC2500s. Either would be capable of delivering the power I want for
> about 10 seconds. 28 Yellow Tops would weigh about 1200 pounds, and the
> supercaps would weigh only 274 pounds. If I got the newer model
> supercap, they would weigh only 198 pounds, but that's not worth
> doubling their price.
>
> So, for the same peak power, cheap supercaps are 1/4 the weight, maybe
> less, and 4 times as expensive, as high-power lead acid. (newer
> supercaps are 1/6 the weight, and 8 times as expensive.)
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