EV Digest 4566
Topics covered in this issue include:
1) E-Meter & DC-DC Converter
by "August Johnson" <[EMAIL PROTECTED]>
2) Re: Battery de-sulfation
by Lee Hart <[EMAIL PROTECTED]>
3) Understanding Internal Resistance
by "Bill Dennis" <[EMAIL PROTECTED]>
4) Re: Thunder-Sky Straps
by "John G. Lussmyer" <[EMAIL PROTECTED]>
5) Re: Understanding Internal Resistance
by "John G. Lussmyer" <[EMAIL PROTECTED]>
6) RE: Understanding Internal Resistance
by "Ed Koffeman" <[EMAIL PROTECTED]>
7) 80v AC 3 phase EV Traction Motors and low voltage AC controllers
by "Peter Perkins" <[EMAIL PROTECTED]>
8) Re: Enthusiastic newby looking for good advice,comments, Stuff
by ROBERT RICE <[EMAIL PROTECTED]>
9) Re: What to do with excess regen power
by Lee Hart <[EMAIL PROTECTED]>
10) Re: Enthusiastic newby looking for good advice
by Lee Hart <[EMAIL PROTECTED]>
11) Re: EV-200 Resistor for 144v system
by Lee Hart <[EMAIL PROTECTED]>
12) Re: Field weakening setup
by Lee Hart <[EMAIL PROTECTED]>
13) Elec charge stations
by Rush <[EMAIL PROTECTED]>
14) Re: Elec charge stations
by Ricky Suiter <[EMAIL PROTECTED]>
15) Re: 80v AC 3 phase EV Traction Motors and low voltage AC controllers
by Rex Allison <[EMAIL PROTECTED]>
16) Re: Wayland Invitational Street Drags
by "Rich Rudman" <[EMAIL PROTECTED]>
17) RE: Wayland Invitational Street Drags
by "Myles Twete" <[EMAIL PROTECTED]>
18) RE: Understanding Internal Resistance
by "Bill Dennis" <[EMAIL PROTECTED]>
19) Re: Understanding Internal Resistance
by Danny Miller <[EMAIL PROTECTED]>
20) Re: Elec charge stations
by Brad E Jensen <[EMAIL PROTECTED]>
21) Re: EV-200 Resistor for 144v system
by Victor Tikhonov <[EMAIL PROTECTED]>
22) Re: Prius Conversion?
by ROBERT RICE <[EMAIL PROTECTED]>
23) Re: Understanding Internal Resistance
by Victor Tikhonov <[EMAIL PROTECTED]>
24) RE: John's GT-6
by "Roger Stockton" <[EMAIL PROTECTED]>
25) Re: Prius Conversion?
by Nick Austin <[EMAIL PROTECTED]>
26) Re: Prius Conversion?
by Ryan Stotts <[EMAIL PROTECTED]>
27) Re: Prius Conversion?
by Nick Austin <[EMAIL PROTECTED]>
28) Re: Charging in the heat
by "acid_lead" <[EMAIL PROTECTED]>
29) Re: new batteries, low specific gravities
by "Chuck Hursch" <[EMAIL PROTECTED]>
--- Begin Message ---
Hi,
I think I may have found a cheap, isolated DC-DC converter for use with the
E-Meter. It has 1KV isolation and accepts 9-18V input with 12V 250 mA
output. Cost is about $17 from www.newark.com.
http://www.newark.com/NewarkWebCommerce/newark/en_US/endecaSearch/partDetail
.jsp?SKU=95B9529&N=0
The data sheet says that the minimum output current is 50mA, but that it
will still work with less, just that the output ripple will increase.
I've ordered some and will let the list know how they work out.
August Johnson
--- End Message ---
--- Begin Message ---
Danny Miller wrote:
> OK, I looked at that battery. It's a 17ah SLA. The charger won't
> charge it... I had it on the charger at 13.8v for awhile and it's
> pulling like 200mA. Maybe 400ma @ 15v.
Try exactly what I said earlier. Put it on a higher-voltage charger (16v
to 24v) with a resistor or light bulb in series (to limit the current to
under 1 amp). Leave if for several days, or until the voltage stops
falling.
THEN try a load test, and your regular charger again.
--
The two most common elements in the universe are hydrogen and stupidity.
-- Harlan Ellison
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I'm trying to understand how internal resistance affects charging in TS
cells. For example, a 200Ah cell holds about 720Wh (200Ah * 3.6V). Let's
say I need to put 150Ah back into the cell during charging. I think I've
read that the 200Ah cell has a .001 Ohm internal resistance (someone correct
that figure if it's wrong, but I'll use it here for my question). If I
charge at 30A for 5 hours, then is the following correct:
P = I2R, so 30 * 30 * .001 = .9W
.9W * 5hours = 4.5Wh
Thus when charging at 30A, if I stop charging as soon as the cell reaches
4.25V, has the cell then been charged to 1 - (4.5Wh / 720Wh) = over 99% of
its capacity? Even with .005 Ohm internal resistance, the cell would be
charged to nearly 97% of its capacity. Seems too good to be true, so I fear
I'm missing something.
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
I think they would, though you would probably need 16 of them for
each block of cells.
Now, if you want to go cheaper, and have some extra space, you could
try a big hose clamp.
I haven't been able to find it in the online catalog, but last time I
was at harborfreight I picked up a hose clamp kit that was just 6' of
the strap, with 6 heads. You just cut the strap to the length you
need, and use one of the heads for each strap.
At 06:48 PM 8/9/2005, Ryan Stotts wrote:
On 7/5/05, Bill Dennis wrote:
> When I received my TS cells, the endplates came with long all-threads
> holding them together. But I've noticed that other people have received
> plates held together with metal straps. I think I'd like to switch to the
> straps. Are they just something that I can pick up at a hardware
store? Is
> there anything special I need to ask for?
Would these work?
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92515
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92516
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
At 07:09 AM 8/10/2005, Bill Dennis wrote:
that figure if it's wrong, but I'll use it here for my question). If I
charge at 30A for 5 hours, then is the following correct:
P = I2R, so 30 * 30 * .001 = .9W
.9W * 5hours = 4.5Wh
Thus when charging at 30A, if I stop charging as soon as the cell reaches
4.25V, has the cell then been charged to 1 - (4.5Wh / 720Wh) = over 99% of
You won't be ABLE to charge at 30A for 5 hours.
Long before the cell is full, the voltage will rise to 4.25v, and you
will need to continue charging at a lower current to keep the cell
from going over voltage.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
For Li cells, the percent of charge is almost perfectly related only to the
coulombs of electrons (amp-hours) coming and going during the charge and
discharge cycles.
The charge cutoff voltage represents the maximum voltage that closely
corresponds to having all the coulombs put back into the battery that it is
safe to stuff in there.
There is power wasted by the internal resistance, but you don't need to
figure that out to determine if it's charged, because the waste is a voltage
waste, not a current waste. You put in more voltage than gets used by the
battery, but all the current gets used to charge it.
Yes, they (Li cells) are really good at charge efficiency, in general.
Ed Koffeman
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Bill Dennis
> Sent: Wednesday, August 10, 2005 9:09 AM
> To: [email protected]
> Subject: Understanding Internal Resistance
>
> I'm trying to understand how internal resistance affects charging in TS
> cells. For example, a 200Ah cell holds about 720Wh (200Ah * 3.6V). Let's
> say I need to put 150Ah back into the cell during charging. I think I've
> read that the 200Ah cell has a .001 Ohm internal resistance (someone
> correct
> that figure if it's wrong, but I'll use it here for my question). If I
> charge at 30A for 5 hours, then is the following correct:
>
> P = I2R, so 30 * 30 * .001 = .9W
> .9W * 5hours = 4.5Wh
>
> Thus when charging at 30A, if I stop charging as soon as the cell reaches
> 4.25V, has the cell then been charged to 1 - (4.5Wh / 720Wh) = over 99% of
> its capacity? Even with .005 Ohm internal resistance, the cell would be
> charged to nearly 97% of its capacity. Seems too good to be true, so I
> fear
> I'm missing something.
>
> Thanks.
>
> Bill Dennis
--- End Message ---
--- Begin Message ---
Dear list members
There is now a plethora of AC 3phase low voltage controllers on market which
are just crying out to be put into a decent town EV. Low voltage = <100v
Power upto 20kw
But I'm struggling to find a motor in UK.
Any ideas on suppliers and or models?
Here some links to a couple of controllers.
http://www.electrofit-zapi.com/hfacinverters.htm
http://www.curtisinst.com/index.cfm?fuseaction=cProducts.dspProductCategory&;
catID=8
I have the manuals if list members want them.
Regards
--- End Message ---
--- Begin Message ---
Chip Sandy <[EMAIL PROTECTED]> wrote:
Hey all. Allow me to introduce myself.
My name is Chip Sandy.
Hi Chip an' All;
Welcome aboard! Nice to see another East Coaster heard from! NJ? Cool! Not
many guyz from Jersey heard from here. I always thought NJ was a good place for
EV's, relatively flat, too much traffic in most of it, so ya don't need
ludicris speeds(some times). I'm just down the road from you, CT. Drive a old
82 Rabbit conversion, 120 volts of T 105's a ADC 9 inch motor and DCP Rapter
controller. No fireball here 53 in the quarter at Power of DC, but I didn't
obviously, build it for smokin' takeoffs. As David Roden has pointed out on
here that you can sorta get used to a more leasurly pace. It IS nice to blast
up to 75 to get along on the freeway, I can, and do on the CT turnpike.
Well, don't hafta as much, as I'm retired from my OTHER electrics, Antrak
trains, and presently on my way West to Portland OR my yearly Pilgrimage, to
the Races at Woodburn and the Wayland Invitational at PIR in that same weakend.
Am somewhat there, stopped off at Netgain Headquarters in Illinois, borrowing
their computer to wade through a few hundred E mails. No, not the Rabbit, but
my faithful Toyota Prius, dropping off a few motors at Warfield Electric, for
rebuilds and picking them up on my back, saving big bux on shipping!Restocking
my dealer supply, adopting a few more for placement in loving homes. Lotsa cool
stuff from the good folks art Warfield, Netgain. Yes, Virginia there are 11, 13
and 15 inch motors for folks building their own trolley cars, the 15 inch frame
seems HUGH, like you see lying around a RR shop! Folks arent exactly beating
down the door for the bigger sizes, but they will be coming onstream
EVentually. Stay Tuned.But I said that I would ask.The n!
ew
offering , now is the Impulse 9 offering a slightly smaller footprint than the
9, about 2 inches shorter will bolt in to the 8 size wise, mounts, is a tad
lighter at 129 lbs, of course , slightly less power, but runs the same brush
rigging etc as the 9 inchers.for a space challanged mounting. tentative pricing
at a tad more than the 8 and less than a 9" Another offering for folks shopping
for motors.A beautiful sight to see at the factory, pallots of shiny new
-varnish- smell red motors awaiting loving homes. A visit to the factory is a
cool thing. the craftsmanship that goes into these things, the art like forms
the windings take as they are assembled together, the copper comms, the coils,
fitting together so elegantly. Your motor is so much more than a @#$% heavy
chunk of iron!
OK for you 11 incher fans;11.45 dia, wt about 229 lbs43.7 HP at 72 volts 453
amps 135 FT Lbs of torque 5500 RPM.but it could go pretty close to ten grand in
tests OK , how many would you like? Warfield needs a bigger dyno than 72 volts
for testing, they are working on that<g>!
Just some of the cool stuff I saw at Warfield'sJust wanted to comment on all
that. Will shove off this PM for Points west, Denver, SL city and Or. Gas seems
to run pretty much the same pricewise whereEVer you go. but still a hellova lot
cheaper than folks in Europe pay, so I can't really grouse. In that I CAN still
pull off a transcontinental, at the twist of a key, to me is a Modern Miricle,
when I feel like it and can carry stuff, within reason, EVen passengers.Maybe a
EV trip some day??Then I would need more time, like MONTHS! Being retired haz
it's bennies<g>! Imagine a EV convoy to woodburn, EVers joining in as I worked
my way west?Not just EV-1's have all the fun.Oh I know it's been done before,
for me the Great Clean Air Car Race of 1971, Boy! THAT dates me, Stevens Tech
team.EFP Fiberglas Postal Van 15 HP Baker motor, 120 volts verable pully drive,
like a snowmobile, setup. After we got GE to resolder(weld) our Comm to
armature coil leads back in,pit stop in Erie !
PA, the
van ran flawlessly, dispite blistering heat, most of the trip. It hummed along
doing from 40 to 90 miles a charge, depending on the hills. PERFECT mail
hauler, it COULDA bin, but the gone Postal Servive bombed out on any orders.
Politiks? Yeah! Sure they DO buy a hellova lot of gassers, then and now. A
Govt. agency then.
OK back to the Point. Chip, if ya want to see a working example of a modest
EV feel free to drive, fly or train up to CT, New Haven area to try the Rabbit.
It's a daily driver, french fries and loose change under the front seat, not
pretty, but functional vehicle, but wait til I get home in mid Sept fron the
Woodburn Jaunt. Hey If you're wanting to see REAL tire burning EV's Hop on Jet
Blue outta JFK they are having a "EVerybody Goes" Ticket sale, they DO go to
Portland. YEAH! Finally. Not too late to book, for Labor day weekend. You can
buy yur ticket on line, they DO go and arrive on time, a novel concept<g>!Check
them out. I'm a happy flyer(camper) So all you OTHER East Coasters, comeonout!
Hint hint! Lotsa crazy EV fun, meet the famous Zombie and Blue Meanie in
person, and all the other cool stuff lightin' them up at Woodburn!
Seeya There.
Bob
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--- Begin Message ---
Andre' Blanchard wrote:
> Are any of the companies building the hybrid cars working on
> some AI system so the car can learn your driving patterns?
> Like Monday-Friday you almost always go down this big hill,
> the computer can then use more energy then normal out of the
> battery before the hill so that there is room for the regen.
> All it should take is a GPS.
Yes, there's a lot that *could* be done with a smart enough computer.
However, most real-world computers are pretty stupid. With computers,
the gap between what it could do and what it actually does is pretty
large. :-)
My feeling is that the driver knows better than anyone where he is going
and what he is doing. So it would be better to provide controls for the
driver to manipulate that would allow better control.
This would no doubt require some extra controls and training. But people
are trainable (more so than cats or computers :-)
--
Humanity is acquiring all the right technology for all the wrong
reasons.
-- R. Buckminster Fuller
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Chip Sandy wrote:
> I don't necessarily need a 7-8 sec 0-60 time but I want good off
> the line acceleration.
This is where EVs have an advantage. Electric motors can deliver peak
torque right from a dead stop. So even a modest EV can deliver startling
off-the-line accelleration. This is a lot more impressive to the teenage
crowd than truly fast 0-60 mph times.
> a vast majority of NJ drivers are quite aggressive and tend to
> take advantage of slower cars. I am constantly cut off by people
> who drive faster cars than me simply because I just can't keep
> up.
This is an un-winable battle. Nothing is going to stop it except
converting a police car.
If you have a way to do it, it might be worthwhile to log one of your
daily commutes, so you can see just how fast you do drive and
accellerate. It could be as simple as a passenger with a watch and a
clipboard, writing down your speed every X seconds. You might be
surprised at how quickly (or slowly) you do drive.
You only have to build the EV to do what you actually do -- not what
your testosterone thinks you need to do. A car often "feels fast" just
because they rigged the gas pedal linkage so 0 to 1/2 throttle gives you
0 to 90% of available horsepower, and everything above that is mostly
noise.
--
Humanity is acquiring all the right technology for all the wrong
reasons.
-- R. Buckminster Fuller
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Lawrence Rhodes wrote:
> I just recieved my CzonkaIII contactor. To prevent arcing what size
> resistor is recommended across the contacts? I'll be running 144vdc.
> The spec. sheet doesn't mention anything.
I don't understand why you want a resistor across its contacts. Could
you explain a little more?
--
Humanity is acquiring all the right technology for all the wrong
reasons.
-- R. Buckminster Fuller
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Mark Hanson wrote:
> I was curious what is the best way to set up field weakening?
> Is diversion of 1/3rd the current acceptable or what is the rule
> of thumb for measuring and proper setup?
When they show motor curves with field weakening, they usually give data
at 1/2 field and 1/4 field. 1/2 field means with a resistor in parallel
that equals the field resistance. 1/4 field means the parallel resistor
is 1/3rd the field resistance.
Note that with such low resistances, you need to measure carefully and
use very good connections. Any switches or contactors you use can easily
have more resistance than the "resistors" you are trying to add.
> I wonder how inefficient field weakening is anyway and how much
> speed boost 10-25% maybe?
Motor efficiency per se doesn't drop much with field weakening. Since
normal field losses are only about 1%, doubling to 2% (1/2 field) or 4%
(1/4 field) doesn't take much away.
The speed increase can be quite dramatic. Or if the speed is held down,
the current increases substantially. You get a lot more horsepower, but
also make the motor run a lot hotter. Weak field also increases arcing,
so it should be used sparingly.
--
Humanity is acquiring all the right technology for all the wrong
reasons.
-- R. Buckminster Fuller
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hi all,
Just doing some site to site jumping I came across this url
http://www.eere.energy.gov/afdc/infrastructure/mapper.html. It maps your trip,
via Alternative fuels, from point to point.
Just for the fun of it I put in a elec route from Tucson to Wash DC for a trip
back to see family - "No route available" came up. I had a good laugh...
Rush
Tucson AZ
www.ironandwood.org
--- End Message ---
--- Begin Message ---
http://www.1opossum.com/evs/chargers/
Here's probably a better list of chargers for Arizona. A lot of them are
probably magnechargers if they're still there.
Later,
Rick <---- in Glendale btw
Rush <[EMAIL PROTECTED]> wrote:
Hi all,
Just doing some site to site jumping I came across this url
http://www.eere.energy.gov/afdc/infrastructure/mapper.html. It maps your trip,
via Alternative fuels, from point to point.
Just for the fun of it I put in a elec route from Tucson to Wash DC for a trip
back to see family - "No route available" came up. I had a good laugh...
Rush
Tucson AZ
www.ironandwood.org
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Do you know what the pricing is on these controllers?
--- Peter Perkins <[EMAIL PROTECTED]>
wrote:
> Dear list members
>
> There is now a plethora of AC 3phase low voltage
> controllers on market which
> are just crying out to be put into a decent town EV.
> Low voltage = <100v
> Power upto 20kw
>
> But I'm struggling to find a motor in UK.
>
> Any ideas on suppliers and or models?
>
> Here some links to a couple of controllers.
>
> http://www.electrofit-zapi.com/hfacinverters.htm
>
>
http://www.curtisinst.com/index.cfm?fuseaction=cProducts.dspProductCategory&;
> catID=8
>
>
> I have the manuals if list members want them.
>
> Regards
>
>
____________________________________________________
Start your day with Yahoo! - make it your home page
http://www.yahoo.com/r/hs
--- End Message ---
--- Begin Message ---
Madman and Goldie will certainly be there!!
This is the kind of fun that keep us old Fast Evers alive, Run it! play with
the Gas guys... Carry the Fast EV flag.. Just fast simple Racing...
They love us down there, and are trying to help get us power... We have a
couple of 120 VAC outlets, but we are bringing 8Kw and 10Kw generators. I
will have PFC 50s on each big Genset.
Charging should be in the 15 to 30 min span. Quite good enough for a hand
full of EVers in a hurry.
I am not sure If I will have 240 and a Zilla in Goldie.. But I will at least
have the old Yts and the Raptor on line.
At night... it's cooler, and there is not much a problem with Sunburn like
at Woodburn...Getting my Bains Braked out, is a Woodburn hazzard..
So... I will be there, hoping John can get as '05 in Madman's 100 club.
Street legal, real time slip....do it once...Got proof that's fine
with me....
Rich Rudman
Madman.
----- Original Message -----
From: "Roderick Wilde" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, August 09, 2005 10:47 AM
Subject: Wayland Invitational Street Drags
> NEDRA is proud to announce a new sanctioned event, The Wayland
Invitational
> Street Drags. Open to all street legal NEDRA drag racers. Come out and go
> head to head with the gas boys at Portland International Raceway (PIR)
> Friday September 2nd 2005. Gates open at 6 PM. Please note that there is a
> 90dBA sound limit for this event :-) This will be a first annual event.
You
> are all invited to join John in this first historical racing event either
as
> a spectator or participant. We have all heard John's exciting stories of
> racin the gas boys at PIR. Here is your chance to join in the fun. Track
> info at www.portlandraceway.com
>
> Roderick Wilde
> NEDRA President
>
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.338 / Virus Database: 267.10.5/67 - Release Date: 8/9/2005
>
--- End Message ---
--- Begin Message ---
I'll be there to support any way I can...
Indeed, John and his electric datsun draw a lot of interest, by the racers,
fans and the track announcer, Dave Bell, who's a good friend of mine. Dave
says that he really enjoys having the electric in the races to run against
the gas hogs...makes the races other than ordinary.
-Myles Twete, Portland
--- End Message ---
--- Begin Message ---
I think I understand what you're saying, John. If I've done a 150Ah
discharge to bring the cell down to 3V, then start charging at 30A, the
charger will initially start at somewhere above 3.03V, dropping .03V across
the internal resistance and putting the rest into the cell. As the SOC
increases, the charger keeps raising the voltage. Eventually (assuming the
internal resistance stays at .001 Ohm), the charger will be at 4.25V, at
which point there should be about 4.22V in the cell and .03V across the
internal resistance. What you're telling me is that this will take less
than 5 hours, so I haven't replaced the 150Ah yet. Without an E-meter, is
there any way to calculate the SOC of the cell at this point?
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John G. Lussmyer
Sent: Wednesday, August 10, 2005 7:23 AM
To: [email protected]
Subject: Re: Understanding Internal Resistance
At 07:09 AM 8/10/2005, Bill Dennis wrote:
>that figure if it's wrong, but I'll use it here for my question). If I
>charge at 30A for 5 hours, then is the following correct:
>
>P = I2R, so 30 * 30 * .001 = .9W
>.9W * 5hours = 4.5Wh
>
>Thus when charging at 30A, if I stop charging as soon as the cell reaches
>4.25V, has the cell then been charged to 1 - (4.5Wh / 720Wh) = over 99% of
You won't be ABLE to charge at 30A for 5 hours.
Long before the cell is full, the voltage will rise to 4.25v, and you
will need to continue charging at a lower current to keep the cell
from going over voltage.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
I don't think he's got the wrong idea. When a lead acid battery has
impedance problems such as those due to sulfation, the bulk charging
scheme may not work. The textbook bulk scheme is to apply a fixed
voltage and when the current falls below a certain level to drop out of
bulk. But if 1v is lost in impedance the current will drop below the
threshold at a very low charge state.
The mfg's procedure is still the best idea. Just be aware of extra
impedance you create through cables and interconnects. I've had many
troubles with my deep cycle battery under the hood not responding to the
multistage charger due to interconnect problems, mainly the terminals.
Danny
Ed Koffeman wrote:
For Li cells, the percent of charge is almost perfectly related only to the
coulombs of electrons (amp-hours) coming and going during the charge and
discharge cycles.
The charge cutoff voltage represents the maximum voltage that closely
corresponds to having all the coulombs put back into the battery that it is
safe to stuff in there.
There is power wasted by the internal resistance, but you don't need to
figure that out to determine if it's charged, because the waste is a voltage
waste, not a current waste. You put in more voltage than gets used by the
battery, but all the current gets used to charge it.
Yes, they (Li cells) are really good at charge efficiency, in general.
Ed Koffeman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Bill Dennis
Sent: Wednesday, August 10, 2005 9:09 AM
To: [email protected]
Subject: Understanding Internal Resistance
I'm trying to understand how internal resistance affects charging in TS
cells. For example, a 200Ah cell holds about 720Wh (200Ah * 3.6V). Let's
say I need to put 150Ah back into the cell during charging. I think I've
read that the 200Ah cell has a .001 Ohm internal resistance (someone
correct
that figure if it's wrong, but I'll use it here for my question). If I
charge at 30A for 5 hours, then is the following correct:
P = I2R, so 30 * 30 * .001 = .9W
.9W * 5hours = 4.5Wh
Thus when charging at 30A, if I stop charging as soon as the cell reaches
4.25V, has the cell then been charged to 1 - (4.5Wh / 720Wh) = over 99% of
its capacity? Even with .005 Ohm internal resistance, the cell would be
charged to nearly 97% of its capacity. Seems too good to be true, so I
fear
I'm missing something.
Thanks.
Bill Dennis
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--- Begin Message ---
If you think that is bad, I did a search for my entire State (Michigan) - no
station found.
Rush <[EMAIL PROTECTED]> wrote:Hi all,
Just doing some site to site jumping I came across this url
http://www.eere.energy.gov/afdc/infrastructure/mapper.html. It maps your trip,
via Alternative fuels, from point to point.
Just for the fun of it I put in a elec route from Tucson to Wash DC for a trip
back to see family - "No route available" came up. I had a good laugh...
Rush
Tucson AZ
www.ironandwood.org
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--- Begin Message ---
I think intent is to allow to pre-charge whatever is after contacts
thus reducing subsequent voltage difference and current spike
when contactor closes.
Lee Hart wrote:
Lawrence Rhodes wrote:
I just recieved my CzonkaIII contactor. To prevent arcing what size
resistor is recommended across the contacts? I'll be running 144vdc.
The spec. sheet doesn't mention anything.
I don't understand why you want a resistor across its contacts. Could
you explain a little more?
--
Victor
'91 ACRX - something different
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--- Begin Message ---
Nick Austin <[EMAIL PROTECTED]> wrote:
Hello,
I have a 2001 Prius that has had a total engine failure at 80,000 Miles. The
body is in good shape. Seems like an ideal EV conversion candidate!
Has anybody ever converted a Prius?
Hi NICK;
Gees! it DIED at 80k , they areSUPPOSED to last 100k Right?Like they have a
gaurantee, I THOUHT. I hava 01 Prius, too. I have thought of converting it
after it died, too. As they weigh, mine anyhow, 2500s as a working car. I
weighted it at my friendly junkyard. Pulling everything out and going Warp
motor standard tranny fron an Echo or a AC drive. Would be interesting.
Seeya
Bob
So now I'm trying to decide if I should have it fixed, or convert it to a
complete EV. If I do convert it and use it as a replacement for
its original mission, I'll need at least 120 mile range and overnight recharge.
Is this doable? I would like to spend less then $15000 on the conversion if
possible.
Or I could forget my pipe dream, sell this guy and buy a $2K gas car. But that
would be such a bummer. :(
What should I do?!
Thanks!
--- End Message ---
--- Begin Message ---
Bill,
You cannot separate internal resistance from the "ideal" cell as in
theory, claiming that 0.03V falls on the resistance but not on the
cell. The cell *is* that resistance. Separation is done only for
understanding and calculations. If the voltage on the terminals
is 4.25V it is not that it is 4.22 on the cell itself and 0.03V
drops internally on something else - it is not measurable separately.
Don't try to charge in certain Ah by timing CC phase - it won't work.
As John mentioned the voltage hits limit before (and if the battery is
cold - *long* before) the time is up.
You must use Ah counter as the rate of charge is not in general
predictable and the cell will accept charge at the rate depending on
current conditions.
Right way to do it is to charge manually to your desired voltage
limit (say, 4.2V), wait until current tapers down to 2A (@25'C)
disconnect the charger and reset Ah counter at this declared 100%SOC point.
From now on just use Ah counter and CC/CV charging (if you don't want
variable
current). If you hit 4.2V and no longer can push 30A in but charged
in only, say, 100Ah while previously took out 120Ah, you got to wait until
another 20Ah will get in at lower current, and this is something
you cannot time since the rate of current diminishing is not
always predictable well. No matter how accurately you try to estimate
it, the error will accumulate. With Ah counter it will not.
You will still need to recalibrate 100% SOC point once in a while,
(reset Ah counter) but it is safe to do only as seldom after every 100
cycles or so.
Victor
Bill Dennis wrote:
I think I understand what you're saying, John. If I've done a 150Ah
discharge to bring the cell down to 3V, then start charging at 30A, the
charger will initially start at somewhere above 3.03V, dropping .03V across
the internal resistance and putting the rest into the cell. As the SOC
increases, the charger keeps raising the voltage. Eventually (assuming the
internal resistance stays at .001 Ohm), the charger will be at 4.25V, at
which point there should be about 4.22V in the cell and .03V across the
internal resistance. What you're telling me is that this will take less
than 5 hours, so I haven't replaced the 150Ah yet. Without an E-meter, is
there any way to calculate the SOC of the cell at this point?
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John G. Lussmyer
Sent: Wednesday, August 10, 2005 7:23 AM
To: [email protected]
Subject: Re: Understanding Internal Resistance
At 07:09 AM 8/10/2005, Bill Dennis wrote:
that figure if it's wrong, but I'll use it here for my question). If I
charge at 30A for 5 hours, then is the following correct:
P = I2R, so 30 * 30 * .001 = .9W
.9W * 5hours = 4.5Wh
Thus when charging at 30A, if I stop charging as soon as the cell reaches
4.25V, has the cell then been charged to 1 - (4.5Wh / 720Wh) = over 99% of
You won't be ABLE to charge at 30A for 5 hours.
Long before the cell is full, the voltage will rise to 4.25v, and you
will need to continue charging at a lower current to keep the cell
from going over voltage.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
John Westlund [mailto:[EMAIL PROTECTED] wrote:
> Four 8'' motors? It was probably sucking a steady 1,200 or
> so amps from the battery pack(assuming it was a string of 28
> Optimas) the entire time accelerating up to that speed!
> Ouch. That'll cut range a bit.
Remember that it takes a certain amount of mechanical power to
accelerate the vehicle (or to maintain a given speed) regardless of the
type or number of motors. Assuming the pack sags to about 7V/battery,
your 1200A WAG corresponds to about 314HP from the battery. Dividing
this power across 4 motors means that each motor is operated at a lower
current, and is therefore more efficient, than if fewer motors were
used. This means that if only one or two motors had been used, then
even more battery HP would be required to develop the same mechanical HP
that the 4 motor setup did (i.e. the range would likely be worse with
fewer motors if the same performance level was to be maintained). This
assumes that the fewer motors could survive being operated at the
required point for the required duration... the other benefit of using
multiple motors is that the heat is spread out over 4x the brush and
comm area.
> I've tried to find more information on this car but have
> been unsucessful.
I know I have seen a photo of the car accompanying an article about it,
but can find neither online at the moment. Perhaps Rod Wilde can
provide more info or point interested people to the appropriate place?
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
>
> Nick Austin <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I have a 2001 Prius that has had a total engine failure at 80,000 Miles. The
> body is in good shape. Seems like an ideal EV conversion candidate!
>
> Has anybody ever converted a Prius?
On Wed, Aug 10, 2005 at 11:13:59AM -0700, ROBERT RICE wrote:
>
> Hi NICK;
>
> Gees! it DIED at 80k , they are SUPPOSED to last 100k Right?L ike they have
> a gaurantee, I THOUHT.
The 100K warranty for the Prius applies to the EV components, which are
working perfectly in my car. The engine is covered by a 45K warranty by
default. You can buy an extended warranty for 100K bumper to bumper coverage.
I thought that Toyota's really lasted, and was excited to own a car I though
would outlive my Jeep, and Caravan. My Jeep is now at 285,000 miles and the
Caravan was sold with 140,000 miles on it. So sad to see a Toyota die so much
younger then any other car I've had in my fleet. Oh well.
Thanks!
--- End Message ---
--- Begin Message ---
Nick Austin wrote:
> I have a 2001 Prius that has had a total engine failure at 80,000 Miles.
What exactly happened to it? Did it drop a valve or did the timing belt fail?
--- End Message ---
--- Begin Message ---
On Wed, Aug 10, 2005 at 03:25:26PM -0500, Ryan Stotts wrote:
> Nick Austin wrote:
>
> > I have a 2001 Prius that has had a total engine failure at 80,000 Miles.
>
> What exactly happened to it? Did it drop a valve or did the timing belt fail?
The number 2 cylinder has no compression, 1-4 have the rings dissolved. This
caused pitting at the top of the block. She now needs a new block, and the
number 2 piston needs to be machined down. The total cost for a new block,
the piston work, and labor is ~$5000.
My wife recently took it on a long trip across the US. On the return leg of
this trip the check engine light came on. She checked the engine oil and noted
that it was just above the add line, so she added a quart of oil. This put the
engine at about ~4.2 quarts of total oil. The Prius engine is extremely
sensitive to oil overfilling. It pushed the excess oil into the pistons and
into the intake manifold. The pressure of the oil on the pistons ate all the
rings. Or some such.
So Public Service Announcement: 3.7 quarts of oil in the Prius and no more :)
Thanks!
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--- Begin Message ---
The mfr info I've seen allows batt temp up to 50C (Optima, Hawker).
Are
your sensors 10C cooler than the core of the hottest battery? IF not,
you should be able to raise the limit somewhat. Some chargers can
ramp
back on power when asked, rather than completely shutting down. Ralph
Merwin is putting fans in his battery boxes that will come on if
things
heat up (tho their original purpose is hydrogen dispersion).
You may have to wait a long time for the lead to cool down...
especially if you have insulation for the winter.
-GT
--- In [EMAIL PROTECTED], Chris Zach <[EMAIL PROTECTED]> wrote:
> So a question for all the AGM people out there.
>
> I've set my MagneCharger to shut down charging when any of the pack
> sensors (8 thru the pack) read above 40C (110 degrees F). This is
all
> well and good, but what do you do if the temp outside is 100
degrees
or
> so and the car refuses to charge?
>
> Do you:
>
> 1) Raise the temp limits in the MC?
> 2) Charge slowly using the 2amp stupid charger and hope for not a
runaway?
> 3) Wait till it gets dark, cool, and charge then?
>
> What's the impact of charging in the heat? I'm sure this problem
must
> have come up on the EV1's and other people.
>
> Chris
--- End Message ---
--- Begin Message ---
I seem to be making some progress in getting these hydrometer
readings up a bit closer to where they should be.
Please see:
http://www.geocities.com/chursch/050626_hydrometer_readings.txt
http://www.geocities.com/chursch/050731_hydrometer_readings.txt
http://www.geocities.com/chursch/050807_hydrometer_readings.txt
The June 26 readings are where I started this thread. Hydro
readings were way low.
By the time July 31st rolled around, I had moved the constant
voltage set point up to 2.4V/cell as Roger had suggested, while
retaining the final constant I at 2A. I did add some water to
the cells after the June 26 hydro readings, because the
electrolyte levels were so low from the factory; however, I
certainly did not fill them up to the meniscus level. The hydro
readings really had not changed by the time July 31 rolled
around.
So on Aug. 6 I gave the pack a ~2hr equalization charge at 6A,
using the final I setting on the Zivan. The voltage basically
didn't go up any further after about an hour, to 2.69V/cell.
Waited ~24hr, and then took the readings given in the Aug 7 file
above. Yes, the hydro readings certainly are better now, so I
was probably undercharging before. One thing I can't fit into
the battery puzzle though, is why the standing voltages have
dropped so significantly? I understand 6.30V is a fully charged
6V battery, an average one at that. These are still only 2-3
months old, and now I have the standing voltages more typical of
an older battery after this equalize charge. I would think the
standing voltages would be in the 6.40-6.50 range. Also, voltage
sag is a little greater going up my little "standard" hill fresh
from my carport, although that's hard to judge. So what's going
on?
I have now set my regular daily charge final I at ~4A, and will
take hydro readings towards the end of the month and see what
give.
Thanks,
Chuck
Chuck Hursch
Larkspur, CA
http://www.austinev.org/evalbum/339.html
http://www.geocities.com/chursch/bizcard.bmp
On July 01, 2005 3:13 PM, Chuck Hursch wrote:
> Roger Stockton wrote:
> > Chuck Hursch [mailto:[EMAIL PROTECTED] wrote:
> >
> > > Anyways, I was rather surprised at how low the specific
> > > gravity readings were. Temperature (62-64 degF), the
> > > readings ranged from 1226 to 1261 (the table should be
posted
> > > at
>
http://www.geocities.com/chursch/050626_hydrometer_readings.txt).
> > > I usually run readings at 1270-1290, so I'm a little
> > > surprised, especially given the way the pack otherwise was
> behaving.
> >
> > Are your 1226-1261 readings before or after temperature
> compensation is
> > applied to them?
>
> Those are temperature-compensated readings. At that
temperature,
> it is only about 4 or 5 points.
> >
> > The temperature compensated values should certainly be over
> 1275 if you
> > are fully charging the batteries.
>
> I would think so. Somehow not all the lead sulfate is getting
> converted back.
> >
> > > My usual runs are 10-20 miles, usually closer to 10. My
> > > charging is done with a Zivan K2 120V charger, IUI with
bulk
> > > charge (the first I) at ~11A, the U is about
7.05V/6Vbattery,
> > > and the last I is at 2A.
> >
> > 7.05V/6V battery is a quite low 2.35V/cell. For an algorithm
> with a
> > timed constant current finish, such as you describe, you
would
> normally
> > charge to at least 2.4V/cell (and USBMC recommends
2.583V/cell
> for their
> > particular chemistry).
>
> Ok, I'll try turning it up to 2.4V/cell this weekend and see if
> that improves the hydrometer readings by the next battery
> maintenance session, which I usually do towards the end of the
> month, so late July. I'm leery of 2.583V/cell since I've seen
> and heard of a lot of cases where the batteries get hot or the
> pack unbalanced, and then the charger decides to keep on
charging
> the batteries right on into thermal runaway. I do have a
thermal
> probe for the Zivan, but the best I can do the way things are
now
> is tape the probe to the side of the rear pack's polypro case.
>
> So the 2.4V/cell and 2.583V/cell numbers mentioned above are
> really the numbers to be reached during bulk charge, at full
bulk
> charge rate? I think this is something that has always
confused
> me. Or are these numbers out there to then be woven into your
> own particular style of battery charging - still seems like a
> black art to me...
> >
> > 2A is a reasonable finish rate (for newish, helathy
batteries),
> and a
> > reasonable criteria for terminating the constant voltage (U)
> phase,
> > however, with such a low voltage the current may drop to this
> level
> > before your battery is fully charged, and then the fixed
> duration finish
> > phase may be unable to provide the amount of overcharge the
> battery
> > needs. Your finish phase can only provide 6Ah of additional
> charge.
>
> Lee Hart posted a list of specific gravities and percent
charged.
> I attempted to find that, but I was unsuccessful - must have
been
> using the wrong search string or looking in the wrong place in
my
> EVDL email folders. But anyways, 1226 is probably not more
than
> 80% charged up.
> >
> > > I've seen the batteries at 7.7V/6Vbattery during
> > > this final I, and my nose is telling me that things are
> > > gassing heavily.
> >
> > This is a good sign, as 7.7V/battery is 2.57V/cell, which is
> *almost* up
> > to USBMC's recommended charge voltage. However, it isn't
quite
> there
> > and the batteries may not be remaining at or above this level
> long
> > enough for the s.g. to come up fully.
> >
> > > Oh, also after the water fill, I decided to give the pack a
> > > 2-hr equalization charge @ 8A on the variac. Get things
> > > churning really good, and stinky at 8.15V/batt.
> >
> > Was the pack voltage still rising after 2hrs, or did you
> arbitrarily
> > decide to terminate the equalise charge there?
>
> The pack voltage was up to that 8.15V/batt within an hour and
> more or less stayed there for the duration, although it was
> starting to go down a bit towards the end. The temperature of
> the pack went from about 65-degF at the start to 75-degF at the
> end (I have a darkroom thermometer with circular face and a
stem
> that goes down between two of the batteries - the thermometer
is
> usually within a degree or two of the electrolyte temperature
> once things thermally stabilize, but in this case, with all
that
> energy going in, I suspect the plates were hotter by a few more
> degrees).
> >
> > You probably don't need to use quite that high an equalise
> current, but
> > if you allow it to continue until the pack voltage quits
rising
> and then
> > measure the s.g. after letting the pack rest perhaps
12-24hrs,
> you
> > should certainly be seeing values nearer to the 1290 mark.
>
> Yes, I may try another 8A (or a bit less, like 6A) run, then
> measure sg after a day. I'm a bit leery now of 8A equalization
> charges, since after doing them for awhile twice a month, my
last
> pack, which was a set of Trojan T125, seemed to start dropping
> cells (low capacity, low sg). Trojan's recommended equalize
rate
> apparently is 4A, while US's is 8A (and I think I've even seen
> 11-12A implied, ie. C/20, from Nawaz, which would seem a
> sure-fire way to murder your batteries).
>
> Always appreciate the advice. Even after driving an EV for
> eleven years, I'm still learning battery basics, how to charge
> them and keep them alive. It's a fine art...
>
> Thanks,
> Chuck
>
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