EV Digest 2562
Topics covered in this issue include:
1) Re: Fun with EV's
by "damon henry" <[EMAIL PROTECTED]>
2) Re: Truck (im)possibility
by Seth <[EMAIL PROTECTED]>
3) Re: When NiCads go boom
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
4) Re: When NiCads go boom
by "Ralph Merwin" <[EMAIL PROTECTED]>
5) RE: When NiCads go boom
by "Edward Ang" <[EMAIL PROTECTED]>
6) Re: Dump charger with manners (was RE: 20 minute charge to 80%)
by Lee Hart <[EMAIL PROTECTED]>
7) Saw a vehicle a couple of days ago...
by [EMAIL PROTECTED]
8) Re: Dump charger with no manners
by Lee Hart <[EMAIL PROTECTED]>
9) Re: Accessory belts, was:Truck (im)possibility, Regen on ADCs.
by Lee Hart <[EMAIL PROTECTED]>
10) RE: Accessory belts, was:Truck (im)possibility, Regen on ADCs.
by "Andre Blanchard" <[EMAIL PROTECTED]>
11) RE: When NiCads go boom
by "Roger Stockton" <[EMAIL PROTECTED]>
12) RE: When NiCads go boom
by "Tom Hudson" <[EMAIL PROTECTED]>
13) Re: Controller and Charger needed
by Paul G <[EMAIL PROTECTED]>
14) Re: When NiCads go boom
by Victor Tikhonov <[EMAIL PROTECTED]>
15) Re: Truck (im)possibility
by Victor Tikhonov <[EMAIL PROTECTED]>
16) Re: F250 Truck with AC system - no problem.
by Victor Tikhonov <[EMAIL PROTECTED]>
17) Re: When NiCads go boom
by "Ralph Merwin" <[EMAIL PROTECTED]>
18) 48 Volt charger wanted...
by jon <[EMAIL PROTECTED]>
19) Re: When NiCads go boom
by "Ralph Merwin" <[EMAIL PROTECTED]>
20) Re: F250 Truck with AC system - no problem.
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: F250 Truck with AC system - no problem.
by Victor Tikhonov <[EMAIL PROTECTED]>
22) RE: F250 Truck with AC system - no problem.
by "Humphrey, Timothy" <[EMAIL PROTECTED]>
23) Re: F250 Truck with AC system - no problem.
by Jim Coate <[EMAIL PROTECTED]>
24) Re: Electric Renault Express Vans
by Jim Coate <[EMAIL PROTECTED]>
25) Re: F250 Truck with AC system - no problem.
by Victor Tikhonov <[EMAIL PROTECTED]>
26) Grade definition
by Victor Tikhonov <[EMAIL PROTECTED]>
27) EverCell Charger question and miscellany
by Joseph Vaughn-Perling <[EMAIL PROTECTED]>
28) OT. Trade the Excursion for an EV.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
29) Re: EverCell Charger question and miscellany
by Rich Rudman <[EMAIL PROTECTED]>
--- Begin Message ---
I got half way through you post and though maybe John W. had posted a
new story, looked through the e-mail and found nothing ;-( .So I came
and finished reading yours , trying to figure how I got short changed .
ahhhh what is PDX.
PDX is the airport code for Portland OR.
After the big flame war over John's comments about putting the engineers in
a cage he signed off from the list. Bob's story did not come from the list.
damon
_________________________________________________________________
STOP MORE SPAM with the new MSN 8 and get 2 months FREE*
http://join.msn.com/?page=features/junkmail
--- End Message ---
--- Begin Message ---
Bus drives can be heavy, yes, up to 1000lb for motor(s) and brackets, or
less than half that. Buses can weigh 22,000 lbs on up to 80,000. Varying
vehcle mass, as well as varying motor style (with or without liquid
cooling and/or multiple gears) can get you lots of different motor sizes
in EV buses.
The Cummins that is in the 2003 "heavy duty" trucks is ~1000 lbs. I bet
the transmission is an allison (or equivalent) of at least 330 lbs.
I don't know how much the diesel in the F250 weighs, but I bet it is at
least 700 lbs. I hear it is a rebadged small International V8. Probably
the same transmission or one of similar weight.
So you have the opportunity to save a bit of mass on the propulsion, and
use it (and more) on batteries. If you get in the 1000 Wh/mile
neighborhood, and I think you can with regen and a decent design, then
this starts to look like 56 6 volt golf cart batteries. About 3000lbs
heavier than stock, in VERY rough numbers. I have never used Trojan
T-145s, but they look like a nice place to start with a PFC-50 and a
336V nominal AC drive. If you can go with LRR tires, like a Michelin
medium duty truck uses (start looking at what UPS uses on their fleet),
you can pick up a bit of range there. Mileage matters in commercial
trucking enough to make LRR tires a feature. Imagine that.
I am not fully up to date on Victor's (very nice) simulations. I was
wondering if the reduction in power above base speed as shown on the
metric mind website shown here:
http://www.metricmind.com/line_art/efficiency.gif
was reflected in the power available for acceleration, as it looked like
the battery DC current stayed at ~280A above base speed. I am assuming
that the other motors perform similarly when run above base speed and
fall below peak power? Maybe I missed something?
Seth
John Lussmyer wrote:
>
> At 05:09 PM 1/21/2003 -0800, Paul G stated:
> >Buying a used electric Bus might be a way to get a deal on high power
> >drivetrain (either AC or DC).
>
> One question on that, aren't the motors in Electric Busses kinda HUGE and
> HEAVY?
>
> --
> John G. Lussmyer mailto:[EMAIL PROTECTED]
> Dragons soar and Tigers prowl while I dream....
> http://www.CasaDelGato.Com
--
vze3v25q@verizondotnet
--- End Message ---
--- Begin Message ---
Wow, what a mess. I've heard of one case in which a module just opened up
under heavy load, but it just quit working. It didn't fail anything like
this, as far as I know. How much current were you drawing when the meltdown
occurred?
Have you been following Saft's recommendations for percentage of overcharge
and periodic equalization?
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David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1970 GE Elec-trak E15 36vdc
1974 Avco New Idea rider 36vdc
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Thou shalt not send me any thing which says unto thee, "send this to all
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--- Begin Message ---
"David Roden (Akron OH USA)" writes:
>
> Wow, what a mess. I've heard of one case in which a module just opened up
> under heavy load, but it just quit working. It didn't fail anything like
> this, as far as I know. How much current were you drawing when the meltdown
> occurred?
Between 200 and 300 amps. I have to accelerate uphill to merge with traffic
on the freeway. On normal days I regularly see 400 amps on the E-Meter for
a short time.
> Have you been following Saft's recommendations for percentage of overcharge
> and periodic equalization?
Assuming that the Brusa's profile is correct, then yes. However, I've
been wodering if the charger is not really doing a full %15 overcharge.
During the bulk phase the Brusa claims it's putting out 19 amps, but the
E-Meter says more like 15.1. The pilot counter is driven by the E-Meter,
so the charger replaces the AH drawn, but for the overcharge phase I think
the charger just runs a timer for %15 of the time spent in the bulk phase,
even though the current is less (~3 amps) than the charger claims (5 amps).
Ralph
--- End Message ---
--- Begin Message ---
Clare mentioned that when she was working on the Th!nk City, she has seen
similar incident, and even fire, on flooded NiCads when the water level is
too low. I sure like to know the true cause of this because I am testing
some used flooded NiCads on my Paseo.
Please keep us posted.
Ed Ang
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>> Since your golf cart battery was only at 13.8v, you could
>> raise the current a little more; to maybe 30 amps before the
>> voltage hit 14.2v at -25ah on the E-meter. AGMs would be
>> higher yet, and 12v floodeds with a higher Peukert exponent
>> would be lower.
George Tylinski wrote:
> Does this mean that in the case above (floodeds), the dump charge
> current would/should not exceed about 30 amps, even with unlimited
> charging power available?
Not quite. It means that the battery itself limits the charging current,
regardless of how much power is available. If you keep the voltage under
the gassing threshold (about 2.37v per cell), then the battery
self-limits to a safe level. If you force the voltage higher, the
battery still limits the current, but now it will be furious gassing,
heating, and will eventually be destroyed.
For example, suppose you have a 220 amphour 6v flooded golf cart
battery. You deeply discharge it at low current. Now put it on a
constant-voltage power supply that delivers 2.37v x 3 cells = 7.11v at
up to 1000 amps. The charging current looks like this:
at the start: -220ah + (220a x 5min) = -202ah
at 5 minutes: -202ah + (202a x 5min) = -185ah
10 minutes: -185ah + (185a x 5min) = -169ah
15 minutes: -169ah + (169a x 5min) = -155ah
...
at 1 hour: -77ah 77a
2 hours: -27ah 27a
3 hours: -10ah 10a
4 hours: -3ah 3a
5 hours: -1ah 1a
The current starts at 220 amps (because the battery needs 220 amphours),
but falls off rapidly. You'll get to 80% SOC (44ah to go) in about 1.5
hours -- but it takes over 6 hours to reach full charge. A graph of
charging current and amphours to go looks sort of like this (view with
fixed width font):
amps, and amphours
|
250|
|\
200|
|
150| \
|
100|
| -
50|
| - _
0|_______________________________-_______._________
0 1 2 3 4 5 6 hours
Now, this is a bit oversimplified. In reality, the battery also needs
extra current to make up for charging inefficiency being less than 100%.
Also, the battery will heat up as a consequence of the high charging
curentt -- if the charger doesn't temperature compensate its constant
voltage, the current will be higher yet. And if the voltage is too high
for the battery's temperature, it can easily go into thermal runaway.
Things go wrong fast at high charging currents!
> Does that mean hundreds of amps is neither feasible nor desirable
> (for a modest A-hr capacity traction pack) even using AGMs?
No, it is quite feasible, Maybe even desirable; Hawker AGMs apparently
need at least some high current charging, and even floodeds seem to like
it to help keep the electrolyte mixed.
The danger is that you (usually) don't know what the per-cell voltage is
in a long series string. Most of them might be under 2.37v, but one is
over it. The total string voltage allows a high current to flow. The one
high cell can't accept that much current; it's voltage shoots way up,
over 3v, and it begins overheating and gassing furiously. It doesn't
take long to boil the electrolyte. And then things REALLY happen fast!
> Can the max useful charging current be calculated or estimated for a
> given pack, and what info on the pack is needed? For example, 16X
> Optima YT in series.
Yes, as shown above. It will be 2-3 times higher for an Optima because
it is an AGM and has a lower internal resistance. Your peak current
could easily be 150-200 amps.
But, you really don't have to worry about "limiting" this current with
your charger. Just worry about limiting the battery VOLTAGE, and the
current will take care of itself.
--
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 ---
Hi all
This is a take from ongoing discussion about good donor vehicles, and for
Leslie in Kiwiland, attractive vehicles.
Driving through town a couple of days ago, stopped for the lights, a few
car lengths back from the intersection.
Noticed a vehicle alongside (parked) that I didn't recognise. A larger,
very sporty looking wagon, but what was it? (swivels neck a bit more).
Plush interior, body kit with side skirts, alloy wheels, sloped rear
lift-up door. (swivel - light still red - swivels back) Something a little
odd about the back doors !
Bingo!!
It was a dual-cab ute under all that stuff. The only give-away was the
chopped-off back edge of the rear side doors. I'd been thinking BMW/ Merc
but it was a Nissan/Toyota/etc 2WD dual cab, with a back end like a wagon,
nice and tight to the back of the cab. Nice sports body kit.
Beep! (car behind) light is green, gotta go. Came back later but it was gone.
Musings - what a way to do a mid-to-long range EV, up market but with the
capacity to cope with the necessary battery size.
So someone, assume in Australia, makes a body kit or kits for a common 2WD
ute, to make it into a psudo sports wagon, possibly with a full fibreglass
body (weight saving!) since I couldn't see a gap between the body and rear.
I loke the concept, maybe for all the USAns on the list, someone maybe
doing a similar kit for S-10s?
Nice to dream a little, gotta get back to work now.
James Massey
Launceston, Tasmania, Australia.
--- End Message ---
--- Begin Message ---
Steve Clunn wrote:
> My EV friend Tom and I have been making a kind of dump charger using
> a buck converter set up... he wants to keep the frequency low, 2 KHz
> (less transistor stress) and I want to go high 15k (as to get as
> much inductance from the coil)...
That's the classic trade-off. BTW, the inductance doesn't change due to
frequency; it's just that lower frequency requires more inductance for
the same amount of filtering; thus the inductor has to be physically
bigger.
> I want to hook up current limiting (which is on the chip we're
> using LM3524) he say we will do it by hand (pot on duty cycle).
Again, it's just a designer's choice. Current limiting adds complexity,
but can save your silicon if something goes wrong.
> We are feeding this thing with rectified 240 and a big cap, and to
> my surprise it has been working (but the smoke keeps getting out).
The old joke is that you can tell how far along a high power converter
is by the size of the bucket of dead parts. :-)
> Then smoke comes pouring out of my Todd DC/DC converter. This wasn't
> fet smoke but thick heavy smoke. It didn't take long to figure out
> what happened (dc/dc converter was the only load on the charger).
> Now here is the funny thing. I hooked up the connector on the one
> battery that split the pack and the DC/DC converter still worked!
That's because the capacitor is there so it will work on AC. It isn't
strictly necessary with a DC input.
> Back to coils. I don't know how to ball park the size of the toroid
> or how many raps of wire but I am thinking we are way under size
> (3" o.d. and 20 turnss).
For a buck converter, you decide how much output current ripple you
want. For example, 10 amps +/-10%. This would mean the average current
is 10 amps, and is actually going from 9 to 11 amps.
Next, you pick your operating frequency. As mentioned above, a lower
frequency is easier on the transistor, higher is easier on the inductor.
For the sake of argument, let's say 2 KHz.
Now, the equation for the inductance needed is V = L x di/dt, where V is
your input voltage, L is your inductance i henries, di is the peak-peak
change in current in amps, and dt is the time in seconds for one cycle
at your switching frequency.
Current is going between 9a and 11a. Assume your input voltage is the
rectified and filtered 120vac, so V = 120vac x 1.4 = 168vdc. The time
for one cycle is 1 /2KHz = 0.0005 seconds. Rearrange the equation, and
solve for L:
L = V / (di/dt)
= 168vdc / (11a-9a)/0.0005sec
= 0.042 henries, or 42 millihenries
Note that this is just a starting point. The inductance needed changes
with your AC line voltage, output current, and operating frequency. The
inductance has to be large enough to handle your highest input voltage,
lowest output current, and lowest frequency.
> I have a scope but not sure what to look for, coil saturation?
That's the next problem. Inductors saturate above some current, and
their inductance goes away. Since there is an average DC current flowing
in the inductor, it has to have an air gap or it will saturate at a very
low current. If you are using a toroid, people usually use a mopermalloy
core because it has a built-in distributed gap. Other types of cores
will require a slot.
If your core saturates at high current, its inductance falls
drastically. Then your transistor's peak current shoots WAY up, and the
transistor is destroyed. This is why you should have current limiting;
to save the transistor in case the core saturates.
To tell if your inductor is saturating, look at the current flowing in
it. It normally rises and falls smoothly. If it saturates, it suddenly
starts rising much faster when the current exceeds the saturation
current. You usually put a shunt or current transformer in series to
measure current.
> Trying different coils I've noticed that on some the wire gets hot
> and on others the toroid gets hot.
If the core gets hot, it is saturating, or being driven at too high a
switching frequency. If the wire gets hot, it is from simple I^2R
heating.
> I've also read where over 500 watts they use a full bridge setup
> for DC/DC converters.
There are several reasons for this. One, a simple one-transistor buck
converter has a huge input current ripple (0 amps, full amps; 0 amps,
full amps). So you need a huge input filter capacitor. As the power goes
up, the size of the input filter capacitors gets unreasonable. A half or
full bridge has less ripple, so the capacitors are much smaller.
Another is that the single transistor has to switch the converter's full
power, voltage, and current. A half or full bridge splits the power up
between multiple transistors, so they operate at lower stress levels.
This lowers cost, and indirectly improves efficiency.
And, the more sophisticated circuits can do power factor correction,
which gets progressively more important as you go to higher power
levels.
--
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 ---
[EMAIL PROTECTED] wrote:
> My current motor (ex-industrial) has a hardened shaft -- drill? Tap?
> Not a chance.
I have bits that will drills a hole in hardened steel. For fun, I've
drilled holes in a file! They are a special cobalt carbide bits made in
Germany and distributed in the US by Rodman & Company.
Tapping is another matter. I don't know of any practical way to tap a
hole in hardened steel.
My motor is an Advanced DC L91 -- I don't think their shafts are
hardened. If it is, then my only hope would be to press-fit my pulley in
place, and then drill holes (with the above-mentioned bits) and pin it
in place.
> Another option if you're out of length-wise space would be to put
> a 'lay' shaft alongside the motor, with the clutch on the end of
> the lay shaft, stepped back from the end of the motor so you only
> need enough space for the pulley and belt. Off that lay shaft you
> can run anything else - Vac. pump or whatever, spaced as needed
> in the motor bay.
I don't understand this. Do you mean a shaft, with its own bearings,
parallel to the motor shaft and running right beside it, with a belt
driving it from the end of the motor? And then using another belt or
whatever to drive the actual accessory load devices?
--
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 ---
How hard are we talking, I do not think a motor shaft would ever be very
hard unless it was intended for a very specialized use. Breaking from shock
loads and all that.
Anyway here are some taps for use in steels to about 44 HRc.
http://www.mscdirect.com/PDF.process?pdf=302
They are designed to be used in a machine tool but, I have very carefully
used them by hand.
It is also possible to put threads in anything that can be cut on an EDM.
Another possibility would be to design some kind of collet or taper lock
type coupler and use it with and outboard bearing so that the coupler only
has to handle the torque loading and not the cantilevered or bending forces.
Andre' B. [EMAIL PROTECTED]
If something cannot be defined, it does not exist.
Isaac Newton
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
Behalf Of Lee Hart
Sent: Tuesday, January 28, 2003 11:37 AM
To: [EMAIL PROTECTED]
Subject: Re: Accessory belts, was:Truck (im)possibility, Regen on ADCs.
[EMAIL PROTECTED] wrote:
> My current motor (ex-industrial) has a hardened shaft -- drill? Tap?
> Not a chance.
I have bits that will drills a hole in hardened steel. For fun, I've
drilled holes in a file! They are a special cobalt carbide bits made in
Germany and distributed in the US by Rodman & Company.
Tapping is another matter. I don't know of any practical way to tap a
hole in hardened steel.
My motor is an Advanced DC L91 -- I don't think their shafts are
hardened. If it is, then my only hope would be to press-fit my pulley in
place, and then drill holes (with the above-mentioned bits) and pin it
in place.
> Another option if you're out of length-wise space would be to put
> a 'lay' shaft alongside the motor, with the clutch on the end of
> the lay shaft, stepped back from the end of the motor so you only
> need enough space for the pulley and belt. Off that lay shaft you
> can run anything else - Vac. pump or whatever, spaced as needed
> in the motor bay.
I don't understand this. Do you mean a shaft, with its own bearings,
parallel to the motor shaft and running right beside it, with a belt
driving it from the end of the motor? And then using another belt or
whatever to drive the actual accessory load devices?
--
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 ---
> -----Original Message-----
> From: Ralph Merwin [mailto:[EMAIL PROTECTED]]
> Sent: January 27, 2003 9:34 PM
> To: [EMAIL PROTECTED]
> Subject: Re: When NiCads go boom
> > Have you been following Saft's recommendations for percentage of
> > overcharge and periodic equalization?
>
> Assuming that the Brusa's profile is correct, then yes.
> However, I've been wodering if the charger is not really
> doing a full %15 overcharge. During the bulk phase the Brusa
> claims it's putting out 19 amps, but the E-Meter says more
> like 15.1. The pilot counter is driven by the E-Meter, so
> the charger replaces the AH drawn, but for the overcharge
> phase I think the charger just runs a timer for %15 of the
> time spent in the bulk phase, even though the current is less
> (~3 amps) than the charger claims (5 amps).
Hi Ralph,
One possible problem is the CEF your E-meter is set-up with; during
discharge, the E-meter tracks Ah removed accurately (i.e. -100Ah
indicated for every 100Ah removed), however, during charge/regen it
tracks actual Ah multiplied by the CEF. Since the E-meter only allows a
maximum CEF of 0.99 (i.e. the E-meter indicates 99Ah returned for every
100Ah put into the pack, at best). If your charging setup bases the
[over]charge on the E-meter's Ah tracking of charge returned to the pack
you will always be shortchanged.
If the Brusa does just run a timer for the overcharge phase, then that
could also shortchange you, however, I would be very surprised if the
Brusa isn't monitoring the actual output current during bulk and
overcharge and counting actual Ah returned (otherwise, it could not
possibly charge accurately if the charge rate had to be reduced due to
thermal limiting of the charger in high ambients, etc.).
The E-meter generally is quite trustworthy, but bear in mind that ~20A
is just 3.8% of the full output of the 500A shunt it is measuring with
and that the 3.9A difference between its reading and the Brusa's is just
0.78% of full-scale.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
> Photos are online at http://www.aracnet.com/~rmerwin/prizm/noBMS.html
Whoa! That's pretty nasty, Ralph. I'd really like to know what happened,
because it seems very suspicious to me that two modules would "kicksplode"
(as we say in our house) within mere seconds of each other like that. My
guess is that maybe the one that is cracked had cracked at some point,
leaking electrolyte, it then overheated and melted into the second one,
causing it to go bad. Make sense?
Hmm. You mentioned a third module that had also overheated and leaked. Was
it adjacent to the others?
Also curious about whether the crack runs to either terminal on the cracked
battery -- It doesn't look like it.
And are those air-cooled modules? I'm asking because I see the
liquid-cooling nipples on them, but no interconnects.
Please keep us posted on what you find out; I want to be sure to keep my
pack happy, and this makes me a bit nervous...
-Tom
Thomas Hudson
http://portdistrict5.org -- 5th District Aldermanic Website
http://portev.org -- Electric Vehicles, Solar Power & More
http://portgardenclub.org -- Port Washington Garden Club
http://portlightstation.org -- Light Station Restoration
--- End Message ---
--- Begin Message ---
Seth wrote:
I am back from my west coast tour, and I met up with a few EVers in the
greater Las Vegas area. I saw his car, and a few others. We stopped by a
shop that did some Curtiss controller hot-rodding. Richard Frurniss
might be able to get you the name, it was a lot of names to remember
that day.
I would be interested in that info as well. I would like to have the
squeal removed from a 1231C controller. Something was posted onlist a
while back about removing the squeal from a 1221C, but I already have
two 1221B controllers.
Neon
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--- Begin Message ---
Roger Stockton wrote:
>
> If the Brusa does just run a timer for the overcharge phase, then that
> could also shortchange you, however, I would be very surprised if the
> Brusa isn't monitoring the actual output current during bulk and
> overcharge and counting actual Ah returned (otherwise, it could not
> possibly charge accurately if the charge rate had to be reduced due to
> thermal limiting of the charger in high ambients, etc.).
Brusa charger tracks actual amps in and out of the battery, but if I
understand Ralph's setup correctly, emeter is used to track Ah out the
pack and the charger to track Ah in the pack it's not the same.
Brusa's counter has no control over e-meter and the two obviously
disagreed here.
Victor
--- End Message ---
--- Begin Message ---
Seth wrote:
>
>
> I am not fully up to date on Victor's (very nice) simulations. I was
> wondering if the reduction in power above base speed as shown on the
> metric mind website shown here:
>
> http://www.metricmind.com/line_art/efficiency.gif
>
> was reflected in the power available for acceleration, as it looked like
> the battery DC current stayed at ~280A above base speed. I am assuming
> that the other motors perform similarly when run above base speed and
> fall below peak power? Maybe I missed something?
>
> Seth
You're on track. Fall above base speed is due to the limit for
the battery current. If you allow no batt current limit (so the
current can raise with RPM to maintain constant power), you'll have
nice straight line. Under some conditions base speed is >10,000 so you
never see that decline. This may be confusing at first, but really
quite simple phenomena.
Victor
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--- Begin Message ---
Rod Hower wrote:
>
> Victor,
> I liked the flow diagram. What did you use to create it?
> Rod
Sorry, what flow diagram?
BTW, I checked the page, some plots do not load. I have no explanation,
they do from my other computer...
Victor
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--- Begin Message ---
Victor Tikhonov writes:
>
> Roger Stockton wrote:
> >
> > If the Brusa does just run a timer for the overcharge phase, then that
> > could also shortchange you, however, I would be very surprised if the
> > Brusa isn't monitoring the actual output current during bulk and
> > overcharge and counting actual Ah returned (otherwise, it could not
> > possibly charge accurately if the charge rate had to be reduced due to
> > thermal limiting of the charger in high ambients, etc.).
>
> Brusa charger tracks actual amps in and out of the battery, but if I
> understand Ralph's setup correctly, emeter is used to track Ah out the
> pack and the charger to track Ah in the pack it's not the same.
> Brusa's counter has no control over e-meter and the two obviously
> disagreed here.
Not quite. The Brusa tracks ampours out/in until the pilot counter reaches
zero, at which point it stops counting until the next discharge cycle. The
charger does keep track of the overcharge amphours to know when to run the
next equalization or maintenance cycle, but I believe this does not use the
'charge' input (4hz/amp) but rather it just calculates this based on the
assumed overcharge current of 5 amps and the time spent in the bulk phase.
My translator parses the E-Meter's serial data for the 'amps' value and
sign character. It then sets a timer to the proper frequency (4hz/amp)
and routes the timer output to the correct Brusa input (charge or discharge)
based on the E-Meter's sign character. The timer output gets updated each
time the E-Meter sends out a new packet (once per second).
Ralph
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--- Begin Message ---
I'm looking for a 48 Volt (for flooded lead-acid) charger. Does anyone
have one they want to sell? I need one big enough to charge 8 Trojan
T-125s.
Thanks!
Jon
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--- Begin Message ---
Tom Hudson writes:
>
> Whoa! That's pretty nasty, Ralph. I'd really like to know what happened,
> because it seems very suspicious to me that two modules would "kicksplode"
> (as we say in our house) within mere seconds of each other like that. My
> guess is that maybe the one that is cracked had cracked at some point,
> leaking electrolyte, it then overheated and melted into the second one,
> causing it to go bad. Make sense?
The hole between the two modules doesn't actualy go into the 'cratered'
module, and that cell on the cratered module appears to be intact. But
anyting's possible.
I updated my web page with the chronology of weird events and ignored
errors, and my theory as to what happened. The web page URL is
http://www.aracnet.com/~rmerwin/prizm/noBMS.html
> Hmm. You mentioned a third module that had also overheated and leaked. Was
> it adjacent to the others?
No, it was in one of the two front boxes. Made a fine mess.
> Also curious about whether the crack runs to either terminal on the cracked
> battery -- It doesn't look like it.
Nope. The split is on the end of the case.
> And are those air-cooled modules? I'm asking because I see the
> liquid-cooling nipples on them, but no interconnects.
The air cooled modules and the water cooled modules are the same, except
the water cooled cases have an extra plate on the long sides to form the
water channel. In the side-views on my web page you can see the verticle
ridges that form the channel once the outer plate is installed at the
factor.
> Please keep us posted on what you find out; I want to be sure to keep my
> pack happy, and this makes me a bit nervous...
Will do.
Ralph
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--- Begin Message ---
John, out of curiosity I did dual AC setup simulation last night.
Turn out to be a fun truck:
0-50 km/h (31 MPH) - under 5 seconds
0-80 km/h (50 MPH) - 7.4 seconds
0-120 km/h (70 MPH) - 17.5 seconds
0-160 km/h (100 MPH) - 38 seconds
Max speed - 180 km/h (112.5 MPH).
Gradeability it will handle (angle degrees, not US % grade):
On 1st gear - 41.71� (is it close to 100% US grade?)
On 2nd gear - 19.55�
On 3rd gear - 10.17�
On 4th gear - 5.966�
On 5th gear - 4.324�
Someone tell me please definition in the US of a road slope grade :
|\
| \
A| \C
| \
|----\
B
The car is on the slope C. Is the grade=(A/B)*100% or (A/C)*100%?
In other words is it vertical drop A div by the distance on the
odometer B or vertical drop A divided by the distance on the map C
(horizontal line) which obviously is less than distance on
the odometer. For steep slopes it makes big difference.
I never got a clear answer...
Victor
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--- Begin Message ---
Sorry, correction for my typo:
Victor Tikhonov wrote:
>
> |\
> | \
> A| \C
> | \
> |----\
> B
>
> The car is on the slope C. Is the grade=(A/B)*100% or (A/C)*100%?
> In other words is it vertical drop A div by the distance on the
odometer *C* or vertical drop A divided by the distance on the map *B*
^^^^^ ^^^^^
> (horizontal line) which obviously is less than distance on
> the odometer. For steep slopes it makes big difference.
> I never got a clear answer...
>
> Victor
--- End Message ---
--- Begin Message ---
http://www.howstuffworks.com/question380.htm
> -----Original Message-----
> From: Victor Tikhonov [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, January 28, 2003 6:27 PM
> To: [EMAIL PROTECTED]
> Subject: Re: F250 Truck with AC system - no problem.
>
>
> John, out of curiosity I did dual AC setup simulation last night.
> Turn out to be a fun truck:
>
> 0-50 km/h (31 MPH) - under 5 seconds
> 0-80 km/h (50 MPH) - 7.4 seconds
> 0-120 km/h (70 MPH) - 17.5 seconds
> 0-160 km/h (100 MPH) - 38 seconds
> Max speed - 180 km/h (112.5 MPH).
>
> Gradeability it will handle (angle degrees, not US % grade):
>
> On 1st gear - 41.71� (is it close to 100% US grade?)
> On 2nd gear - 19.55�
> On 3rd gear - 10.17�
> On 4th gear - 5.966�
> On 5th gear - 4.324�
>
>
> Someone tell me please definition in the US of a road slope grade :
>
>
> |\
> | \
> A| \C
> | \
> |----\
> B
>
> The car is on the slope C. Is the grade=(A/B)*100% or (A/C)*100%?
> In other words is it vertical drop A div by the distance on the
> odometer B or vertical drop A divided by the distance on the map C
> (horizontal line) which obviously is less than distance on
> the odometer. For steep slopes it makes big difference.
> I never got a clear answer...
>
> Victor
>
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
> I did dual AC setup simulation last night.
As in two controllers connected to one motor (electric magic) or two
controllers with two motors bolted together (mechanical magic)?
> Someone tell me please definition in the US of a road slope grade:
>
> |\
> | \
> A| \C
> | \
> |----\
> B
>
> The car is on the slope C. Is the grade=(A/B)*100% or (A/C)*100%?
The first version: (A/B)*100
or "rise over run"
_________
Jim Coate
1992 Chevy S10
1970's Elec-Trak
http://www.eeevee.com
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--- Begin Message ---
Peter VanDerWal wrote:
> Except that I believe the NiCads are leased. Purchasing the car just
> gets you the option to continue leasing the batteries.
The little information I found on the vans from 'Google' talked about
the lease program, but Phillippe is definitely selling them (Tradin'
Post), and Jens confirmed battery ownership.
Schacherl Jens wrote:
Range is at least 90 km even at -15� Celsius...
That is a nice advantage! (we've had a bit of a cold snap in the
northeast US for a couple of weeks now)
You also need the Renault service computer to start the maintenance
> charge for battery watering and resetting the Ah counters.
That would be something of a nuisance... and would add to the challenge
of bringing one of the trucks to the US where such service wouldn't exist.
please see my related post about this at
http://autos.groups.yahoo.com/group/think_ev/message/1991 .
This thread is rather depressing... sounds like other countries I had
thought were still behind EVs are going the same way as the US. Lee's
observation of how the EV interest goes in cycles must apply at a global
level. Sigh.
_________
Jim Coate
1992 Chevy S10
1970's Elec-Trak
http://www.eeevee.com
--- End Message ---
--- Begin Message ---
Jim Coate wrote:
>
> Victor Tikhonov wrote:
> > I did dual AC setup simulation last night.
>
> As in two controllers connected to one motor (electric magic) or two
> controllers with two motors bolted together (mechanical magic)?
>
Optimal would be neither. You use two inverters and two motors
independently directly driving both drive shafts of 4x4, as Cliff
Rassweiler does it (www.ProEv.com)
Only if you want to retain the gear box, you do mechanical magic thing.
Victor
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--- Begin Message ---
"Humphrey, Timothy" wrote:
>
> http://www.howstuffworks.com/question380.htm
>
Checked that. Beware they made the same typo I did initially, so
they claim B^2 = C^2 + A^2 which obviously is totally wrong.
|\
| \
A| \C
| \
|----\
B
Also the reasons they give for specifying grade rather
than angle, male little sense and for steep grades are
simply wrong as well (because of above error).
But let's not engage in another debate over units :-)
Victor
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--- Begin Message ---
Is there a charger on the market that will support the NiZn chemistry in
the EverCell batteries?
NiZn doesn't like trickle charging at all. It likes high energy dump
charging best.
I'm imagining a charger that can take 110/220 10 amps and up to 50 or so.
I know there are some folks using these batteries on this list, what type
of charger are you using? Any idea how well it is working to preserve
the battery life?
My EV is probably going to sit in the garage until I can get advanced
batteries into it since my commute is roughly doubling. 20 miles -> 40
miles each way. 108v of PbA 6v bats with 10k miles on them just won't
last on that daily commute.
I had to put gas in a car today for the first time in over a year. It
made me feel dirty.
I'm going to have to do some re-engineering. I sent my needs as a sort of
RFP to Ken Koch a month or two ago but I haven't had anything come back
from him yet. He's an alumni of my high school so I wanted to give him
the business first.
I'm expecting I'll have to do a fairly major upgrade: Batteries, and
charger for certain, maybe controller as well. Adding regen and a battery
management system might also be within my budget. I was getting ready to
bite the bullet and buy a RAV4 EV, but... (heavy sigh)
If anyone feels generous and wants to suggest some creative alternatives
my car's configuration is on the web site below:
--
____
__/o|__\~ ~ ~
`@ -----@`---(=
http://www.SoCalEV.com
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--- Begin Message ---
Not exactly EV. But you know where I'm going. Lawrence Rhodes.....
1.
SUPER-EFFICIENT CHEESEHEADS
Going green could save Wisconsin more than $225 million over the next
two years, according to a coalition of state environmental groups.
Yesterday, the groups released a "Green Budget" itemizing ways
Wisconsin could save money while protecting the environment. One of
the budget's simplest recommendations -- using more efficient
lighting and turning off unused electronic equipment in state office
buildings -- would save between $9.2 million and $18.4 million per
year, and far more if public schools followed suit. Purging the
state's car fleet of gas-guzzling vehicles like the Ford Excursion
would also save a chunk of money, according to the report. Other
suggestions ranged from eliminating tax breaks and exemptions for
polluters and the timber industry to axing pricey road-building
projects. The recommendations come as the state stares down a
two-year projected budget shortfall of $3.2 billion dollars.
straight to the source: Wisconsin State Journal, Ron Seely, 27 Jan 2003
<http://www.madison.com/wisconsinstatejournal/local/41484.php>
--- End Message ---
--- Begin Message ---
Joseph Vaughn-Perling wrote:
>
> Is there a charger on the market that will support the NiZn chemistry in
> the EverCell batteries?
Yes Mine comes close.
>
> NiZn doesn't like trickle charging at all. It likes high energy dump
> charging best.
>
False. This will kill them!!!
> I'm imagining a charger that can take 110/220 10 amps and up to 50 or so.
>
PFC50s do 50 amps input 120 to 240 all inclisive. At 108 I can hand you
75 amps of charge current from 240 and 208 VAC..
> I know there are some folks using these batteries on this list, what type
> of charger are you using? Any idea how well it is working to preserve
> the battery life?
>
If you are NOT real carfull you will kill your Evercells right quick.
> My EV is probably going to sit in the garage until I can get advanced
> batteries into it since my commute is roughly doubling. 20 miles -> 40
> miles each way. 108v of PbA 6v bats with 10k miles on them just won't
> last on that daily commute.
That's for sure
>
> I had to put gas in a car today for the first time in over a year. It
> made me feel dirty.
>
Yup!
> I'm going to have to do some re-engineering. I sent my needs as a sort of
> RFP to Ken Koch a month or two ago but I haven't had anything come back
> from him yet. He's an alumni of my high school so I wanted to give him
> the business first.
>
> I'm expecting I'll have to do a fairly major upgrade: Batteries, and
> charger for certain, maybe controller as well. Adding regen and a battery
> management system might also be within my budget. I was getting ready to
> bite the bullet and buy a RAV4 EV, but... (heavy sigh)
>
> If anyone feels generous and wants to suggest some creative alternatives
> my car's configuration is on the web site below:
>
> Yea forget the dump charging on Ni Zn. Forget amp draws of more than 250 for more
>than seconds.
Dial up a 240 volt 400 amp EV and then rethink Evercells.
Forget Regen... unless you want to go Sepex or AC induction.
--
> ____
> __/o|__\~ ~ ~
> `@ -----@`---(=
> http://www.SoCalEV.com
There is a lot of cycle data on my website regarding Evercells. Read it.
then tell me if you want to play this game. Right now us charger
builders are teaching Evercell how to charger thier own batteries.
Succes can be had, but it's still a R&D effort by all concerned.
I expect a ton of questions......
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
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