EV Digest 3247
Topics covered in this issue include:
1) Re: Politics Light
by Rich Rudman <[EMAIL PROTECTED]>
2) Re: Mike's electric adventure
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Filter Caps on battery chargers
by Lee Hart <[EMAIL PROTECTED]>
4) Re: Zivan NG1
by Lee Hart <[EMAIL PROTECTED]>
5) BEVs at the 2004 Tour de Sol
by M Bianchi <[EMAIL PROTECTED]>
6) Re: Cold and old. Was: Mike's electric adventure
by Michael Hoskinson <[EMAIL PROTECTED]>
7) Re: Mike's electric adventure
by Michael Hoskinson <[EMAIL PROTECTED]>
8) RE: ultracapacitors
by "Roger Stockton" <[EMAIL PROTECTED]>
9) Re: Mike's electric adventure
by "Joe Smalley" <[EMAIL PROTECTED]>
10) RE: Cold and old. Was: Mike's electric adventure
by "Roger Stockton" <[EMAIL PROTECTED]>
11) RE: Prius Conversion
by "Roger Stockton" <[EMAIL PROTECTED]>
12) LiOn Charging Temp (was: Prius Conversion)
by [EMAIL PROTECTED]
13) RE: Prius Conversion
by "Roger Stockton" <[EMAIL PROTECTED]>
14) RE: Prius Conversion
by "Roger Stockton" <[EMAIL PROTECTED]>
15) Re: OT: Diesel Question
by Martin Klingensmith <[EMAIL PROTECTED]>
16) list archives?
by Harmon Seaver <[EMAIL PROTECTED]>
17) Re: Filter Caps on battery chargers
by "Michael A. Radtke" <[EMAIL PROTECTED]>
18) OT-CFs, Was: Filter Caps on battery chargers
by "David Chapman" <[EMAIL PROTECTED]>
19) Re: temporary EV heat
by "Chuck Hursch" <[EMAIL PROTECTED]>
20) Re: Possible LiOH charging thoughts
by "Chuck Hursch" <[EMAIL PROTECTED]>
21) Re: fu...ing tree hugger.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
22) Re: Prius Conversion
by "Jon \"Sheer\" Pullen" <[EMAIL PROTECTED]>
23) Re: Cold and old. Was: Mike's electric adventure
by Chris Zach <[EMAIL PROTECTED]>
24) Re: Mike's electric adventure
by Chris Zach <[EMAIL PROTECTED]>
25) Re: OT-CFs, Was: Filter Caps on battery chargers
by "Joe Smalley" <[EMAIL PROTECTED]>
26) Re: Filter Caps on battery chargers
by "David Chapman" <[EMAIL PROTECTED]>
27) RE: Prius Conversion
by "Roger Stockton" <[EMAIL PROTECTED]>
28) Distributed systems (was Re: Possible LiOH charging thoughts)
by Doug Weathers <[EMAIL PROTECTED]>
--- Begin Message ---
John Wayland wrote:
> See Ya......John Wayland
He he he.
Soluitions for being seen as a tree hugger.
Have a plackard that says or shows .... a punk peeing on Bin Laden.
Have the side of your EV covered with last years burnt rubber.
Have the gun rack in your EV, with one clearly missing....AKA on your
body as a clearly evident Six shooter.
Have so many scratches and rust on your EV that a Key mark shows up as
a CLEAN mark in your Moss/mold/rust collection.
Have the chain saw on board....
Know how to use it.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Michael Hoskinson wrote:
> ...old Hawker 26 Ah Genesis... we came up with the idea of making a
> series string of these and paralleling that with the floodies...
First: How cold are the batteries? Floodeds will sag from 96v to 84v at
300 amps even when warm. If they are cold, it will be even worse.
Second: What kind of shape are the Hawkers in? Cold will affect them,
too, especially as they approach dead. But, it these are old batteries
that have developed higher internal resistance, they might be unusable
at high currents even if warm. And, all it takes is one 'stinker' to
restrict the power of the whole string.
To figure out what is really going on, you'll have to add seperate
ammeters for the Hawkers and floodeds. Then you can see which ones are
supplying your current. It could easily be that the Hawkers aren't
really doing anything.
--
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 ---
Michael A. Radtke wrote:
> However, I picked up on the transformer having a capacitor directly
> connected to it. You may have "tuned" transformer, and yes the
> capacitor helps with the power factor.
Hi Michael. Your Lester has a "constant voltage transformer"; and yes,
it does have a capacitor connected directly across one of the windings.
The output voltage to only change about +/-2% when the AC line voltage
changes +/15%, and for load changes from 25%-100%. Pretty handy!
How it works is rather hard to explain. It is not using resonance. The
transformer is specially made with a lot of extra inductance in series
with the primary, and a core that will saturate. Such a transformer is
bigger, heavier, and noisier than a conventional transformer.
--
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 ---
Richard Furniss wrote:
> Yep, we have a problem! Chrysler didn't help the EV cause buy selling
> these things without a battery management system.
You'd think they *wanted* EVs to fail :-)
Actually, I think it is plain old ignorance. They assume they know
everything about batteries, since they have been using them for years in
ICE cars. So, they don't research what other successful EVs do, and
don't learn from the successes or failures of others.
> Here is the problem, the first GEM towed to the shop was one month
> old with something like six hours on the hour meter, three of the
> batteries were just under 11 volts (all voltages are with no load)
> one battery was 8.xx volts, one was 4.xx volts and the worst was
> -2.xx volts before the car wouldn't move anymore.
>
> Now if you had a system that would look at each individual battery
> and shut down the controller before battery damage...
All that's really needed is a) a controller that cuts back so you can't
pull the pack under 1.75v/cell, b) something like my Batt-Bridge to
serve as an 'idiot light' to tell the driver when there is a problem
like a dead cell and to stop driving. Ideally, the idiot light should
prevent the person from driving the EV at anything more than a crawl
until the problem is fixed.
--
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 ---
> Jim Coate wrote ...
> Date: Sat, 27 Dec 2003 13:02:23 -0500
> Subject: Re: 2004 Tour de Sol annouced
>
> So... it is now basically a static car show?
> Hang out in New York for 3 days doing show and tell.
> Then drive ~100 miles to Philly for another all day show.
> Then ~130 miles to DC for a final show.
>
> Pretty much leaves out any typical EV conversions, such as school team
> projects. Unless they just trailer the car from show to show.
>
> But good for biodiesel, natural gas, and hybrid (gasoline "never have to
> plug it in") vehicles. Hmmm... hopefully others will see more positives
> for battery EV's?
I passed this note along to Nancy Hazard, Director of the Tour de Sol and
she sends the following back.
Nancy Hazard wrote ...
If you have a battery EV, don't be shy! We expect very lively competition for
battery EVs at the Tour de Sol next May, as well as many other alternative
fueled vehicles. In fact, from a competative perspective, we have one more
reliability run compared with last year.
We are still working out the details of the scheduling of the competition, but
follwing is a rundown of planned competative events.
While the Tour is in Westchester County, all vehicles will earn points for
numerous events:
Acceleration short and/or long test
Handling cone test + Autocross at Westchester or in Tretnon
Reliability a 40-50 mile loop which will start and end at
the Westchester site.
There will be two additional reliability runs - one from Westchester to the
overnight location, and one from the overnight location to the event in Trenton
NJ.
Range A range event will be held on Sunday and be connected
with the reliability run from Westchester County to
our overnight stop.
Efficiency Efficiency score will be based on recharging data
collected after each reliability and/or range events.
Greenhouse gas emissions are calculated from effiency
data collected above.
The final run from Trenton, NJ to Washington, DC will not be scored for any
vehicles. We invite entrants to trailer or drive their vehicles to the final
destination as they see fit.
For the first time we are also offering competative events and prizes for
neighborhood electric vehicles, electric bikes, scoooters etc.
If you have any further questions, please let me know!
Nancy Hazard
Tour de Sol Director
Northeast Sustainable Energy Association
[EMAIL PROTECTED]
413 774-6051 x18
--
Mike Bianchi
--- End Message ---
--- Begin Message ---
Well, I haven't got the battery warming optimized yet - mainly
I've been either keeping the car in town where I can park indoors
or driving it around a lot to keep the pack warm. The pack was
about 20C when I tried the range run into town. I haven't had
time to properly fix the shift linkage yet.
I cycled the Hawkers a few times before attaching the string to
the floodeds. There was some strange behaviour. I'd discharge 10
Ah, then charge at a starting current of 20 amps. When the
acceptance voltage was reached (set at ~14.7 volts per 12 v
battery, corrected roughly for temperature), the current would
drop off quite rapidly (sorry I did not note the time) and with
current at only 0.5 amps, the emeter Ah reading had not even
reached zero, but was -1 Ah or worse. I concluded that the
acceptance voltage was too low, so I cranked the voltage limit up
a bit, and restarted the PFC at ~15 amps. Still didn't get near
zero before the amps dropped to near nothing. Now I wonder if
the emeter was playing tricks on me, with overestimaton of the Ah
consumed because I did not change the Peukert exponent. Or maybe
the charge efficiency was that much different? Who knows.
Anyway, after a cold night in between day 1 and day 2, with the
batteries quite cold in the morning, their resting voltages were
all 13.0-13.1.
I'll have to get another shunt and monitor that string like Lee
suggests.
Mike
Lee Hart wrote:
Michael Hoskinson wrote:
...old Hawker 26 Ah Genesis... we came up with the idea of making a
series string of these and paralleling that with the floodies...
First: How cold are the batteries? Floodeds will sag from 96v to 84v at
300 amps even when warm. If they are cold, it will be even worse.
Second: What kind of shape are the Hawkers in? Cold will affect them,
too, especially as they approach dead. But, it these are old batteries
that have developed higher internal resistance, they might be unusable
at high currents even if warm. And, all it takes is one 'stinker' to
restrict the power of the whole string.
To figure out what is really going on, you'll have to add seperate
ammeters for the Hawkers and floodeds. Then you can see which ones are
supplying your current. It could easily be that the Hawkers aren't
really doing anything.
--- End Message ---
--- Begin Message ---
Chris Tromley wrote:
I had thought (naively, perhaps) that you should be able to parallel a
small stiff pack with a bigger flooded pack of the same nominal voltage.
I would think the stiffer pack would sag less and therefore carry you
through the big amp draws, while for lower current draws they'd just be
loafing or "recharging" off the floodeds. Of course you'd have to
charge the two packs separately, but it still seemed an attractive
concept.
That's what I thought (naively) too. I'm trying it out because I
already have the SLA's sitting around doing nothing.
Perhaps Mike's packs are too different? His floodeds are what, 90 lb.
each? It may be asking too much of a 22 lb. Hawker to do the heavy
lifting for very long. I'm still confused as to why the added Hawkers
might make the car feel more sluggish.
I'm thinking that it might simply be the added weight. I'm going
to do some more rigorous testing over the next couple of weeks.
I also have some 17Ah Panasonics that are old but unused, to take
the concept to a ridiculous extreme. (the 250HC's are 78 lbs
each). I'll try separate runs with the auxiliary pack switched
in and out and multiple repeats. It will be hard to get good
data, however, since so many variables will be hard to control,
such as battery temperature. I have just been charging the
strings together so far, on the assumption that the floodies take
most of the current. When I charged the Hawker string
separately, the current on the PFC50 dropped to 0.5 amps before
the Ah reading on the emeter had reached zero. Strange, I
thought, and bumped the voltage up a bit for the next charges.
Eventually the finish voltage was the same as what I have been
charging the floodies at, so I figured I could just charge the
two strings together.
Or maybe there's an issue if the two nominally identical packs have
resting voltages that are several volts different? Gurus? This seems
like one of those questions that appears quite simple, yet is
deceptively subtle and tricky. Well, to this dolt, anyway.
Chris
This dolt too.
Mike
--- End Message ---
--- Begin Message ---
Gary Graunke wrote:
> I matched the Maxell 2600 vs Hawker Genesis 13AH.
> The specific power of the Hawker, discharging to 1.75 Volts
> per cell, was 240 w/kg, vs 504 w/kg for the ultracap. So the
> ultracap has over twice the power per weight.
Not to put too fine a point on it, but if you are looking at peak power
out of the Hawker, then you aren't looking at a 1.75Vpc endpoint, but
something lower. At 1.67Vpc they are up to 264W/kg (2min discharge
rate), so the ultracap is 'almost' twice the power per weight, not
'over'. ;^>
> So for my application, the ultracaps would be lighter but
> take up more space. They could get me off to a fantastic
> start (great for drag racing), but I need a bit more
> sustained energy to climb hills in my area.
I believe that the only benefit you would see performance-wise would be
due to the weight savings of the ultracaps since even the Hawkers are
capable of delivering more power than your inverter can take advantage
of.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Chris Tromley" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, December 29, 2003 9:37 AM
Subject: RE: Mike's electric adventure
> I had thought (naively, perhaps) that you should be able to parallel a
> small stiff pack with a bigger flooded pack of the same nominal voltage.
> I would think the stiffer pack would sag less and therefore carry you
> through the big amp draws, while for lower current draws they'd just be
> loafing or "recharging" off the floodeds. Of course you'd have to
> charge the two packs separately, but it still seemed an attractive
> concept.
Unless the car has regen, the pack voltage will not come up enough to put
*any* current back into the AGMs. Loafing is the better term.
> Perhaps Mike's packs are too different? His floodeds are what, 90 lb.
> each? It may be asking too much of a 22 lb. Hawker to do the heavy
> lifting for very long. I'm still confused as to why the added Hawkers
> might make the car feel more sluggish.
The added weight relative to the additional voltage/current being supplied
by the additional pack. If the controller is current limited, then the
loaded pack voltage determines the perforamnce. If the controller is 100%
PWM then the back EMF of the motor is controlling the performance and the
operator will need to shift up sooner to keep the pack power up to
compensate for the additional weight. If the shift points are the same, then
the motor current will not increase relative to the weight and the car will
feel slower just due to the weight difference.
> Or maybe there's an issue if the two nominally identical packs have
> resting voltages that are several volts different? Gurus? This seems
> like one of those questions that appears quite simple, yet is
> deceptively subtle and tricky. Well, to this dolt, anyway.
The packs will need to be charged separately if the charging profiles are
significantly different. Testing will be required.
The amount of power coming from each string can be measured if you have two
ammeters. One on each string as Lee stated earlier. At low currents,the
packs will share current according to the resting voltages. At high
currents, they will share inversely proportional to the pack impedences. As
the pack impedences change during discharge, the current ratio will change
as well.
> Chris
>
--- End Message ---
--- Begin Message ---
Michael Hoskinson wrote:
> Now I wonder if
> the emeter was playing tricks on me, with overestimaton of the Ah
> consumed because I did not change the Peukert exponent.
Actually, the E-meter records Ah consumed (i.e. removed from the pack)
faithfully, but 'discounts' Ah returned to it during charge according to
the charge efficiency factor. That is, if you remove 10Ah, the E-meter
will indicate -10Ah, but if you return 10Ah and your E-meter is using a
charge efficiency factor of 0.90, then the E-meter will indicate -1Ah
(-10Ah + 10Ah*0.9), not 0Ah.
The Peukert exponent is used by the E-meter during discharge, but only
affects the 'fuel guage' accuracy.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
John G. Lussmyer wrote:
> At 09:04 AM 12/25/2003 -0800, Rich Rudman wrote:
> >Nice battery but 50 amp draws over heat it, and the proper charge
> >algorithm has not been established.
>
> Depends on what you mean by "overheat". An hour at 56A
> brought my cells up to the 50-62 deg C range. Since they
> are rated to 70 deg C, this doesn't seem to be over temp.
I believe Rich was referring to the Evercel NiZn, not your Thundersky
Li-Ion.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Roger,
The Thundersky LiOn cells are spec'd at operating temp of -25 to 75 C.
http://www.thunder-sky.com/LP8581A(EN).htm
The Evercel NiZn cells are spec'd at -10 to 50 C. Charging is limited to 0
to 40 C.
http://www.evercel.com/featuresofnizn.html
Temperature Range: Nickel-zinc batteries can operate from -10�C (14�F) to
50�C (122�F) in normal load ranges and performance levels. At very high
power the temperature limits are narrower. Charging can be achieved at
temperatures from 0�C (32�F) to 40�C (104�F). Charging outside this range is
possible but shortens the life of the battery.
John Lussmyer is working with the Thundersky LiOn cells, so the information
was correct before - referring temperature to the LiOn cells.
BR,
Ed Thorpe
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Roger Stockton
Sent: Monday, December 29, 2003 1:13 PM
To: [EMAIL PROTECTED]
Subject: RE: Prius Conversion
John G. Lussmyer wrote:
> At 09:04 AM 12/25/2003 -0800, Rich Rudman wrote:
> >Nice battery but 50 amp draws over heat it, and the proper charge
> >algorithm has not been established.
>
> Depends on what you mean by "overheat". An hour at 56A
> brought my cells up to the 50-62 deg C range. Since they
> are rated to 70 deg C, this doesn't seem to be over temp.
I believe Rich was referring to the Evercel NiZn, not your Thundersky
Li-Ion.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Roger Stockton wrote:
> I believe Rich was referring to the Evercel NiZn, not your
> Thundersky Li-Ion.
However, re-reading Rich's post, I see I was mislead by the fact that he
was responding to a post that referred to the NiZn...
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
> Roger Stockton wrote:
>
> > I believe Rich was referring to the Evercel NiZn, not your
> > Thundersky Li-Ion.
>
> However, re-reading Rich's post, I see I was mislead by the
> fact that he was responding to a post that referred to the NiZn...
Nope... I'll get it right yet: even the original post was referring to
the Thundersky product.
I was just plain confused! ;^>
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
mailto:[EMAIL PROTECTED]
archives: http://infoarchive.net/sgroup/biofuel/
run by Keith Addison and Journey To Forever: http://journeytoforever.org/
Christian Kocmick wrote:
That big diesel-electric bus got me thinking. Does anyone know where
(or if) the biodiesel or veggie oil groups are?
Christian Kocmick
--
--
Martin Klingensmith
http://infoarchive.net/
http://nnytech.net/
--- End Message ---
--- Begin Message ---
Where are the archives for this list?
--- End Message ---
--- Begin Message ---
Lee,
Thanks for the additional information.
I did not use the word "resonance" on purpose. I used the word "tuned"
to imply that the capacitor must match the transformer or things won't
work as expected. I am concerned that David has such a transformer.
I think at one time Sola had the whole system pretty well patented and
had no competition. I am not up to date on whether anyone makes similar
units these days. Perhaps they are all obsolete based on power factor
correction (PFC) chips and switching devices that are now available.
Speaking of PFC chips, I took the time the other day to figure out how
they worked. Even with 99% of the complexity in the chip, there are a
still lot of external components to connect, tweak, and potentially
fail. I give a lot of credit to those who are building reliable
chargers using this technique.
I have been trying to use compact fluorescent lights (CFL) around the
house. After learning not to buy one specific brand which failed faster
than an incandescent light, I still have too high a failure rate. About
80% of these failures are in what's called the electronic ballast which
is largely a PFC chip circuit. Luckily about half of those failures are
repairable by fixing a bad connection or broken printed circuit trace.
Thanks again for your comments,
Mike
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Michael A. Radtke" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, December 29, 2003 3:21 PM
Subject: Re: Filter Caps on battery chargers
> Lee,
>
> Thanks for the additional information.
>
> I did not use the word "resonance" on purpose. I used the word "tuned"
> to imply that the capacitor must match the transformer or things won't
> work as expected. I am concerned that David has such a transformer.
>
> I think at one time Sola had the whole system pretty well patented and
> had no competition. I am not up to date on whether anyone makes similar
> units these days. Perhaps they are all obsolete based on power factor
> correction (PFC) chips and switching devices that are now available.
>
> Speaking of PFC chips, I took the time the other day to figure out how
> they worked. Even with 99% of the complexity in the chip, there are a
> still lot of external components to connect, tweak, and potentially
> fail. I give a lot of credit to those who are building reliable
> chargers using this technique.
>
> I have been trying to use compact fluorescent lights (CFL) around the
> house. After learning not to buy one specific brand which failed faster
> than an incandescent light, I still have too high a failure rate. About
> 80% of these failures are in what's called the electronic ballast which
> is largely a PFC chip circuit. Luckily about half of those failures are
> repairable by fixing a bad connection or broken printed circuit trace.
>
> Thanks again for your comments,
>
> Mike
Yes Lee, thanks. Mike you too. I probably was wrong to call the setup a
"ferro resonant" transformer setup. I had just heard the basic Lester
referred to that way and it seemed to me to be the same. On the CFs Mike,
was that brand by any chance "Commercial Electric" bought from Home Despot?
I bought 3 cases of those and they seemed to go like popcorn. Interesting
about the circuitry being a form of PFC device. I wonder if you could hack
one into a little "socket" wart with "manners"? Might be handy for charging
a E-scooter or E-bike when you can't find a plug. Regards, David Chapman.
--- End Message ---
--- Begin Message ---
For being on the cheap, you could have the cheap heater for the
windshield, and then a heated seat pad (JC Whitney, 4A, 50W,
~$35, takes a minute or two for noticeable heat) for your tush.
Save the expensive (in watts) cabin heater for when you really
need it. May have to be careful of overloading your cig lighter
circuit with all this high power...
----- Original Message -----
From: "Rod Hower" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, December 27, 2003 12:29 PM
Subject: Re: temporary EV heat
> I bought one of those cheap heaters.
> It makes lots of noise but it's good enough
> to prevent fogging on the window.
> It's not good for much else, including de-icing
> the window. I did have problems with condensation
> on the window from breathing, but don't count on it
> to warm up the vehicle, dress warm!
> Rod
> --- Jeff Shanab <[EMAIL PROTECTED]> wrote:
> > Our local harbor frieght has a ceramic heater that
> > can be placed on dash
> > and plugged into cigarette lighter for $6.47.(reg
> > $12.99 lol ) Just
> > thought I'd mention it for those who need something
> > NOW.
> >
--- End Message ---
--- Begin Message ---
Bill Dube wrote:
> >My thought was to use a DPDT relay on each battery, properly
rated. When
> >the relay is up, the + and - of the battery are connected in
series with
> >all the others in the string to form the 325 volt pack. When
the relay is
> >down, the battery taps into a common 12.6 volt charging bus.
So to charge,
> >you simply drop all the relays down, at which point, all
batteries are on
> >the 12.6 volt bus; thus the pack looks like one single massive
10.6 volt
> >battery under charge.
> >
> >As each battery hits full, it signals the control CPU, which
clears the
> >relay and stops charge on the battery. When all relays have
cleared, the
> >pack is charged, and the 325 volt bus has full power. Off you
go.
>
> Electric cars have been around for a long time. This
idea has been
> tossed around and then tossed out many times. It turns out to
be cost
> prohibitive. It also takes much longer to charge a pack battery
by battery
> rather than in series.
>
> I should note that simultaneous modular charging has
been done
> successfully. It can also be practical, but a touch more
expensive, and
> sometimes more complicated than series charging. This, and the
consequences
> of a single charger failure, are the reasons that modular
charging is not
> typically used.
How are the Rayovac renewable alkaline chargers, such as the PS2,
set up? It seems that each battery is monitored individually. I
wonder if it's something like 120VAC transformed down to ~2V.
Then there is some means of charging and controlling each bay.
Is there a ~2V power supply that all the bays run off of? I've
been thinking I should go google these chargers - maybe there is
such info out there. Additionally, you can charge nicads and
nimh batteries in these chargers, although that seems a bit more
problematic in my experience. The renewable alkalines I've had
very good success with. They charge fast and easy and have
lasted for years (for me).
The reason I'm curious per the EVDL is that this kind of
resembles the EV charging model I'm interested in. Once your
series charging is done and you've just hit gassing with your
hottest battery, you use just one large power supply to get from
AC to DC, with the DC being at the voltage to charge an
individual battery. However, this power supply is big enough to
charge all the batteries, if necessary, at some reasonable
amperage for the last part of the charge. Each battery's
charging rate is controlled by some central computer monitoring
through voltage sense wires. The actual hardware that the
computer controls might have to be some kind of small DC-DC
converter. This is where I get fuzzy and into the idea of what's
going on in the Rayovac charger.
I believe it was Dave Luiz who brought up the idea in a
discussion I had with him a few years ago this idea of a big AC
to DC power supply, if I understood him correctly. Good power
factor correction, etc. at this point. Hey, it might even be a
PFC charger of some sort, maybe even the same PFC charger that is
used for the series bulk charge. Then run DC - DC off of that.
Dave, any thoughts?
The reason I like the central computer idea is that you can roll
your own software algorithms to handle that last part of the
charge (and you can have whatever features you like). And it may
be possible to do some kind of "smoothing" through this network,
pulling up a weakest battery by charging it with 30A (or
whatever, but better than that puny 5A the Zivan Smoother had)
from the rest of the pack as you drive down the road. With the
modular chargers that people have tried, you're stuck with their
algorithm, and it seems that you are paying for duplicated power
supplies and a bunch of containers (all of which take up room and
power).
How much would individual 12V or 6V DC to DC computer
controllable power supplies cost? I don't think the one central
computer itself would be that expensive - it would just be a
small computer with enough power to run the charging scene and
give whatever other features you want. The big AC to DC unit
might be the expensive piece, but maybe comparable to a Rudman
PFC.
Not knocking anyone or their ideas, but from my perspective, it
seems that most of the solutions talked about on the EVDL for
charging issues are pure hardware, or nearly so. Maybe my
perspective as a software engineer not knowing much about
hardware skews how I see things.
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
http://www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
http://www.geocities.com/chursch/bizcard.bmp
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I didn't write it but I may have passed it on. Lawrence Rhodes......
> Lawrence wrote:
> I blame the social hostility created by the current administration
> against people like us [snip]
>
> meat wrote:
> >Well.
> >
> >You "people like us" jackasses keyed my Hummer.
>
> Since I doubt either of you keyed the others vehicle I suggest you
> blame someone else. Its not a Democrat/Republican issue. Its a
> criminal element issue, only anarchists support that kind of behavior.
>
> I'm sorry for the vehicle damage both of you have suffered. And now
> back to the topic of this list...
>
> Neon
>
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----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, December 29, 2003 1:13 PM
Subject: RE: Prius Conversion
> John G. Lussmyer wrote:
>
> > At 09:04 AM 12/25/2003 -0800, Rich Rudman wrote:
> > >Nice battery but 50 amp draws over heat it, and the proper charge
> > >algorithm has not been established.
> >
> > Depends on what you mean by "overheat". An hour at 56A
> > brought my cells up to the 50-62 deg C range. Since they
> > are rated to 70 deg C, this doesn't seem to be over temp.
>
> I believe Rich was referring to the Evercel NiZn, not your Thundersky
> Li-Ion.
Not any NiZn I've ever seen.
A hour at 56A and they're still mostly cold.
>From everything I've heard and know, sounds to me like the ThunderSkys. (Not
to mention the battery pack in my cell phone ;-))
S.
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You should take hawkers to 15 volts for 30 mins to polish off the
equalize. That said your Ah reading was due to the different perkeurt
factor between what your meter is set for and Hawkers (they're more
efficient during charge than T105's).
As for resting voltages, I am of the opinion that they are really
useless when looking at Hawkers. Mine always read 325-330 volts (300
base) after a charge, yet there is a big difference between a cold
hawker and a warm one. Currently after dragging 10ah from a cold string
I will be dropping into the 280s at 2C draw. Yet the pack voltage will
come back to 310 or so at 2amp load (idle)
Chris
Michael Hoskinson wrote:
Well, I haven't got the battery warming optimized yet - mainly I've been
either keeping the car in town where I can park indoors or driving it
around a lot to keep the pack warm. The pack was about 20C when I tried
the range run into town. I haven't had time to properly fix the shift
linkage yet.
I cycled the Hawkers a few times before attaching the string to the
floodeds. There was some strange behaviour. I'd discharge 10 Ah, then
charge at a starting current of 20 amps. When the acceptance voltage
was reached (set at ~14.7 volts per 12 v battery, corrected roughly for
temperature), the current would drop off quite rapidly (sorry I did not
note the time) and with current at only 0.5 amps, the emeter Ah reading
had not even reached zero, but was -1 Ah or worse. I concluded that the
acceptance voltage was too low, so I cranked the voltage limit up a bit,
and restarted the PFC at ~15 amps. Still didn't get near zero before
the amps dropped to near nothing. Now I wonder if the emeter was
playing tricks on me, with overestimaton of the Ah consumed because I
did not change the Peukert exponent. Or maybe the charge efficiency was
that much different? Who knows. Anyway, after a cold night in between
day 1 and day 2, with the batteries quite cold in the morning, their
resting voltages were all 13.0-13.1.
I'll have to get another shunt and monitor that string like Lee suggests.
Mike
Lee Hart wrote:
Michael Hoskinson wrote:
...old Hawker 26 Ah Genesis... we came up with the idea of making a
series string of these and paralleling that with the floodies...
First: How cold are the batteries? Floodeds will sag from 96v to 84v at
300 amps even when warm. If they are cold, it will be even worse.
Second: What kind of shape are the Hawkers in? Cold will affect them,
too, especially as they approach dead. But, it these are old batteries
that have developed higher internal resistance, they might be unusable
at high currents even if warm. And, all it takes is one 'stinker' to
restrict the power of the whole string.
To figure out what is really going on, you'll have to add seperate
ammeters for the Hawkers and floodeds. Then you can see which ones are
supplying your current. It could easily be that the Hawkers aren't
really doing anything.
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First: How cold are the batteries? Floodeds will sag from 96v to 84v at
300 amps even when warm. If they are cold, it will be even worse.
Really? This works out (in 12 volt land) to a 1.5 volt drop for each 12
volt battery. Assuming that the C/1hr rate rating for a T105 is about
100 amps then this is at a draw of 3C/1hr. In my-pack-land (300 volt,
52ah at c/10, 40ah at c/1) that would translate to a drop of 37.5 volts
or 262.50 volts at 120 amps.
I'd consider that a *very* low pack, time to be home quick. Question for
the masses: What is your typical voltage while motoring (reply with
volts and amps related to battery type and capacity)? when cold and
warm? I'm *really* curious for other people's real world data. Do
flooded batteries really drop this low?
At full charge, my batteries can put out 90amps min when at 0degrees C
and 180+amps at nice and warm temps without dropping below 12 volts per
battery (300 volts). 52ah AGM pack.
Chris
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According to the TI app note on driving CF lamps, the firing voltage is 1600
volts with a sustaining voltage of 300 volts.
If you hack into one of these, you might get a nice 100 mA 300 volt PFC
charger.
If your scooter uses 200 NiCad C cells, it might be just the ticket for an
overnight charger.
Does any scooter use 200 NiCads in series?
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "David Chapman" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, December 29, 2003 2:43 PM
Subject: OT-CFs, Was: Filter Caps on battery chargers
> Yes Lee, thanks. Mike you too. I probably was wrong to call the setup a
> "ferro resonant" transformer setup. I had just heard the basic Lester
> referred to that way and it seemed to me to be the same. On the CFs Mike,
> was that brand by any chance "Commercial Electric" bought from Home
Despot?
> I bought 3 cases of those and they seemed to go like popcorn. Interesting
> about the circuitry being a form of PFC device. I wonder if you could hack
> one into a little "socket" wart with "manners"? Might be handy for
charging
> a E-scooter or E-bike when you can't find a plug. Regards, David Chapman.
>
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Lee and Mike,
Sorry if I am still a little dense but one final question on the filter cap
thread. If its not going to cost me anything but a little wiring and
mounting (labor) to add a filter cap or two to the output of my charger do
you guys think it is a good idea to go ahead and do it? If so, what value
would y'all suggest? I just tested the DC output and it looks steady @ 15.6
V on my Fluke. Input was 122 VAC. Any suggestions appreciated. David
Chapman.
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Jon "Sheer" Pullen wrote:
> > I believe Rich was referring to the Evercel NiZn, not your
> > Thundersky Li-Ion.
>
> Not any NiZn I've ever seen.
>
> A hour at 56A and they're still mostly cold.
Unfortunately, you haven't seen all NiZn, not even Evercel's ;^>
The M100s I have tested rose at least 5C in 60min when discharged at a
paltry 14A, and they rose 15C at 34-35A. In my tests, the temperature
didn't rise very quickly for the first 20-30min, but by 60min it was
rising at a steady rate that didn't level off until shortly after the
discharge halted. I didn't try higher discharge rates, but have no
reason not to expect the temperature rise to be more pronounced at
nearly twice the discharge rate. Even if an hour at 56A only results in
20C rise, this is significant if the pack starts out at 30C.
The lighter Li-Ion cells may heat up *faster* than the heavier Evercel
modules, but the Evercels *do* heat up.
> From everything I've heard and know, sounds to me like the
> ThunderSkys. (Not to mention the battery pack in my cell
> phone ;-))
You're right, and I did finally manage to correct myself correctly on
that point ;^>
Cheers,
Roger.
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On Monday, December 29, 2003, at 11:06 AM, Chuck Hursch wrote:
Not knocking anyone or their ideas, but from my perspective, it
seems that most of the solutions talked about on the EVDL for
charging issues are pure hardware, or nearly so. Maybe my
perspective as a software engineer not knowing much about
hardware skews how I see things.
I have a similar problem - I'm a computer network guy (won't say
"engineer", no degree). I keep seeing distributed solutions, with
small modules that talk to each other over Ethernet or some other
network. Systems built of modules can also be scaled. Adding more
batteries? Just add modules instead of replacing your entire
monolithic charger.
An obvious application of this paradigm is modular battery charging. I
really like the idea - it's a shame I can't just buy a modular
charger/battery management/instrumentation system. Each battery gets
its own little computer that takes care of it and reports on its status
continuously. A battery module would be like a cross between a Soneil
charger, a PowerCheq, a digital multimeter, and an embedded web server.
Up in the dashboard, there would be a little computer like a web
browser that serves as the user interface and instrumentation. You
only need one of those.
Then there's my wacko idea of a distributed motor controller. Each
battery gets a switching module that switches it onto the motor power
bus when needed. If your throttle position is at 50%, half of your
batteries would be switched in. This would be like a contactor
controller, but each battery would be tapped, and the modules would
make sure the load was spread evenly across the pack. If you ask for a
voltage that's not an even multiple of 12v, the modules would use PWM -
but each module would be able to switch much slower, since there's one
for each battery (and they can coordinate their pulses so you get a
smooth sequence of them, kind of like the firing sequence in a piston
engine). Series-parallel motor switching, like the Zilla controllers
do, is left as an exercise for the reader.
Note that the two module ideas could be combined into a single
do-everything box, one per battery.
Note also that it becomes much less important that all the batteries
match each other in performance. They could vary considerably, perhaps
even in chemistry. A Marxist battery pack - "From each according to
his abilities, to each according to his needs."
I don't have the hardware or software skills to design or build any of
this stuff, or check it for feasibility. There are huge issues of
safety, reliability (hardware and software), packaging, and of course
cost to consider. I put the ideas out there for others to consider
while I slowly put together my own conventional EV. I'd sure love to
buy a set of these modules for my next car, though!
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
http://www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
http://www.geocities.com/chursch/bizcard.bmp
--
Doug Weathers
Bend, OR, USA
http://learn-something.homedns.org:8100/weblog/
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