EV Digest 5390
Topics covered in this issue include:
1) Re: longest range?
by "steve clunn" <[EMAIL PROTECTED]>
2) comparison of manufactured battery chargers?
by [EMAIL PROTECTED]
3) Re: Motors and 14-50 plugs
by "Tom Shay" <[EMAIL PROTECTED]>
4) Light bulbs plus zeners
by Christopher Zach <[EMAIL PROTECTED]>
5) Re: Light bulbs plus zeners
by "Mike Phillips" <[EMAIL PROTECTED]>
6) Re: Light bulbs plus zeners
by Christopher Zach <[EMAIL PROTECTED]>
7) Re: Light bulbs plus zeners
by Mike Phillips <[EMAIL PROTECTED]>
8) Re: Switched Capacitor Equalization of Long Strings WAS: Some
problemsto solve
by Lee Hart <[EMAIL PROTECTED]>
9) Re: Some problems to solve
by Lee Hart <[EMAIL PROTECTED]>
10) Re: VW Beetle
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
11) Re: Light bulbs plus zeners
by Lee Hart <[EMAIL PROTECTED]>
12) Re: 6 hp. Motor Needed
by Lee Hart <[EMAIL PROTECTED]>
13) Re: Light bulbs plus zeners
by Christopher Zach <[EMAIL PROTECTED]>
14) determining what motor type I've got
by Darin <[EMAIL PROTECTED]>
15) Re: VW Beetle
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
16) Honda 600 (in Texas?)
by [EMAIL PROTECTED]
17) RE: Light bulbs plus zeners
by Cor van de Water <[EMAIL PROTECTED]>
18) Arctic Leash
by Patrick Clarke <[EMAIL PROTECTED]>
19) Re: Arctic Leash
by Nick Viera <[EMAIL PROTECTED]>
20) Bucking in first gear
by Jeff Shanab <[EMAIL PROTECTED]>
21) RE: Light bulbs plus zeners
by Lee Hart <[EMAIL PROTECTED]>
22) RE: Bucking in first gear
by "Roger Stockton" <[EMAIL PROTECTED]>
23) Re: 6 hp. Motor Needed
by "Ryan Stotts" <[EMAIL PROTECTED]>
24) RE: Arctic Leash
by "Roger Stockton" <[EMAIL PROTECTED]>
25) Re: Bucking in first gear
by Mark Farver <[EMAIL PROTECTED]>
26) Round Trip Range on 48 volts
by "jmygann" <[EMAIL PROTECTED]>
27) Re: Battery comparison- Thanks for the answers.
by Neon John <[EMAIL PROTECTED]>
28) RE: Light bulbs plus zeners
by Dave Cover <[EMAIL PROTECTED]>
29) Re: Bucking in first gear
by "Roland Wiench" <[EMAIL PROTECTED]>
30) Re: Battery comparison- Thanks for the answers.
by "Roland Wiench" <[EMAIL PROTECTED]>
--- Begin Message ---
----- Original Message -----
From: "Charles Whalen"
I'm startin' to get nervous, Steve. I didn't realize you'd already done
this, run the course, a full 2 laps on a single charge, for 110 miles @ 45
mph.
I have a better set up now also , I've done a bit of long distance racing
, 3 years at the coco's Sunday Challenge . It's not a long boring drive ,
any more then the inda 500 would be . You have to know your batteries and
also figure how the way your driveling is going to change what you normally
see with them . Picking a speed that will give the most miles over 3hours ,
.
I'm thinkin' you might just kick my ass on 4/29. Wow, I can just see
it now -- "PbA beats NiMH on range!" I'll be limpin' all the way back
home
in shame!
Well , I'm 50% batteries weight and your 25% but yours hold 2time the
energy per lbs so we're close , there will be lots of light weight ,
orbites cars with 30 mile ranges , so far Its just you and I in the long
long rang group ,
Maybe somebody else will show up ,
Too embarrassed to tell the guys over on the RAV4 list that I got
my ass kicked by lead!
I don't think anybody will be switching to lead after :-)
Well, I can see that this is going to be some
serious competition and should be very close.
Yes and I hope your studying you meter's , seeing what speed uses how many
amp ect . Maybe some Long distance racers can give some tips .
Gonna be fun either way
whoever wins.
Yep , and we will have some hard mileage data .
Hope we might get Cliff in this as well so we can pit PbA vs.
NiMH vs. lithium, all chemistries against each other in one race.
Maybe more people will organize more long distance competitions , most
EV's are better set up for distance competition then drag racing , but the
drag racing seems to be getting the most attention right now :-) .
Steve Clunn
--- End Message ---
--- Begin Message ---
Hello,
I am a returning hobbyist to electric vehicles, now with a S10 EV with
flooded batteries. (haven't settled on 120,132, or 144)
1 Is there a good comparison of the technologies used in the
Russco, PFC, and Zivan (seem to be the economical and readily available
battery chargers).
I am leaning towards the PFC for its flexibility of input and high power
output.
I'm a chemEng, not EE,
2 so do they use transformer, rectifier's capacitors, or other technology
that gives one an advantage to "healthier" charge to the battery?
I had bad experiences with a K&W back in 98-99,
3 so would also appreciate any reliability experience with the 3 above
mentioned..
my experience with the Zivan's weren't bad other than the loss of
efficiency at the equalization.
4 If correct that the Zivan does a good top off/equalization of batteries
(semi smart), would the Russco and PFC do just as well a job if setup
properly by end user?
Thanks, Ben Fratto
New Jersey
--- End Message ---
--- Begin Message ---
Is this motor single-phase or three-phase? Most motors this size
are three-phase and I expect yours is. A 14-50 plug should be wired
for single-phase; a 15-50 plug is intended for three-phase use.
I'm not sure why a 14-50 outlet is rated for 3 hp. A 3 hp 240 volt
single-phase motor will draw about 15 amperes at full load. A
50-amp outlet could supply a larger motor but perhaps is rated
for only 3 hp to allow for starting current surge and an overloaded
or stalled motor.
----- Original Message -----
From: "Chris Tromley" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, April 19, 2006 3:43 PM
Subject: OT: Motors and 14-50 plugs
Hi Folks,
A change of employers has put me way behind on the list (again). I
will catch up eventually, but the new employer is working on a problem
I thought the list gurus might be able to shed some light on. I
certainly haven't had much luck with search engines.
We have a 5 or 6 hp 240 VAC hydraulic pump motor we'd like to power
from a 14-50 outlet. You'd think a 14-50 could put out around 12 hp
(even derated to 80% for continuous draw from the outlet), but the
specs on a Hubbell receptacle or plug are only 3 hp. It seems all
such outlets are similarly rated.
Does anyone know if this is a UL or NEC mandated limit? My guess is
that a motor starting under load would draw a big current spike as it
starts, causing arcs on the contacts that might turn into significant
resistance (and heating) after many repetitions.
Am I on track here? If it's not a hard-and-fast code rule I'm
thinking our specific application, which always starts the motor
unloaded, would work just fine. Am I missing something? Even if
testing proved it workable, would local code enforcers refuse to
approve it?
Chris
--- End Message ---
--- Begin Message ---
I'm looking at using Lee's lightbulb plus zener solution as a first gen
balancer for my Hawkers. However after looking thru the archives, it
appears that I can use either:
6.3 volt zeners
or
6.8 volt zeners.
Which would be better for Hawkers? The 6.8 volt ones look like they will
start to bypass at 13.6 or so, the 6.3 would be around 12.6.
Chris
--- End Message ---
--- Begin Message ---
I literally had to make up that simple circuit and test the "on"
voltage due to fairly large variances in the zeners on threshold and
the temperature. The range of "on" is over about 1.3 volts or so.
Before committing to buying all of the parts, test it out first. And
since you are in cold country, do it cold as well.
Mike
--- In [EMAIL PROTECTED], Christopher Zach <[EMAIL PROTECTED]> wrote:
>
> I'm looking at using Lee's lightbulb plus zener solution as a first gen
> balancer for my Hawkers. However after looking thru the archives, it
> appears that I can use either:
>
> 6.3 volt zeners
> or
> 6.8 volt zeners.
>
> Which would be better for Hawkers? The 6.8 volt ones look like they
will
> start to bypass at 13.6 or so, the 6.3 would be around 12.6.
>
> Chris
>
--- End Message ---
--- Begin Message ---
Mike Phillips wrote:
I literally had to make up that simple circuit and test the "on"
voltage due to fairly large variances in the zeners on threshold and
the temperature. The range of "on" is over about 1.3 volts or so.
Before committing to buying all of the parts, test it out first. And
since you are in cold country, do it cold as well.
*nod* I'll try it with 10, bought some 6.2 and 6.8 diodes for a mix and
match test. Mouser only had 18 light bulbs anyway :-) Anyone else using
this method?
Chris
--- End Message ---
--- Begin Message ---
Great idea getting a mix.
I think a resistor and led worked as well. Bulbs are wonderfully
current limiting however.
Mike
--- Christopher Zach <[EMAIL PROTECTED]> wrote:
> Mike Phillips wrote:
> > I literally had to make up that simple circuit and test the "on"
> > voltage due to fairly large variances in the zeners on threshold
> and
> > the temperature. The range of "on" is over about 1.3 volts or so.
> > Before committing to buying all of the parts, test it out first.
> And
> > since you are in cold country, do it cold as well.
>
> *nod* I'll try it with 10, bought some 6.2 and 6.8 diodes for a mix
> and
> match test. Mouser only had 18 light bulbs anyway :-) Anyone else
> using
> this method?
>
> Chris
>
>
Here's to the crazy ones.
The misfits.
The rebels.
The troublemakers.
The round pegs in the square holes.
The ones who see things differently
The ones that change the world!!
www.RotorDesign.com
--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
> Adding an inductor should not significantly change the price of this
> circuit ;-)
Perhaps. Details are important. The basic "textbook" circuits are simple
(just a few parts), but practical realizations tend to have a lot more
parts.
Look at any switchmode power supply that it is actually being used in a
commercial product. You'll find dozens of components. You could take
3/4th of them out and it would still work -- but it would have problems
with noise, over- or under-voltage, high/low temperature, overcurrent,
no-load, safety, etc.
> That should improve the efficiency, but not by a terrible amount
The circuit described in the patent uses an RC network to
charge/discharge the capacitor, where the "R" is a actually the internal
resistance of the capacitor, switches, batteries, wiring, etc. When you
go though the analysis, you'll find that RC charging of a capacitor
results in about half the energy being lost in the resistance,
regardless of power level.
Adding an inductor allows it to operate as a switching mode converter.
They can readily achieve efficiencies of 90% or better (as opposed to
50% for the RC network approach).
> So the idea is to make a version that has low current draw and leave
> it running forever -- that should take care of the issue of balancing
> in days...
Yes, it certainly helps. With both inductor and capacitor, and
appropriate control circuits, it can equalize the state of charge
between batteries.
> Using the simple formula for charge calculation to find a value for C:
> I x t = V x C say we want 1A of equalisation when the batteries are 1V
> out of whack and switching frequency is 100 us (10 kHz) then capacitor
> value is 100 uF.
The trouble is, a 1v imbalance is a *huge* error. Balanced 12v batteries
differ by less than 0.05v at zero current. When you are loading one to
charge another, the difference is even less.
Do the simple experiment I suggested in an earlier email. Get two
identical batteries. Charge them both, and discharge one by a known
amount (10 amphours or whatever). Connect them in parallel with an
ammeter (or better still, an E-meter) between them. Record the number of
amphours that transfer between them over a period of days. You'll find
that even 1 week isn't long enough to transfer half the amphour
imbalance between them.
Now, batteries directly connected in parallel is better than even the
most perfect capacitive balancer can achieve. This should tell you how
weak the balancing action really is. It works -- but just barely.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
>
> Hi Lee, Joe,
>
> You agree that my batteries are well balanced, but I hear
> conflicting info about the effect of my charging. If I hear
> you correct, Joe, then you say that I routinely charge a little
> too conservative (towards sulfation) while Lee indicated that
> I may lose water and dry out my batteries.
My perspective is that you are balancing via deliberate overcharging
(there are no shunt regulators or individual chargers). Long term, this
results in "death by overcharging".
A new AGM needs about 105% of the amphours removed to return to "full".
There will be about a 5% natural variation between batteries in a pack.
So, when the lowest one reaches "full" (105%), the worst has received 5%
too much (110%).
The ones that are getting 110% will have higher capacity, and will have
lower internal resistance. But they will also run a little warmer, and
be losing a little water on each charge cycle. Over time, the specific
gravity rises inside. When it gets up past 1.300, it is strong enough to
start attacking the plates themselves. As the plates are dissolved, the
internal resistance rises. This is called grid corrosion.
Doing this to a battery makes it perform well for its "rated" cycle
life; but then its capacity rapidly falls and its internal resistance
rapidly rises. An old battery like this has fairly good capacity at low
discharge currents, but terrible at high currents. On charge, its
voltage tends to rise too fast and too high.
In contrast, the batteries in that series string that were receiving a
little less charge per cycle won't have quite as high a capacity or as
low an internal resistance. But as they age, their capacity drops off
slower, and they will last longer and their internal resistance doesn't
increase as much.
Just to complete the picture, if there were batteries you weren't
charging enough in this string, they will be chronically low in voltage.
Their capacity will also fall early. Their internal resistance will be
low when charged, but will increase dramatically as they are discharged.
Sometimes these problems are reversible; you can "fix" it by hard
charging and equalization.
> BTW Lee, the effect that I hear from others when their
> batteries get dry, due to the increased acidity (high SG)
> they have very stiff batteries but with reduced range,
> can you explain why you say their internal resistance
> will rise?
It only rises when the battery gets old (see above).
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
On the west coast VWbugs are plentiful and cheap. One day I found 30 of
them on Craigs List.
http://www.craigslist.org/eby/car/152906523.html this one is free.
http://www.craigslist.org/cgi-bin/search?areaID=1&subAreaID=0&query=VW+bug&catAbbreviation=car&minAsk=min&maxAsk=max
Here are 50 with some new beetles mixed in. They are in every sort of state
of repair. Needless to say I could get one for free no problem with a rust
free pan. LR............
--- End Message ---
--- Begin Message ---
Christopher Zach wrote:
> I'm looking at using Lee's lightbulb plus zener solution as a first
> gen balancer for my Hawkers. However after looking thru the archives,
> it appears that I can use either:
>
> 6.3 volt zeners
> or
> 6.8 volt zeners.
>
> Which would be better for Hawkers? The 6.8 volt ones look like they will
> start to bypass at 13.6 or so, the 6.3 would be around 12.6.
I've built a few versions, to test ideas. Typical of my work, the design
is more subtle than it seems (one wag labelled it a "Hartian design :-)
The first version used two 6.8v 5w zeners and a #PR2 lamp. It started
working over 13.8v. As the zeners heated up, their zener voltage rose,
so it tended to be self-limiting (if they got too hot, they
automatically reduced their current). But this temperature compensation
was the opposite of what was desired for the battery (they should get
LESS voltage as their temperature goes up).
The next version used two 6.2v 5w zeners. It started working at 12.4v,
which turned out to work better; the regulators bypass current over a
longer period of time, and thus balance more aggressively. But the
voltage was low enough that they kept bypassing small amounts of current
even with the charger off. Their temperature coefficient was negative,
but a bit too strong; they could go into thermal runaway under certain
conditions.
Next, I tried putting an ordinary diode in series, to raise the
threshold 0.6v and provide reverse polarity protection (won't burn out
the bulb if you hook it up backwards). But this pushed the temperature
compensation in the wrong direction.
My current choice is one 6.2v and one 6.8v zener, with a #PR2 lamp and
10 ohm resistor in series. The combination of zeners gives a 13v
threshold, to draw negligible current from a fully charged battery, but
will still balance even with a float charger. They also have the right
temperature coefficient. The resistor is just there so the regulator
will still work (but with reduced effectiveness) even if the lamp gets
broken or burns out.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
jmygann wrote:
> Where can I find "the newer separately excited ones" ?
Old golf carts (and many cheaper ones today) use plain old series
motors. Newer, and the more expensive ones use separately excited
motors. You can buy them from any of the manufacturers or parts dealers
for golf carts.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I've built a few versions, to test ideas. Typical of my work, the design
is more subtle than it seems (one wag labelled it a "Hartian design :-)
Neat. I like to experiment a bit as well. This should be fun.
The next version used two 6.2v 5w zeners. It started working at 12.4v,
which turned out to work better; the regulators bypass current over a
longer period of time, and thus balance more aggressively. But the
voltage was low enough that they kept bypassing small amounts of current
even with the charger off. Their temperature coefficient was negative,
but a bit too strong; they could go into thermal runaway under certain
conditions.
*nod* makes sense, but out of curiousity what happens if the charger
overpowers the regs? I typically charge at 5a rate up to 350 or so (14
volts per battery), then down to 1a for the run to 375 (15). Would I
need to dial this back?
My current choice is one 6.2v and one 6.8v zener, with a #PR2 lamp and
10 ohm resistor in series. The combination of zeners gives a 13v
threshold, to draw negligible current from a fully charged battery, but
will still balance even with a float charger. They also have the right
temperature coefficient. The resistor is just there so the regulator
will still work (but with reduced effectiveness) even if the lamp gets
broken or burns out.
Got it. I assume the resistor also a 5 watt rated one?
I ordered a small batch o parts from mouser, will give this a try next
week. The new batteries should be in by next weekend as well, so if this
does work, then I can just pop 50 of them into the car and see what
happens. Can't make things too much worse :-)
On another question, what do you think is the reason these batteries
keep blowing 1-2 cells without damaging the others? Dry-out or shorts? I
can understand the whole battery drying out or sulfating, but why only
1-2 cells? And why go to zero volts instead of going into reversal?
Chris
--- End Message ---
--- Begin Message ---
Lee A. Hart wrote:
Old golf carts (and many cheaper ones today) use plain old series
motors. Newer, and the more expensive ones use separately excited
motors.
OK, time to step out from lurk mode and continue to reveal my ignorance...
I have followed several threads over the past month or so which dealt
with the differences between series/shunt/compound/separately excited
motors. I'm still not sure which type of motor mine is (the drive motor
I pulled from my surplus forklift).
How does one figure this out? The motor has 4 terminals and field
weakening on the control board, so I assume that rules out a straight
series type.
Beyond that, though, I'm not sure whether I've got a SepEx, Compound or
Shunt (though I have read that shunt motors like to run at a constant
rpm, and clearly that is not what a forklift drive motor is designed for.)
The Wikipedia entry on DC motors doesn't mention SepEx at all.
Can anyone illuminate?
- Darin
(PS - new shoestring budget Metro host car located and purchased, with
the "non-oxidized floor" option specified this time! Parts from the
holey Swift have already been cannibalized to prepare the Metro for a
successful safety inspection prior to de-ICEing.)
--- End Message ---
--- Begin Message ---
http://www.craigslist.org/sby/car/152268694.html Here is a Convertible
Creampuff that needs a top. One Thousand Dollars. LR........
----- Original Message -----
From: "John Norton" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, April 19, 2006 5:27 PM
Subject: Re: VW Beetle
On Tue, 18 Apr 2006 19:22, Alan Smith wrote:
A friend of mine wants to convert to an ev because he only drives about
10-15 round trip for work. And occasionally takes his kids places around
town. The first question is, what car should he use as a donor? Now, I
know
almost nothing about cars, but I was thinking a VW Beetle because they're
small and it shouldn't take much to power them. What do you all think?
There are a number of ev sites that have a donor selection faq. In
general, lighter is better, and you want a manual transmission. And it
needs to have some space to put batteries and a chassis that is up to it.
There are other things like not wanting a rusty car (which you don't want
regardless) and some advice to pick a car you like, because if you don't
like it, your ev experience will be lesser.
The Beetle was originally a 36 hp car, so it doesn't take much to match or
beat the performance of those cars, though they were mostly more powerful
than that. They are simple, with few electrical needs, parts are
plentiful and cheap - a whole section of JC Whitney devoted to just
Beetle's. They have a certain style that a more modern small car lacks -
who covets a Geo, for example? Not downing Geo's, just on a desire level,
there is no comparison.
All of that being said, the downside is that these are 30 to 40 year old
cars. Finding one in decent shape could be a challenge, especially if you
are on the East coast. One that has been restored to a very good
condition is likely to be $5k or more - sometimes much more. Plus, they
lack many safety features we take for granted - a lot don't have rear seat
belts or shoulder belts in the front, a lot have drum brakes all the way
round that would be scary slowing a car a thousand pounds or so heavier
than designed, so you'd have a further expense and difficulty upgrading
that. I'm not a bug expert, but I think a super beetle takes care of
most of those issues.
In my search for a donor car, I have just about ruled out a beetle barring
some incredibly lucky barn find of a great body sans motor that someone
wants to sell cheap nearby.
There are any number of newer, relatively light manual transmission
vehicles with disc brakes etc. Hondas, toyotas, nissans, escorts, geos,
vw rabbits, etc. in decent enough condition for under $2k - remember you
are adding $5-10k to the car, so unless money is not important to you, a
cheaper donor is better.
Another thing to take into account is the availability of adapters - seems
to me that this is the hardest part for a do-it-yourselfer. Beetle
conversions are plentiful, so they are available. You can check out
Electroauto and KTA and cloudelectric for what they already have plans
for. They are relatively pricey, but unless you have a metal shop in the
grarage, chances are it is still cheaper than the time you would spend
yourself. I know it can be done, it all depends on how much time vs money
you want to spend.
As for lead acid, surrounding yourself with half a ton of hazardous
materials sounds like a bad idea, but it is what it is. Probably
comparing to the explosive power of a tank of gas won't win that argument,
but I bet a look at the price of exotic batteries (at this point) would.
Probably sealed batteries might sound less scary, and there are plenty of
people running them.
John F. Norton
via T-Mobile Sidekick
--- End Message ---
--- Begin Message ---
This microcar might make be a good basis for an EV (for someone else, that is):
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4631382724
--- End Message ---
--- Begin Message ---
Lee wrote:
> My current choice is one 6.2v and one 6.8v zener, with a #PR2
> lamp and 10 ohm resistor in series.
I assume you meant "resistor PARALLEL with the lamp" as it
will not help when the bulb breaks and it is in series.
(This was actually my biggest worry with your balancer,
becoming an unbalancer when one of the bulbs go out.
With the resistor it is much more resilient.
Personally I would forego the bulb just to make it last)
If the batteries are charged up to 15V (and are balanced) then the
resistor will get only 2V, resulting in 0.2A => 0.4Watt in the
resistor.
When the batteries are taken up to 16V then the resistor needs to
be dimensioned for the 3V, 0.3A = 0.9Watt
So a 1-watt resistor should be OK to give a decent balancing.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Lee Hart
Sent: Thursday, April 20, 2006 12:42 PM
To: [email protected]
Subject: Re: Light bulbs plus zeners
Christopher Zach wrote:
> I'm looking at using Lee's lightbulb plus zener solution as a first
> gen balancer for my Hawkers. However after looking thru the archives,
> it appears that I can use either:
>
> 6.3 volt zeners
> or
> 6.8 volt zeners.
>
> Which would be better for Hawkers? The 6.8 volt ones look like they will
> start to bypass at 13.6 or so, the 6.3 would be around 12.6.
I've built a few versions, to test ideas. Typical of my work, the design
is more subtle than it seems (one wag labelled it a "Hartian design :-)
The first version used two 6.8v 5w zeners and a #PR2 lamp. It started
working over 13.8v. As the zeners heated up, their zener voltage rose,
so it tended to be self-limiting (if they got too hot, they
automatically reduced their current). But this temperature compensation
was the opposite of what was desired for the battery (they should get
LESS voltage as their temperature goes up).
The next version used two 6.2v 5w zeners. It started working at 12.4v,
which turned out to work better; the regulators bypass current over a
longer period of time, and thus balance more aggressively. But the
voltage was low enough that they kept bypassing small amounts of current
even with the charger off. Their temperature coefficient was negative,
but a bit too strong; they could go into thermal runaway under certain
conditions.
Next, I tried putting an ordinary diode in series, to raise the
threshold 0.6v and provide reverse polarity protection (won't burn out
the bulb if you hook it up backwards). But this pushed the temperature
compensation in the wrong direction.
My current choice is one 6.2v and one 6.8v zener, with a #PR2 lamp and
10 ohm resistor in series. The combination of zeners gives a 13v
threshold, to draw negligible current from a fully charged battery, but
will still balance even with a float charger. They also have the right
temperature coefficient. The resistor is just there so the regulator
will still work (but with reduced effectiveness) even if the lamp gets
broken or burns out.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
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--- Begin Message ---
Greetings EV'ers!
Now that it's raining less often here in the PNW, I'm looking at
wrapping up some loose ends on our Geo Metro conversion (we've been
delayed by being temporarily garage-less). To wit; not wanting to have
to leave the hatchback open for the charging cable, I'd like to
incorporate the "traditional" charging-plug-through-the-gas-cap routine.
Does anyone have a better/easier/cheaper retracting solution than
mounting something like this Arctic Leash in the car?
http://tinyurl.com/fykvv
Is it heavy enough gauge for a 120V system?
Thanks in advance!
- Pat Clarke
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--- Begin Message ---
Hi Patrick,
Patrick Clarke wrote:
http://tinyurl.com/fykvv
Is it heavy enough gauge for a 120V system?
That depends primarily on the current limit of your charger and/or how
fast of a rate you plan to charge at...
Assuming you have a charger that can take full advantage of the power
supplied by a 120-Volt outlet; then you'll probably want to move up to
at least 12 AWG wire, so you can safely pull 15-20 Amps when you get the
chance (i.e. aren't sharing a 120-Volt circuit with something else)
IMHO, it is especially worth going to a larger size wire if you plan on
having a long charging cord (say, 50+ feet). This will help reduce
voltage drop through the wiring and allow you to get as much power as
possible from the 120-Volt outlet, while keeping the cordage cooler ;-)
My 0.333 kWh,
--
-Nick
1988 Jeep Cherokee 4x4 EV
http://go.DriveEV.com/
http://www.ACEAA.org/
--------------------------
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--- Begin Message ---
I drive around in second and 3rd, sometimes 4th in my 300zx (zilla1k on
24 orbitals)
Yesterday I decided to check accelertion in first instead of second and
it bucked wildly even at part throttle.
I was wondering how current limit and voltage limits are handled in the
hairball and what was happening.
My motor voltage limit is set for 170, my battery amps limit is set for
1000 and my low battery voltage limit is set for 240V.
--- End Message ---
--- Begin Message ---
Lee wrote:
>> My current choice is one 6.2v and one 6.8v zener, with a #PR2
>> lamp and 10 ohm resistor in series.
Cor van de Water wrote:
> I assume you meant "resistor PARALLEL with the lamp" as it
> will not help when the bulb breaks and it is in series.
Correct! The two zeners and lamp are all in series. The 10 ohm resistor is in
parallel with the lamp.
>(This was actually my biggest worry with your balancer,
>becoming an unbalancer when one of the bulbs go out.
>With the resistor it is much more resilient.
>Personally I would forego the bulb just to make it last)
It will work with just the resistor. However, the lamp provided a convenient
visible indicator,
and it draws a more constant current than a simple resistor.
--
Lee Hart
--- End Message ---
--- Begin Message ---
Jeff Shanab [mailto:[EMAIL PROTECTED] wrote:
> My motor voltage limit is set for 170, my battery amps limit
> is set for 1000 and my low battery voltage limit is set for 240V.
What's the rev limit set to?
In low gear the motor voltage or rev limits are the ones you're most
likely to bang against.
Roger.
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--- Begin Message ---
Golf cart motors:
http://www.evparts.com/shopping/index.php?id=525
6hp continuous:
http://www.evparts.com/shopping/product_details.php?id=532&product_id=1102
Some more motors to check out:
http://www.cloudelectric.com/category.html?UCIDs=1320716
--- End Message ---
--- Begin Message ---
Patrick Clarke [mailto:[EMAIL PROTECTED] wrote:
> I'd like to incorporate the "traditional"
> charging-plug-through-the-gas-cap routine.
>
> Does anyone have a better/easier/cheaper retracting solution than
> mounting something like this Arctic Leash in the car?
> http://tinyurl.com/fykvv
>
> Is it heavy enough gauge for a 120V system?
The issue with any retracting type cord setup is that if the cord is not
fully unrolled while in use, then it can overheat and fail.
The 12ft 15A 14/3 version is probably OK for use with a charger, but it
depends on the nature of the charger. If the charger has a high crest
factor (poor power factor, high peak current on the AC side), then even
though it may appear to draw a reasonable current things may still
overheat and fail.
Have you considered instead mounting a flanged inlet type recepacle in
place of the original fuel filler and just plugging in an appropriate
extension cord? I've put a NEMA L14-30 on mine and it is very nearly a
drop in replacement for the fuel filler. If you are only concerned with
120VAC charging, you could get away with a NEMA L5-30 (or even smaller;
the 5-30 is rated for 30A) flanged inlet (this is the male half of the
connector pair).
I know the locking style connectors are out of favour with some in
earthquake zones, but as far as I'm concerned if my EV moves far enough
relative to the outlet that this becomes an issue there are far larger
issues to worry about! ;^>
Cheers,
Roger.
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--- Begin Message ---
Jeff Shanab wrote:
I drive around in second and 3rd, sometimes 4th in my 300zx (zilla1k on
24 orbitals)
Yesterday I decided to check accelertion in first instead of second and
it bucked wildly even at part throttle.
I've seen this too... after using the Hairball in DAQ mode I discovered
that most of the effect was actually caused by my foot coming off the
pedal. The Zilla has pretty quick throttle response. Side the seat
forward and pound the pedal to the floor and the problem lessens (in my
MR2 acceleration is enough that the collapse of the seat padding is
enough to lift my foot...I wouldn't be a good racer) Look for places in
the throttle cable where the high forces might be affecting the pot
setting. Adding additional return springs seems to help by giving you a
greater force to work against. the curtis springs are way too light.
The other problem could be electrical.. loose connections and the like.
Mark
I was wondering how current limit and voltage limits are handled in the
hairball and what was happening.
My motor voltage limit is set for 170, my battery amps limit is set for
1000 and my low battery voltage limit is set for 240V.
--- End Message ---
--- Begin Message ---
My first try ...
Things I was able to measure ....
22.7 miles elapased time - 47 minutes
100 amp draw @ 35mph
4 door Geo Metro 8 stop and go's
ending speed 45 mph ....
47.3 volts in pack at end of run ... What is 50% discharge ? 80% ?
--- End Message ---
--- Begin Message ---
On Thu, 20 Apr 2006 07:36:12 -0400, "Richard Acuti"
<[EMAIL PROTECTED]> wrote:
>Orbitals, Optimas and Hawkers make great performance batteries (read: high
>acceleration) because they can safely discharge at extremely high rates and
>have little voltage sag when they do. However, you -may- sacrifice range
>because they don't discharge as long.
No. If one compares equal amp-hours between performance and flooded
batteries, the high performance batteries will go farther because the
Peukert effect is so much lower (implied in the very low internal
resistance that lets the performance batteries perform.)
The major difference between performance and flooded batteries other
than performance is cost. Lots of difference.
>Conventional floodeds and the NiCad's I asked questions about earlier have
>the advantage of cost and long discharge times which are good for range, but
>they don't tolerate high discharge rates well and experience voltage sag
>plus extra weight so I should expect slower acceleration.
Separate floodeds and wet NiCads. Wet NiCads generally also fall in
the performance class, capable of large discharge rates for the AH
rating. NiCads do NOT sag unless very heavily loaded. About the only
disadvantages that I can think of with Nicads are a) cost, lots of
cost, and b) the necessity of frequent watering.
If you have the money and room, then performance batteries are the way
to go. Either parallel or series them to get the watt-hours you need
for your required range.
If you have even more money, NiCads are the way to go. Not only are
they capable of high performance but also, unless you REALLY abuse
them, they're a lifetime purchase. You'd be able to move the pack
from car to car.
Of course, if you have more money than you know what to do with then
there is, of course, the various Li chemistries.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
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--- Begin Message ---
Does this scale down to 1.2 volt cells?
--- Lee Hart <[EMAIL PROTECTED]> wrote:
> Date: Thu, 20 Apr 2006 19:32:10 -0400 (EDT)
> From: Lee Hart <[EMAIL PROTECTED]>
> To: [email protected]
> Subject: RE: Light bulbs plus zeners
>
> Lee wrote:
> >> My current choice is one 6.2v and one 6.8v zener, with a #PR2
> >> lamp and 10 ohm resistor in series.
>
> Cor van de Water wrote:
> > I assume you meant "resistor PARALLEL with the lamp" as it
> > will not help when the bulb breaks and it is in series.
>
> Correct! The two zeners and lamp are all in series. The 10 ohm resistor is in
> parallel with the
> lamp.
>
> >(This was actually my biggest worry with your balancer,
> >becoming an unbalancer when one of the bulbs go out.
> >With the resistor it is much more resilient.
> >Personally I would forego the bulb just to make it last)
>
> It will work with just the resistor. However, the lamp provided a convenient
> visible indicator,
> and it draws a more constant current than a simple resistor.
> --
> Lee Hart
>
>
--- End Message ---
--- Begin Message ---
Hello Jeff,
Mark's comment of the Curtis spring is also true. I took the end of that
spring off the stop, and rotated it counter clockwise and held it with a
small stainless cable clamp which is fasten to a small screw that holds on
the pot box cover. This gave it more tension.
Also look at your Low Battery Voltage LBV setting. Some racers drop this
way down to about 1/2 there battery pack voltage, because of a large voltage
sag in lower amp hour batteries when pulling a high battery ampere.
I do not do any racing or hard acceleration, so in my 180 volt battery pack
I have my LBV set at 150 volts and the LBVI set for 157 volts. This is 5.23
volts per 6 volt battery for me. Any time the Low Battery Voltage Indicator
lights up, even if it's a voltage sag, than I try to drive the EV so the
voltage will stay above this level, until I get it charge.
Roland
----- Original Message -----
From: "Jeff Shanab" <[EMAIL PROTECTED]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, April 20, 2006 5:28 PM
Subject: Bucking in first gear
> I drive around in second and 3rd, sometimes 4th in my 300zx (zilla1k on
> 24 orbitals)
>
> Yesterday I decided to check accelertion in first instead of second and
> it bucked wildly even at part throttle.
>
> I was wondering how current limit and voltage limits are handled in the
> hairball and what was happening.
>
> My motor voltage limit is set for 170, my battery amps limit is set for
> 1000 and my low battery voltage limit is set for 240V.
>
>
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Neon John" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Thursday, April 20, 2006 7:29 PM
Subject: Re: Battery comparison- Thanks for the answers.
> On Thu, 20 Apr 2006 07:36:12 -0400, "Richard Acuti"
> <[EMAIL PROTECTED]> wrote:
>
>
> >Orbitals, Optimas and Hawkers make great performance batteries (read:
> >high
> >acceleration) because they can safely discharge at extremely high rates
> >and
> >have little voltage sag when they do. However, you -may- sacrifice range
> >because they don't discharge as long.
>
> No. If one compares equal amp-hours between performance and flooded
> batteries, the high performance batteries will go farther because the
> Peukert effect is so much lower (implied in the very low internal
> resistance that lets the performance batteries perform.)
>
> The major difference between performance and flooded batteries other
> than performance is cost. Lots of difference.
You got that right. I just contacted Hawkers and they wanted $24,000.00
for a set of batteries that would be equal to a 300 AH PbA battery. There
would be so many of them in parallel and series that I could not fit them in
anyway. And that's not including the BMS. I can buy 10 sets of battery
packs for that cost. Roland
>
> >Conventional floodeds and the NiCad's I asked questions about earlier
> >have
> >the advantage of cost and long discharge times which are good for range,
> >but
> >they don't tolerate high discharge rates well and experience voltage sag
> >plus extra weight so I should expect slower acceleration.
>
> Separate floodeds and wet NiCads. Wet NiCads generally also fall in
> the performance class, capable of large discharge rates for the AH
> rating. NiCads do NOT sag unless very heavily loaded. About the only
> disadvantages that I can think of with Nicads are a) cost, lots of
> cost, and b) the necessity of frequent watering.
>
> If you have the money and room, then performance batteries are the way
> to go. Either parallel or series them to get the watt-hours you need
> for your required range.
>
> If you have even more money, NiCads are the way to go. Not only are
> they capable of high performance but also, unless you REALLY abuse
> them, they're a lifetime purchase. You'd be able to move the pack
> from car to car.
>
> Of course, if you have more money than you know what to do with then
> there is, of course, the various Li chemistries.
>
> John
> ---
> John De Armond
> See my website for my current email address
> http://www.johngsbbq.com
> Cleveland, Occupied TN
> Don't let your schooling interfere with your education-Mark Twain
>
>
--- End Message ---
