EV Digest 3475
Topics covered in this issue include:
1) Re: Surplus NiCds - how to charge, test & recondition?
by "David Roden" <[EMAIL PROTECTED]>
2) Re: Hybrids that Plug IN !
by Brad Waddell <[EMAIL PROTECTED]>
3) help with EV motor data
by Jeff Shanab <[EMAIL PROTECTED]>
4) Re: Pre-EVent Report from Port Townsend
by Seth Murray <[EMAIL PROTECTED]>
5) Re: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!]
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
6) Re: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!]
by John Wayland <[EMAIL PROTECTED]>
7) Re: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!]
by John Wayland <[EMAIL PROTECTED]>
8) RE: help with EV motor data
by Roger Stockton <[EMAIL PROTECTED]>
9) Re: Beefing up contactors
by Martin Klingensmith <[EMAIL PROTECTED]>
10) T-Rex For Sale, Reduced Price
by Seth Murray <[EMAIL PROTECTED]>
11) Re: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!]
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
12) Re: Carbon sequestration
by "Mark Thomasson" <[EMAIL PROTECTED]>
13) Re: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!]
by David Dymaxion <[EMAIL PROTECTED]>
14) Re: help with EV motor data
by Lee Hart <[EMAIL PROTECTED]>
15) Re: Simple regulator question
by Lee Hart <[EMAIL PROTECTED]>
16) RE: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!]
by "Andre Blanchard" <[EMAIL PROTECTED]>
17) Re: T-Rex For Sale, Reduced Price
by Rich Rudman <[EMAIL PROTECTED]>
18) Re: Simple regulator question
by Christopher Zach <[EMAIL PROTECTED]>
--- Begin Message ---On 18 Apr 2004 at 22:09, John Foster wrote: > If they are low capacity, can I replace the caustic? ... is this a diy > activity? Maybe YOU can DIY it, but I'm not that [crazy][courageous][both]. Saft will rebuild them for you (for a price of course). But first follow their instructions for "reconditioning" in the manual. You might be surprised. > 5cells strapped together= 12V nominal. Five nicad cells (1.2 volts each nominal) make 6 volts. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Want to unsubscribe, stop the EV list mail while you're on vacation, or switch to digest mode? See http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 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 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = MPG of Ford's most fuel-efficient 2003 car: 36 MPG of Ford's 1912 Model T: 35 -- Harper's Index, Sept. 2003 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
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--- Begin Message --- This issue was covered on this list Dec 31, 2003 - the VAN is a controlled project and I believe is just for delivery companies. As usual, it's hard to get excited about something not available for PURCHASE.
see below.
brad
At 02:20 PM 04/18/2004 -0700, you wrote:I attended a seminar here in Seattle last week, called
"The New Apollo Energy Project" sponsored in part by US Representative Jay Inslee of Washington State, and attended by US Senator Maria Cantwell, and a dozen experts on climate, labor and industry, Energy, Oil, and politics, etc.
Any way, one gal from Washington DC mentioned that Dalmer/Chrysler was producing a "Plug-IN Hybrid" and as an avid reader of the EV Discussion List, and Local EAA Pres.. I was a bit embarrassed to say I had not heard of it yet...
So below are TWO very informative web sites for any one else who have not heard yet either...
All about Plug In Hybrids from CalCars: http://www.calcars.org/vehicles.html
and
from IEEE Spectrum On-Line "The SMART Hybrid" http://www.spectrum.ieee.org/WEBONLY/publicfeature/jan04/0104epow1.html --
Date: Wed, 31 Dec 2003 17:47:08 -0800 (PST)
From: Bruce EVangel Parmenter <[EMAIL PROTECTED]>
Subject: EVLN(DaimlerChrysler's plug-in hybrid van)-long
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
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EVLN(DaimlerChrysler's plug-in hybrid van)-long [The Internet Electric Vehicle List News. For Public EV informational purposes. Contact publication for reprint rights.] --- {EVangel} http://www.spectrum.ieee.org/WEBONLY/publicfeature/jan04/0104epow1.html The Smart Hybrid Flip a switch, and DaimlerChrysler's plug-in hybrid electric van will become an electric vehicle By Glenn Zorpette
Brad Waddell ** FLEXquarters.com LLC ** voice-mail/fax: 602-532-7019 Postal: 6965 El Camino Real Ste 105 #488 Carlsbad CA 92009 USA Plug-in to your QuickBooks data at www.qodbc.com
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--- Begin Message --- * You are using "Permanent Magnet Motor" equations.
I am? I was using the formula off of Uve's site of torque = k * amps ^ n where k and n are listed for the ADC 9 and 8 inchers : 9" is T = .0085 * I ^ 1.55
My motor book talks T = k I^2 in general. I hear BEMF reduces the current the motor can draw, I hear that the inductance changes the rate but not the amount
Please correct me, I hate to base a good deal of coding time on a wrong equation. Currently it goes thru a launch check that determins the max throttle allowed off the line without loosing traction based on maximum weight transfer fore and aft and lateraly then proceeds oversimply at that acceleration rate down the track
This makes a very fast run :-) So now I need to add in the BEMF component that reduces that capability I calculated the BEMF and subtracted from pack and now I have terminal voltage but where do I go from there?
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--- Begin Message --- someone please take lots of pictures for us east coasters!
seth
On Sunday, April 18, 2004, at 12:41 AM, Roderick Wilde wrote:
Howdy Folks
This is not Rod but Roy sending out a last minute promo from Rod's computer.
Rod, Rich, Father Time, and myself have been hammering much of the day to get the variety of EVs here ready to go for the big show tomorrow. There will be quite a few so come on down if you are in the area.
I am sure that I will miss a couple, but here is a list of what we expect to have there-
Gone Postal, Lightning Rod Street Rod, Lectro Rover, tire-meltin' golfcar, Rod's "Chick Magnet" NEV, two of Father Time's drag bikes and the "Blue Dragonfly" human/electric hybrid, 60mph Barstool, Silver Bullet 300ZX Drag Car, two Morad 1500 scooters, eGo scooter, EV Global eBike, and Rod's favorite truck, it just barely holds one adult and it says "700hp" on the hood, but it looks more like he stole it from a 3 year old boy :^D
I have spent the afternoon/evening custom fabricating various stuff including an aluminum bed for the golfcar, xtra large fuse holder for Gone Postal, and assisting the Madman (Rich) installing stuff and re-routing cabling in Gone Postal. In the morning, we will be washin' and cleanin' stuff and the usual mad rush to get it all together and to the EVent.
See Ya There!
Roy LeMeur
-- QUESTION INTERNAL COMBUSTION '72 Datsun 240Z Conversion http://users.wpi.edu/~sethm/
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--- Begin Message ---Is anyone using stepper motors to regulate brush timing and if so what advantage would there be for people who don't break things other than brute power? Is there any gain in efficiency when going high rpms? Whould it improve range? How is it implemented? Lawrence Rhodes.......
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--- Begin Message ---Hello to All, "[EMAIL PROTECTED]" wrote: > >Hey Bill, just curious...any reason you left White Zombie out of this > >part? > > I forgot you were running series/parallel. Ah hah! You've revealed yourself...with the myriad of posts I've done detailing the series/parallel setup, and with all my accounts of weekend drag racing all over this forum where I've talked extensively about the series/parallel setup, you must obviously must skip over, or God forbid, 'delete' my posts :-( > > As I recall, you had a Hawker battery pack when you made your > quickest runs. True, but again, also recently covered in one of my posts...did you miss that one, too? > This pack was a tad larger than your SVR pack, but much > smaller than your present pack of Excide batteries. Oops Bill, never had an SVR pack. Yes, the Hawkers at 378 lbs. were much lighter than the present 720 lb. pack of Orbitals...again, well covered in many of my posts. > The battery pack probably has the greatest single influence on performance. Agreed, and the real reason your bike ran in the 9's. With those amazingly powerful and light TMF Bolder cells, it wouldn't have made too much difference what motor (motors) you ran. Kudos to you, for doing all the before hand research and testing of the batteries...great job, and proof that doing the math 'before' does pay off. > Right now, your battery pack weighs way too much. You probably should go back to > SVRs or > > Hawkers, but run more of them, perhaps twice as many. This would allow you > to give the controller all the peak amps it wants, but would keep the > weight reasonably low. Twice as many of the 13.5 lb. Hawkers would put the pack at 756 lbs., a little heavier than what I am presently running, with about the same current potential, but, yes, at a higher voltage...would be interesting! Oh well, gotta go with my sponsorship and do what I can with what I've got to work with. Though the slower time of 13.7 (@216V) isn't as impressive as nearly 13 flat, it 'is' impressive to be able to drive back and forth to the track, and, to have an ~ 35-40 mile range, too. Bill, you got stop deleting those Waylaid posts! See Ya ...John 'Plasma Boy' Waylaid 'Plasma Boy Racing...we blow stuff up, so you don't have to!'
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--- Begin Message ---Hello to All, Roger Stockton wrote: > On Sunday, April 18, 2004 1:02 PM, John Wayland > [SMTP:[EMAIL PROTECTED] wrote: > > > Disclaimer...both Rich Brown and Damon Crocket are good friends of > > mine, both are smart guys, both built nice EVs based on RX7's, and > > both have their strong points. > > I've had the pleasure of meeting both of these guys, and watching > their cars run, and agree with you 100%. Yup, they and all the other racers are great fun, even when they're also your competitors. > > I don't mean to bash Damon's car, It's just a convenient example of a > car with a big (the biggest I've seen in a car yet!) single motor > that, for whatever reason, didn't live up to its potential. I've really enjoyed your posts back and forth with the Madman, and have enjoyed your thought process on the topic...Rudman likes it too, even though he doesn't come out and say so :-) > > Likewise, I am using Rich's car as an example of a dual-motored car > that does better than most would expect. That's an understatement! Turning low 14's @ 144V in a car with a 35-40 mile range, is very impressive. > It is convenient for > comparison's sake that both are RX7s, although Rich's is a heavier > later model while Damon's is the older, lighter version. Yes, it is a convenient comparison. > > I suppose my point all along was just that sticking a big motor in a > car doesn't guarantee it will perfrom well, anymore than sticking > multiple motors in one guarantees it will perform worse than a single > motor car. Total agreement, here. Rudman in fact, has warned me that it will take some trial and error, as well as carefully planned mods to match what the car presently does with the twin 8's, let alone surpass it. I of course, have my own ideas and designs, and these have worked well for me so far, but I'm really enjoying this fourth motor transplant idea...working with the Madman is always 'interesting'! I'm also very excited that Mr. Killowatt is behind my idea to do this, and I thank him for paving the way for the brush timing thing. > I look forward both to hearing how quick you get the twin 8's to go, > and how the monster GE responds to Madman prep (I hope that you guys > do throw us a dyno plot or two from the 'skunkworks' now an then...). I just received an email from a local Northwest Datsun Owners Association member, where he informed me that the tricked out Datsuns will be invading PIR for a Friday Night Street Drag shootout on the 30th, so I guess that will be this year's date for the return of my EV to the strip to see what it can do at 240V. I'll definitely be reporting the results. See Ya ...John 'Plasma Boy' Wayland 'Plasma Boy Racing...we blow stuff up, so you don't have to!'
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--- Begin Message ---On Monday, April 19, 2004 3:21 AM, Jeff Shanab [SMTP:[EMAIL PROTECTED] wrote: > * You are using "Permanent Magnet Motor" equations. > > I am? I was using the formula off of Uve's site of torque = k * > amps ^ n where k and n are listed for the ADC 9 and 8 inchers : > 9" is T = .0085 * I ^ 1.55 > > > My motor book talks T = k I^2 in general. Torque proportional to the square of current *only* applies to series wound motors (where the field and armature currents are equal), the general relationship is torque is proprtional to the product of armature field strength and stator field strength, with aramture field strength being proprtional to aramture current and stator field strength proprtional to stator field current (for wound fields; it is a constant for PM stators). > Please correct me, I hate to base a good deal of coding time on a > wrong equation. Don't base anything on the equations used by Uve's calculator. They are not motor equations but rather equations that happen to more or less fit the data points he had for one or more motors. How well they approximate the actual motor behaviour depends on how similar your motor's behaviour is to the motors he based his approximations on. The equations don't approximate the bahaviour of the motors in the calculator very well at low RPM/high torque or high RPM/low torque; they are really only useful to get a rough idea of performance at typical moderate operating conditions. Get a good motor book (if you haven't got one already), and you will be able to dig up the theoretical equations (like the torque proportional to the square of current) as a good starting point. Then dig up equations for the losses associated with a fan running at the motor shaft speed (these higher RPM losses are not included in motor text equations). If you surf the EV Parts site you will find plots for (IIRC) the ADC 9" with and without its internal fan; from this data you could derive the equation for actual fan losses for the ADC 9", and this would probably give a good approximation of the fan losses for other ADC models, though not necessarily for a Kostov or Prestolite. Then, get your hands on as much actual motor data as you can (again, the ADC plots from EV Parts are a good starting point), and start tweaking your equations until they produce results in agreement with reality (for instance, torque really ends up proportional to the 1.x power of current, not the 2nd power). Your equations still won't include terms to model the effects of armature reaction and saturation of the iron, but I haven't found a text yet that does much more than acknowledge that such things occur, nevermind actually attempt to model the behaviour. For a drag race simulator, perhaps you should bounce an email to Bill Dube asking for a copy of 'Strip Tune' (or do a web search for it); some time ago Bill mentioned this program as an excellent way to model drag strip performance and offered to send a copy to anyone who asked. Good luck, Roger.
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--- Begin Message --- I know several ceramic engineers if you would like me to ask for you.
-- -- Martin Klingensmith http://infoarchive.net/ http://nnytech.net/
David Chapman wrote:
>>
>> Thanks Mark and Lee,
>> Appreciate all the backround tech and suggestions. One last question on this
>> tho, what do you think is the best mechanical solid state insulator if
>> brittleness is not an issue? Glass? That was my best guess. Regards, David
>> Chapman.
Lee Hart wrote:
I'd probably use a ceramic. It won't burn or melt, and is a lot less likely to break than glass. But there are a zillion of them; you'd have to ask an application engineer at a ceramics manufacturer for some ideas.
The main reason I can see to shove something between the contacts is for something like an emergency disconnect switch. It doesn't operate often, but you want to be VERY sure it works when you *do* need it.
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--- Begin Message --- Hi list, I've reduced the price of my unused 1000A T-Rex motor controller to $1500. Email me off list for more info,
Seth
-- QUESTION INTERNAL COMBUSTION '72 Datsun 240Z Conversion http://users.wpi.edu/~sethm/
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--- Begin Message ---Are your procedures for brush implementation up for grabs or is is secret? Lawrence Rhodes... ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, April 18, 2004 5:10 PM Subject: Re: [Fwd: Re: Fw: Two 8" vs 1 9"...Zombie Gets a BIG motor!] > Please rember ALL I have been using movable brush rigging for over 2 years > now on a ge type motor.It does work,my time slips prove it.It is worth.6 > seconds(I know Bill its not much to you)John Force would kill for .6 sec.To the > person that said my car is no quicker than it was in Denver years ago at 10.20...it > has run 9.67 with the same type battery only 8 fewer on board.If I could have > hooked the track in Vegas a couple months ago it should have gone 9.40 > Bill Dube you know we had the same type and number of batteries in Vegas the > SVR.You had a PRO riding the KILL cycle and I had my cousin driving a dragster for > the 1st time in his life,The Current Eliminator still was 1.3 seconds quicker > and over 300lbs. heaver.(with a smaller controller)You Had Much More Power to > Weight Than My Car but still lost by a lot.The things I have done to my motor > circuit and continue to try are what makes The CE quicker...When I get the > new HOT batteries CE will blow its old record away. Being a betting man Bill > Dube I will bet the CE that you cannot beat the CE with the Killacycle with the > same amount and kind of battery,even with your bigger controller.I will make > it even more intresting Bill I will let you set my controller up 300 motor > amps less than your lighter bike controller,I just want to use my moving brush > assembly. Stay on coarse John You Will See a much quicker car with the moving > brushes. Dennis Kilowatt Berube 3700+ runs in an EV >
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--- Begin Message ---John, My guess is that no one knows how to build the device you describe below. Your design parameters: low power requirement, solid state/no maintenance, quiet, home buildable by anyone, and constant operation, fire and forget, etc,... sounds a lot like trees to me! Otherwise, seems easier to me to capture the CO2 at the power plant where its release is already concentrated. See the February 2004 National Geographic for a good report on this topic, also at http://magma.nationalgeographic.com/ngm/0402/feature5/index.html. Good luck, Mark T. ----- Original Message ----- From: "JD & Heather" <[EMAIL PROTECTED]> To: "EV List" <[EMAIL PROTECTED]> Sent: Saturday, April 17, 2004 11:31 PM Subject: OT: Carbon sequestration > I've put off asking the list this question because of how most > listers look upon OT posts but I've written to college professors, > chemists, even Scientific American with zero replies so with the recent > discussion of "cleaning the air" I just have to ask for input from the > list. This list is full of some of the smartest people I've met so here > goes. My sincere apologies to the list administrators but I'm desperate > for an answer to this. > As part of a corrective action concerning global warming, one of the > ideas (on a global scale) is to sequester CO2 underground, probably in > the very holes the oil was pumped out of. I have an idea of trying to > start some sort of "distributed seguestration" movement. Is it possible > to produce a low power device that would either remove CO and/or CO2 > from the air and pump it deep enough underground to prevent it from > getting back into the atmosphere or a similar device that would convert > atmospheric carbon into a durable solid that could then be buried? Yes, > I know trees already convert atmospheric carbon to a somewhat durable > solid but at best most woods only hang around for about a hundred years > before decomposing or being destroyed and there is still a lot of > disagreement about how much carbon a tree absorbs and for how long > during it's lifetime the tree will be a carbon sink before leveling off > to a slower rate of carbon absorption. > The design parameters (if that's the right term) I have for this > device would be low power requirement, as close to solid state/no > maintenence as you can get, quiet, home buildable by anyone, and > constant operation. Low power so it can be powered by a single solar > panel or small wind turbine. If you have to use grid power to do this, > which is probably made from coal, you might as well simply put the > electricity from the panel or turbine into the grid. Solid state/ low > maintenence for so it can be a "fire and forget" kind of machine till, > in the case of a device that converts gas CO to solid carbon, you need > to bury it. Which goes hand in hand with quiet, so you can put it in a > corner of your back yard and not worry about neighbors crying NIMBY or > put in a wilderness area away from people without disturbing the > wildlife. An since it would be a low power device it would probably need > to run constantly to do any appreciable amount of sequestration, a > battery pack with the solar panel. I'm sure the process of sequestering > or converting to solid would be devided into sub-processes and the > process with the lowest energy requirement could be done at night. > If a device like this could be built, I could see a movement > beginning where plans would be provided free on the internet and people > around the worl could build there own little carbon sinks in there own > backyard, then build more and spread them like Johnny Appleseeds (Johnny > Carbonsink?). Or, if the prospect of building them isn't doable by your > average layman, more technically capable individuals could build them > and sell them for the cost of parts. > I know this might be a really pie-in-the-sky kind of idea and I have > no idea if it can be done but I know of no other people who I could ask. > Thanks for any ideas or help. > > John David > > 98 Nissan Frontier (soon to be de-ICEed for one of Victor's AC systems) >
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--- Begin Message ---An idea for an infinitely variable series/parallel mix (view in Courier font): + + | | | controllerA | ___________| | / | | / | motor controllerB motor | / | |__________/ | | | controllerC | | | - - Turn on controllerA and controllerC, you have parallel. Turn on controllerB, you have series mode. Have a master controller (not shown) quickly go back and forth between controllerA+controllerC vs. controllerB, and you are switching between series and parallel. Now you wouldn't have the hole shifting from series to parallel, so you could get more area under the curve. ===== __________________________________ Do you Yahoo!? Yahoo! Photos: High-quality 4x6 digital prints for 25� http://photos.yahoo.com/ph/print_splash
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--- Begin Message ---Jeff Shanab wrote: > I was using the formula off of Uve's site of torque = k * amps ^ n > where k and n are listed for the ADC 9 and 8 inchers : 9" is T = > .0085 * I ^ 1.55 > > My motor book talks T = k I^2 in general. In theory, n=2 for a series motor. In practice, this is true only at low currents. As the current goes higher, magnetic saturation causes n to fall from 2 toward 1. Uve's site (over)simplifies this to n=1.55. If you want a simple equation that works for normal (i.e. not racing) conditions, Uve's is fine. But when you start applying 10x the rated current to a motor, its behaviour gets pretty far away from theory. -- "Never doubt that a small group of committed people can change the world. Indeed, it's the only thing that ever has!" -- Margaret Meade -- Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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--- Begin Message ---Christopher Zach wrote: > Quick question: How does a bypass regulator consisting of a zener > diode and a bulb work? This "simple" question turned out to be a lot of work! We all know what happens to AGM batteries with no regulators (they get out of balance and die early). To prevent this, I've used Rudman regulators for years. I've built 2 sets of my Hart zener-bulb regulators, which have been used for about a year. But, has anyone really documented exactly what is going on? I decided to gather some data and see. Charge a battery without a regulator, than with a Rudman, then with my regulator; and compare the results. Should be simple, right? WRONG! 1. The Test Subject -- Optima #22 I have an Optima Yellow Top that is a good "bad example". Put this battery in a series string, and you have trouble keeping it in balance. It is about 3 years old, and spent its first year in Rick Woodbury's Tango prototype, providing 1000-amp peak currents. Then its amphour capacity started dropping so it became the weakest link. On 10/19/02 we pulled it, and discovered that the cover seal had been broken (dropped into the pack, and its lid snagged on the battery next to it). Tested, it measured 24.27ah at 25 amps (about half of a new Optima). 10/20/02: I re-glued the cover, drilled holes above each cell, and added ounces of distilled water to bring it back up to the same weight as the rest of the cells. On successive charge-discharge cycles, its capacity rose; 30.69ah, 33.54ah, 36.31ah, 39.67ah, 40.1ah, 41.94ah, 42.08ah. This was essentially normal, and the battery was put back in service in another EV. But with a Rudman regulator, this battery was the first one to start bypassing current, and tended to go into thermal runaway the easiest; if the charger was left on too long, this battery's voltage would peak and start to fall again as the battery heated up. So, the battery was pulled, and used for the past 17 months as a "shop" battery. It sat idle 99% of the time, was occasionally discharged slightly, put on a float charger every few months, etc. 4/7/2004: I decided to use this battery for the regulator testing. Measured 12.45v no-load 4 months after charging. But under load, it delivered only 2.52ah! I put it on the cycler; capacity only slightly improved with each cycle. Here is a summary of the data. Charge cycle actually terminated at (V>14.92v and I<2a); discharge cycle actually terminated at V<10.5v at 22a. Positive amhours at end of charge is the "overcharge" put in beyond what the E-meter took to reset to "full" with CEF=99%. ;Time, Volts, AmpHrs, Amps, 4-7-2004, Optima #22 after 17-month rest 18:00:40, 12.45, 0,-.002 ; cycle#1 18:04:59, 14.89, .16, 2.3 ; +0.16ah charge 18:11:42, 12.20,-2.52,-23.4 ; -2.52ah discharge 18:12:45, 13.18,-2.14, 17.3 ; cycle#2 18:38:10, 14.87, .21, 2.267 ; +0.21ah charge 18:53:01, 12.05,-3.2,-25.77 ; -3.2ah discharge 18:54:00, 12.92,-2.8, 30.8 ; cycle#3 19:23:09, 14.88, .38, 2.04 ; +0.38ah charge 19:38:09, 10.57,-3.71,-22.39 ; -3.71ah discharge 19:39:02, 11.85,-3.71, 32.2 ; cycle#4 20:15:39, 14.92, .53, 1.809 ; +0.53ah charge 20:30:38, 10.55,-4.37,-22.33 ; -4.37ah discharge 20:31:20, 11.80,-4.37, 32.9 ; cycle#5 21:08:08, 14.88, .48, 1.957 ; +0.48ah charge 21:23:08, 10.99,-3.59,-23.29 ; -4.95ah discharge 21:26:47, 11.70,-4.95, 33.59 ; cycle#6 22:08:07, 14.92, .5, 1.893 ; +0.5ah charge 22:25:57, 10.46,-5.5,-20.7 ; -5.5ah discharge 22:25:58, 11.65,-5.5, 33.79 ; cycle#7 23:15:37, 14.95, .28, 1.764 ; +0.28ah charge 23:23:07, 11.84,-3.14,-25.05 ; -6.04ah discharge 4/8/04: Charged battery 24 hours with a 15v power supply with a 1.5 ohm resistor in series. 14:42:09, 14.15, 11.26, .74 ; cycle#8 14:42:17, 14.14, 11.27,-.039 ; +11.27ah charge 15:14:12, 10.50,-13.14,-4.09 ; -13.14ah discharge 4/9/04: The long, slow overcharge doubled the capacity! So, I charged the same way another 24 hours, did another discharge cycle, and got -18.55ah. 4/10/04: Did it again. This time, capacity only rose to -19.8ah. 4/11/04: Did it again. Capacity -21.2ah. I decided this is stable enough for testing regulators. Here are excerpts from the test data to show how this battery charges with NO regulator: 18:53:18, 10.48,-21.73,-.05 ; end of last discharge test 19:00:03, 11.55,-21.73, 4.15 ; charge with no regulator 19:00:04, 11.59,-21.73, 32.2 19:04:15, 12.98,-20.08, 22.90 19:19:15, 13.23,-14.82, 19.85 19:49:14, 13.68,-6.81, 13.02 20:19:14, 14.38,-2.31, 5.509 20:49:14, 14.82, 0, 2.234 ; E-meter resets to 'full' 21:09:01, 14.99, .61, 1.549 21:34:13, 15.13, 1.14, 1.117 21:49:13, 15.17, 1.4, 1.019 ; +1.4ah overcharge in 1 hour 22:04:13, 15.18, 1.64, .986 ; thermal walkaway begins after 1.25 hrs 22:19:13, 15.17, 1.89, 1.025 22:34:12, 15.16, 2.16, 1.119 22:49:12, 15.13, 2.45, 1.241 ; +2.45ah in 2 hours 23:19:13, 15.03, 3.16, 1.594 ; end charging manually In general, the voltage rises and the current falls as it charges. The E-meter resets to "full" when the battery is at 100% SOC (has actually put in 101% of the amphours removed, and the battery would deliver the same amhour capacity as the last cycle if immediately discharge-tested). Without a regulator, the voltage after reach full charge soars, reaching 15.18v at 0.986a in this case. A new Optima's voltage would have kept right on climbing at this point, and could easily reach 16v! But this battery wants to 'walk away' (like thermal runaway, but slower). After 1.25 hours, its voltage starts to fall, and the current increases. The battery is gassing, and heating up. If allowed, the current will rise past 2 amps, and the battery will start venting. Notice how many amphours in excess of what is needed to reach full charge were put in at the 1-hour and 2-hour points; +1.4ah at 1 hour, +2.45ah at 2 hours. This is your "equalization" current. This battery doesn't need equalization because of the preceeding long slow charge cycles, so this excess charging is what is causing the unnecessary gassing and thermal runaway. I did two tests of each case; no regulator, with Rudman regulator, and my zener-lamp regulators. The Rudman regulator was one of his Mark-1 with the on-board 7.5 ohm resistor (which I had to put a fan on to keep it cool). I set it to turn on at 14.9v and 15.0v with a pure DC power supply for the two tests. My Hart regulators were a 6.2v 5w zener, 6.8v 5w zener, and PR2 lamp in series for the first test, and with a 10 ohm resistor added across the lamp for the second test. Here is a summary: Rudman reg. Hart regulator no regulator @14.8v @14.9v 13v+PR2 +10ohom ----------------- -------------- -------------- -------------- 1 hr after reset 1.4 ah 1.45ah 1.24ah 1.41ah 2.09ah 1.45ah 2 hrs after reset 2.45ah 2.49ah 1.96ah 2.26ah 2.85ah 2.49ah thermal walkaway 1.25hr 2.25hr 2.85hr 2.1 hr 3.25hr 2.25hr max battery voltage 15.18v 15.14v 14.90v 15.0v 15.18v 15.07v max shunt current 0 0 1.34a 0.94a 0.38a 0.38a min charge current 0.99a 1.19a 0.64a 0.87a 0.66a 0.89a This data suggests that the situation is a lot more complicated that people think! 1. Notice that regulators hardly make any difference in the amphours actually put into a battery during the overcharge. They lower the voltage, but the battery just adjusts itself to charge at the same current regardless of the reduced voltage. This sort of makes sense; a nearly fully-charged battery only "accepts" current at a low rate. It is acting somewhat like a constant-current sink. Applying more voltage doesn't increase the acceptance current; it just makes more gassing and heating. 2. Regulators *do* make it take longer for the battery to go into thermal runaway. That's a sign that they are working to reduce overcharging. But, the effect is much weaker than I thought. A large change in voltage has a small effect on battery current. 3. Even though the Rudman regulator bypasses more current, and holds the battery voltage down better, it is less effective than the simple zener-lamp regulator at preventing thermal runaway. My guess is that this is because the Rudman does nothing until the battery is already in overcharge, and then tries to do too much. Kind of like driving at full speed until just before the traffic light, then jamming on the brakes hard. The zener-lamp regulator starts bypassing current much earlier. This seems to help "ease" up to full charge at a lower current. Maybe there is some overcharging going on even when the battery is well below the Rudman threshold, which the zener-lamp regulator is limiting. For reference, here is the current-voltage relationship for my 6.2v + 6.8v + (PR2 | 10 ohm) regulator: 12.3v 0.2ma 13.07v 1ma 13.33v 25ma 13.92v 100ma 14.08v 250ma 14.58v 310ma 14.79v 340ma 15.01v 375ma 15.07v 382ma -- "Never doubt that a small group of committed people can change the world. Indeed, it's the only thing that ever has!" -- Margaret Meade -- Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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--- Begin Message ---Why limit the conversation to just two small motors and series/parallel switch verses one big motor. :) How about one big motor with series/parallel switching on the field coils. You could have two switch points, start with all four coils in series, switch to a parallel connection of two series coils, and last to all four in parallel. You would likely need custom wound coils, bigger wire so that each coil can handle full current. And maybe a larger case so there is room. Or maybe a single large motor with a compound field so that you can have a continuous adjustment of the motor's volts per rev constant. Thanks, Andre' B. Clear Lake Wis.
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--- Begin Message ---Seth Murray wrote: > > Hi list, I've reduced the price of my unused 1000A T-Rex motor > controller to $1500. Email me off list for more info, > > Seth > > -- > QUESTION INTERNAL COMBUSTION > '72 Datsun 240Z Conversion > http://users.wpi.edu/~sethm/ This is quite a Deal folks!! -- Rich Rudman Manzanita Micro www.manzanitamicro.com 1-360-297-7383,Cell 1-360-620-6266
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--- Begin Message --- This is very interesting, but what I think is missing is what I'll call the "drag along" factor.
Say you have three batteries. Two are 50% charged, and one is 90%. Maybe the third one has lousy capacity.
So you charge away at 20 amps till the voltage tapers off to say 45 volts at full charge. Ok.
Battery 1 hits 15 volts (charged), but batteries 2 and 3 are still at 13 volts. So the charger keeps rolling in current, trying to bring the pack to full power. The 20 amps stays
Now battery 1 is charged, but still has 20 amps rolling thru it. So the voltage on this battery goes up. Since the lower two are still sitting at 13 volts, it could go up to 18 volts and the charger would still see a pack voltage of 44 volts and still keep rolling on the current. Now you have a battery that is pulling 18 volts, 20 amps, and is in the uncomfortable position of being a massive CC wreck.
How can a regulator help here? Unless the reg could tell the charger to back off, the reg would have to bypass the full 20 amp difference between the battery's 15 volts and the 18+ volts that the assembly is being asked to supply.
If only there were a way to essentially say "Ok, this battery will stay at 15 volts now." then the other batteries could come up to steam.
Chris
Lee Hart wrote:Christopher Zach wrote:
Quick question: How does a bypass regulator consisting of a zener diode and a bulb work?
This "simple" question turned out to be a lot of work!
We all know what happens to AGM batteries with no regulators (they get out of balance and die early). To prevent this, I've used Rudman regulators for years. I've built 2 sets of my Hart zener-bulb regulators, which have been used for about a year.
But, has anyone really documented exactly what is going on? I decided to gather some data and see. Charge a battery without a regulator, than with a Rudman, then with my regulator; and compare the results. Should be simple, right? WRONG!
1. The Test Subject -- Optima #22
I have an Optima Yellow Top that is a good "bad example". Put this battery in a series string, and you have trouble keeping it in balance.
It is about 3 years old, and spent its first year in Rick Woodbury's Tango prototype, providing 1000-amp peak currents. Then its amphour capacity started dropping so it became the weakest link.
On 10/19/02 we pulled it, and discovered that the cover seal had been broken (dropped into the pack, and its lid snagged on the battery next to it). Tested, it measured 24.27ah at 25 amps (about half of a new Optima).
10/20/02: I re-glued the cover, drilled holes above each cell, and added ounces of distilled water to bring it back up to the same weight as the rest of the cells. On successive charge-discharge cycles, its capacity rose; 30.69ah, 33.54ah, 36.31ah, 39.67ah, 40.1ah, 41.94ah, 42.08ah.
This was essentially normal, and the battery was put back in service in another EV. But with a Rudman regulator, this battery was the first one to start bypassing current, and tended to go into thermal runaway the easiest; if the charger was left on too long, this battery's voltage would peak and start to fall again as the battery heated up.
So, the battery was pulled, and used for the past 17 months as a "shop" battery. It sat idle 99% of the time, was occasionally discharged slightly, put on a float charger every few months, etc.
4/7/2004: I decided to use this battery for the regulator testing. Measured 12.45v no-load 4 months after charging. But under load, it delivered only 2.52ah! I put it on the cycler; capacity only slightly improved with each cycle. Here is a summary of the data. Charge cycle actually terminated at (V>14.92v and I<2a); discharge cycle actually terminated at V<10.5v at 22a. Positive amhours at end of charge is the "overcharge" put in beyond what the E-meter took to reset to "full" with CEF=99%.
;Time, Volts, AmpHrs, Amps, 4-7-2004, Optima #22 after 17-month rest 18:00:40, 12.45, 0,-.002 ; cycle#1 18:04:59, 14.89, .16, 2.3 ; +0.16ah charge 18:11:42, 12.20,-2.52,-23.4 ; -2.52ah discharge 18:12:45, 13.18,-2.14, 17.3 ; cycle#2 18:38:10, 14.87, .21, 2.267 ; +0.21ah charge 18:53:01, 12.05,-3.2,-25.77 ; -3.2ah discharge 18:54:00, 12.92,-2.8, 30.8 ; cycle#3 19:23:09, 14.88, .38, 2.04 ; +0.38ah charge 19:38:09, 10.57,-3.71,-22.39 ; -3.71ah discharge 19:39:02, 11.85,-3.71, 32.2 ; cycle#4 20:15:39, 14.92, .53, 1.809 ; +0.53ah charge 20:30:38, 10.55,-4.37,-22.33 ; -4.37ah discharge 20:31:20, 11.80,-4.37, 32.9 ; cycle#5 21:08:08, 14.88, .48, 1.957 ; +0.48ah charge 21:23:08, 10.99,-3.59,-23.29 ; -4.95ah discharge 21:26:47, 11.70,-4.95, 33.59 ; cycle#6 22:08:07, 14.92, .5, 1.893 ; +0.5ah charge 22:25:57, 10.46,-5.5,-20.7 ; -5.5ah discharge 22:25:58, 11.65,-5.5, 33.79 ; cycle#7 23:15:37, 14.95, .28, 1.764 ; +0.28ah charge 23:23:07, 11.84,-3.14,-25.05 ; -6.04ah discharge
4/8/04: Charged battery 24 hours with a 15v power supply with a 1.5 ohm resistor in series.
14:42:09, 14.15, 11.26, .74 ; cycle#8 14:42:17, 14.14, 11.27,-.039 ; +11.27ah charge 15:14:12, 10.50,-13.14,-4.09 ; -13.14ah discharge
4/9/04: The long, slow overcharge doubled the capacity! So, I charged the same way another 24 hours, did another discharge cycle, and got -18.55ah.
4/10/04: Did it again. This time, capacity only rose to -19.8ah.
4/11/04: Did it again. Capacity -21.2ah.
I decided this is stable enough for testing regulators. Here are excerpts from the test data to show how this battery charges with NO regulator:
18:53:18, 10.48,-21.73,-.05 ; end of last discharge test 19:00:03, 11.55,-21.73, 4.15 ; charge with no regulator 19:00:04, 11.59,-21.73, 32.2 19:04:15, 12.98,-20.08, 22.90 19:19:15, 13.23,-14.82, 19.85 19:49:14, 13.68,-6.81, 13.02 20:19:14, 14.38,-2.31, 5.509 20:49:14, 14.82, 0, 2.234 ; E-meter resets to 'full' 21:09:01, 14.99, .61, 1.549 21:34:13, 15.13, 1.14, 1.117 21:49:13, 15.17, 1.4, 1.019 ; +1.4ah overcharge in 1 hour 22:04:13, 15.18, 1.64, .986 ; thermal walkaway begins after 1.25 hrs 22:19:13, 15.17, 1.89, 1.025 22:34:12, 15.16, 2.16, 1.119 22:49:12, 15.13, 2.45, 1.241 ; +2.45ah in 2 hours 23:19:13, 15.03, 3.16, 1.594 ; end charging manually
In general, the voltage rises and the current falls as it charges. The E-meter resets to "full" when the battery is at 100% SOC (has actually put in 101% of the amphours removed, and the battery would deliver the same amhour capacity as the last cycle if immediately discharge-tested).
Without a regulator, the voltage after reach full charge soars, reaching 15.18v at 0.986a in this case. A new Optima's voltage would have kept right on climbing at this point, and could easily reach 16v!
But this battery wants to 'walk away' (like thermal runaway, but slower). After 1.25 hours, its voltage starts to fall, and the current increases. The battery is gassing, and heating up. If allowed, the current will rise past 2 amps, and the battery will start venting.
Notice how many amphours in excess of what is needed to reach full charge were put in at the 1-hour and 2-hour points; +1.4ah at 1 hour, +2.45ah at 2 hours. This is your "equalization" current. This battery doesn't need equalization because of the preceeding long slow charge cycles, so this excess charging is what is causing the unnecessary gassing and thermal runaway.
I did two tests of each case; no regulator, with Rudman regulator, and my zener-lamp regulators. The Rudman regulator was one of his Mark-1 with the on-board 7.5 ohm resistor (which I had to put a fan on to keep it cool). I set it to turn on at 14.9v and 15.0v with a pure DC power supply for the two tests. My Hart regulators were a 6.2v 5w zener, 6.8v 5w zener, and PR2 lamp in series for the first test, and with a 10 ohm resistor added across the lamp for the second test. Here is a summary:
Rudman reg. Hart regulator no regulator @14.8v @14.9v 13v+PR2 +10ohom ----------------- -------------- -------------- -------------- 1 hr after reset 1.4 ah 1.45ah 1.24ah 1.41ah 2.09ah 1.45ah 2 hrs after reset 2.45ah 2.49ah 1.96ah 2.26ah 2.85ah 2.49ah thermal walkaway 1.25hr 2.25hr 2.85hr 2.1 hr 3.25hr 2.25hr max battery voltage 15.18v 15.14v 14.90v 15.0v 15.18v 15.07v max shunt current 0 0 1.34a 0.94a 0.38a 0.38a min charge current 0.99a 1.19a 0.64a 0.87a 0.66a 0.89a
This data suggests that the situation is a lot more complicated that people think!
1. Notice that regulators hardly make any difference in the amphours actually put into a battery during the overcharge. They lower the voltage, but the battery just adjusts itself to charge at the same current regardless of the reduced voltage.
This sort of makes sense; a nearly fully-charged battery only "accepts" current at a low rate. It is acting somewhat like a constant-current sink. Applying more voltage doesn't increase the acceptance current; it just makes more gassing and heating.
2. Regulators *do* make it take longer for the battery to go into thermal runaway. That's a sign that they are working to reduce overcharging.
But, the effect is much weaker than I thought. A large change in voltage has a small effect on battery current.
3. Even though the Rudman regulator bypasses more current, and holds the battery voltage down better, it is less effective than the simple zener-lamp regulator at preventing thermal runaway.
My guess is that this is because the Rudman does nothing until the battery is already in overcharge, and then tries to do too much. Kind of like driving at full speed until just before the traffic light, then jamming on the brakes hard.
The zener-lamp regulator starts bypassing current much earlier. This seems to help "ease" up to full charge at a lower current. Maybe there is some overcharging going on even when the battery is well below the Rudman threshold, which the zener-lamp regulator is limiting.
For reference, here is the current-voltage relationship for my 6.2v + 6.8v + (PR2 | 10 ohm) regulator:
12.3v 0.2ma 13.07v 1ma 13.33v 25ma 13.92v 100ma 14.08v 250ma 14.58v 310ma 14.79v 340ma 15.01v 375ma 15.07v 382ma -- "Never doubt that a small group of committed people can change the world. Indeed, it's the only thing that ever has!" -- Margaret Meade -- Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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