EV Digest 5183
Topics covered in this issue include:
1) RE: RE : critical mass-battery weight vs amp hour ratings
by "Myles Twete" <[EMAIL PROTECTED]>
2) Re: Why not more AC conversions vs DC conversions...
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
3) RE : critical mass-battery weight vs amp hour ratings
by [EMAIL PROTECTED]
4) RE: RE : critical mass-battery weight vs amp hour ratings
by "Roger Stockton" <[EMAIL PROTECTED]>
5) Re: A trip to the referee station
by [EMAIL PROTECTED]
6) Re: Why not more AC conversions vs DC conversions...
by Neon John <[EMAIL PROTECTED]>
7) Re: Why not more AC conversions vs DC conversions...
by Neon John <[EMAIL PROTECTED]>
8) Re: Why not more AC conversions vs DC conversions...
by Jim Coate <[EMAIL PROTECTED]>
9) RE: Why not more AC conversions vs DC conversions...
by Jeff Shanab <[EMAIL PROTECTED]>
10) Re: Driving 45 mph on the freeway?
by Ken Trough <[EMAIL PROTECTED]>
11) Re: Why not more AC conversions vs DC conversions...
by Ralph Merwin <[EMAIL PROTECTED]>
12) Re: Why not more AC conversions vs DC conversions...
by Ryan Stotts <[EMAIL PROTECTED]>
13) Milburn Light Electric (was: RE: Why not more AC conversions vs DC
conversions...)
by "Myles Twete" <[EMAIL PROTECTED]>
14) Re: Why not more AC conversions vs DC conversions...
by Electro Automotive <[EMAIL PROTECTED]>
15) Re: Why not more AC conversions vs DC conversions...
by Ryan Stotts <[EMAIL PROTECTED]>
16) Re: Why not more AC conversions vs DC conversions...
by Christopher Zach <[EMAIL PROTECTED]>
17) RE: contactor weld/arc ... OT vid clip
by James Massey <[EMAIL PROTECTED]>
18) Re: Battery Desulfators (Was: Flooded Battery Questions From A Newbie)
by paul wiley <[EMAIL PROTECTED]>
19) Re: Hawker AeroBattery 'correct' Info
by paul wiley <[EMAIL PROTECTED]>
20) Re: looking for VW bug kit
by Jimmy Argon <[EMAIL PROTECTED]>
21) Re: Why not more AC conversions vs DC conversions...
by Ralph Merwin <[EMAIL PROTECTED]>
22) Re: looking for VW bug kit
by "jmygann" <[EMAIL PROTECTED]>
23) Sydney AEVA open day
by "Claudio Natoli" <[EMAIL PROTECTED]>
24) RE: C?
by Cor van de Water <[EMAIL PROTECTED]>
25) Re: C?
by "Evan Tuer" <[EMAIL PROTECTED]>
26) Re: Why not more AC conversions vs DC conversions...
by "Andre' Blanchard" <[EMAIL PROTECTED]>
27) Tire smoke.
by "STEVE CLUNN" <[EMAIL PROTECTED]>
28) Re: Driving 45 mph on the freeway?
by "STEVE CLUNN" <[EMAIL PROTECTED]>
--- Begin Message ---> The drawback with gels is that they can't handle the sort of current > that AGMs do, but still cost significantly more than floodeds. If you It depends on how much current you need of course. A comparison: 12v Hawker Genesis AGM 70ah batteries cost over $220 12v Powersonic 100ah gel cells cost around $110 6v T-105s at 225ah run about $75 these days (at best) Under 50amp load, Hawker and the Powersonic AGM have about 50ah capacity T-105 probably about 170ah So, 12v Hawker Genesis 70ah at 50amps: 36.7cents/wh 12v Powersonic gel 100ah at 50amps: 18.3c/wh 6v Flooded T-105 225ah at 50amps: 7.4c/wh In these terms, the gel cell is 2.5x more costly than flooded. The Hawker would be over 5x more costly. But considering the cycle life differences, it may well be that the gel is actually cheaper in terms of $/wh/cycle for non-high discharge rate EVs. I'm certainly giving it some thought since I drive slow EVs... Anyone know anything about the WERKER AGM batteries being sold at Batteries Plus? I'm told that some of their models are actually rebadged Hawkers. The thing that peaks my interest is that as with the gelcells, the cost is 1/2 of what a similar capacity AGM is----something like $120 for the 100ah version---maybe it's a gelcell... -Myles Twete, Portland, Or. Steam Boat: http://www.pcez.com/~artemis/NWSSBoly.htm Steam Car: http://www.pcez.com/~artemis/NWSSALoco-t.htm Electric Boat: http://www.austinev.org/evalbum/492.html Electric Car: 1921 Milburn Light Electric: http://milburn.us/myles_twete1921.htm<<attachment: winmail.dat>>
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--- Begin Message --- Yes it's a money thing. Pound for pound DC systems are more cost effective. LR>........... ----- Original Message ----- From: "Joel Hacker" <[EMAIL PROTECTED]>To: <ev@listproc.sjsu.edu> Sent: Thursday, February 16, 2006 3:16 AM Subject: Why not more AC conversions vs DC conversions...Hey mabye this is another one of those dumb questions where I need slapped upside the head, but everything I read recently speaks to how more efficient AC motors because they don't need the series windings in the armature (rotor) and operate as an induction motor. 1. Is this right? 2. Are they more expensive? Any ideas as to why DC systems with PWM, and series wound motors (especially the Advanced DC ones) are so popular for conversions?
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--- Begin Message ---<<< A comparison: 12v Hawker Genesis AGM 70ah batteries cost over $220 12v Powersonic 100ah gel cells cost around $110 6v T-105s at 225ah run about $75 these days (at best) Under 50amp load, Hawker and the Powersonic AGM have about 50ah capacity T-105 probably about 170ah >>> If you believe the specs (http://battservice.com/store/itemub121100.html - weight iswrong, it's more like 84lbs), this $100 battery supplies 80A for 1hr (comments, Cor?)
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--- Begin Message ---Myles Twete wrote: > It depends on how much current you need of course. Right; this is what I noted. > A comparison: > 12v Hawker Genesis AGM 70ah batteries cost over $220 > 12v Powersonic 100ah gel cells cost around $110 > 6v T-105s at 225ah run about $75 these days (at best) > > Under 50amp load, > Hawker and the Powersonic AGM have about 50ah capacity > T-105 probably about 170ah Of course, you are wasting your money buying a 70Ah Hawker if your discharge needs are as modest as 50A. The whole point of Optimas, Hawkers, and Orbitals is their superiority over other AGMs in coping with high (extremely high) discharge currents. If you only need a palrty 50A, then you have many more choices available than just these "cream of the crop" selections... you are paying a premium for that high discharge current capability, especially in the case of Hawkers, so don't waste your money on a feature you don't need or can't use. At these modest discharge rates (~C/2), there are cheaper AGM choices (e.g. Concorde, and even some of the Chinese AGMs, etc.) that make for a fairer comparison to the likes of the Powersonic gel. Or, compare the cost of a quality gel such as the DEKA Dominator.... > But considering the cycle life differences, it may well be > that the gel is actually cheaper in terms of $/wh/cycle for > non-high discharge rate EVs. I'm certainly giving it some > thought since I drive slow EVs... This may be true, but the comparison you are using is inherently flawed because you compare an expensive AGM that is specifically well-suited to high-rate discharge to an average gel instead of considering the cost of a cheaper AGM that is just as well-suited to low rate discharge. If one is willing to compare and buy batteries based on lifetime energy throughput ($/total kWh of service), then other chemistries such as LiIon, NiCd, and NiMH can often offer surprising advantages over traditional lead acid despite the much higher initial cost. For hobbiest EVers, battery cost usually largely means the initial battery cost, not cost per mile or kWh of service. > Anyone know anything about the WERKER AGM batteries being > sold at Batteries Plus? I'm told that some of their models > are actually rebadged Hawkers. The thing that peaks my > interest is that as with the gelcells, the cost is 1/2 of > what a similar capacity AGM is----something like $120 for the > 100ah version---maybe it's a gelcell... I'm not aware of a 100Ah Hawker that WERKER could have rebadged. My concern here would be whether a rebadged Hawker offers the same performance/quality as the "name brand" version, or if they are rebadged after being found substandard in some way. It may be less of an issue if your application doesn't push the battery limits at all, but in that case you may still be better off looking at some of the cheaper (but good quality) name brands, like Concorde, that are fine for low rate discharge applications. One other thing to bear in mind is that AGMs can usually be recharged more quickly than gels, so even if your application discharges at a modest rate you may want to consider AGMs if you want to minimise recharge time. Cheers, Roger.
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--- Begin Message ---<<< I drive freeways in California at 45mph. I have never had a problem going 45mph. I stay in the slow lane and mind my business. 45mph is the legal minimum on California freeways. I have had the occasional idiot tailgate me or flash me when I go the speed limit in the slow lane It's something I just don't understand. Just keep your eyes forward and don't react. Going slow on the freeway is the compromise. Lawrence Rhodes....... >>> Hate to be a ditto-head, but ditto! Until the Ranger started showing the warning wrench, I did the work commute between 50 and 55mph, as low as 45mph when the winds kick up. Hope to address the service issue soon, but for now it's the around-town drive.
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--- Begin Message ---Now that's a cool looking E-car. Do you drive it much? John On Thu, 16 Feb 2006 11:34:11 -0800, "Myles Twete" <[EMAIL PROTECTED]> wrote: >> In my experience, a Solectria Force uses about 120-160 Wh per >> mile from the battery in gentle suburban driving, with speeds not >exceeding >> 45mph. > >And with the 96v of Hawkers (8 batts) in my tiller-shifter, tiller-steered >1921 Milburn Light Electric I guess I'm in good company at under 45mph >speeds (my top speed hit was a scary 40mph): > >wh/mile(30mph) ~ 95v * 40a / 30mph ~ 127wh/mi >wh/mile(35mph) ~ 90v * 60a / 35mph ~ 154wh/mi > >We've come a long way since 1921... > >-Myles Twete >1921 Milburn Light Electric: http://milburn.us/myles_twete1921.htm > --- John De Armond See my website for my current email address http://www.johngsbbq.com Cleveland, Occupied TN A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
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--- Begin Message ---On Thu, 16 Feb 2006 14:15:46 -0500, "David Roden" <[EMAIL PROTECTED]> wrote: >On 16 Feb 2006 at 13:45, Neon John wrote: > >> That is completely irrelevant. Solectria did it with high voltage and >> low current. > >Not at all. Did you read what Sherry wrote? It used 30a at 156v. That's >no higher voltage than a typical DC conversion. Power consumption at that >current would be 4.7kW. I missed the 156 volts. > >> What matters is the watts drawn and the WH per mile. > >In my experience, a Solectria Force uses about 120-160 Wh per mile from the >battery in gentle suburban driving, with speeds not exceeding 45mph. And >that's not just me; many dozens of Force owners report that level of energy >usage. Typically, unless you have a lead foot, the amp hour counter ticks >about once per mile. > >In all fairness I should point out that these are probably some of the most >highly optimized conversions ever done. Solectria junked the stock trans >and replaced it with a very light, low friction, aluminum-cased transaxle. >There are other modifications to reduce drag and rolling resistance. It's >not just the drive system, although that's certainly designed with >efficiency as a primary consideration. Now leave everything exactly the same except yank out that AC motor and install a DC one capable of similar RPM range. The difference will be miniscule. > >Ah, nothing like a good AC vs. DC flame war to get things heated up on a >cool February day. <g> Nah, not a chance. John --- John De Armond See my website for my current email address http://www.johngsbbq.com Cleveland, Occupied TN A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
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--- Begin Message ---Huh? I wish my Force did that!Driving in "economy" mode limits the battery current to 50 amps, and seems to be good for local flat roads up to 30-40 mph. And will achieve the ~1 Ahr per 1 mile goal.. "Normal" mode sets the limit to 100 amps, and is okay for flat roads up to 50-60 mph. Acceleration in both cases is mediocre... using "power" mode give 150+ amps for somewhat more respectable acceleration.However, on the steep hills even in "power" mode it can only maintain 30-35 mph... these are rural roads where folks typically go 50 or 60 mph. Driving through these hills, even with regen to help, results in closer to 2 Ahr/mile consumed.And yes, I have been meaning to figure out what controller/motor combo are in the car and if with more/different batteries could get more power out of it.Electro Automotive wrote:We did some test driving up here in the mountains with a Solectria Force, 156V, and the MOST current we ever pulled out of the battery pack was ~30A. DC systems are usually set up to meaure motor current, not battery current, so there is some difference, but that seems much more than "slight" to me. It surprised me at the time, as I did not expect that much difference.-- Jim Coate 1970's Elec-Trak's 1997 Solectria Force 1998 Chevy S-10 NiMH BEV 1997 Chevy S-10 NGV Bi-Fuel http://www.eeevee.com
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--- Begin Message ---Andre said > " No reason they could not be built in EV sizes with RPM's in the 10,000 to 12,000 range. Actually there may be a good reason why not, Jim can aswer this better. The force excerted on the comm bars goes up with square of the comm diameter and the number of bars and size of these bars are in conflict for high rpm and high amps. So while it is easy to build a small diameter high rpm commutated motor, it is impractical to build a large diameter high rpm motor. I think that we have gone backwards in recent years. The old steel comms were much stronger but have all but been replaced with "molded mica comms" , It doesn't seem to take much to blow them up :-( One other thing is that the brush surface speed goes up and there is a limit where the film won't form and the brushes grind to dust. I have thought of other ways of doing a commutator for high rpm the torpedo drone motors are a good example and so are the face type used in fuel pumps(kinda scary to find out fuelpumps in our cars are commutator motors until it is understood that it is sparkless because it is carbon-carbon.) Imagine if you were to invert the whole series motor. The wedges would be stationary and their section gets wider from point of contact, not skinnyier. The rotating plate with the brushes on it comes out to slip rings that can handle rpm well and some large high silver brushes since there is little to no sparking on them. The plate would look like a distributer and perhaps could have weights and springs for rpm dependent advance! The outside windings are the armature and perhaps we could put caps between the now stationary segments to limit sparking, but the sparking is needed or we don't get the needed film. I don't know how this would effect cooling of the motor. The "field" in the center would be small and simpler, so it could be on a hollow shaft with air running thru it? Maybe then we can crank out some rpms. This would be a lot of work and I am sure people would see that this is not really a step forward. more of a sideways step. Would it be worth it? I think no How about 6-step on an induction motor. Would that be the "ford" Induction motor? Simpler(cheaper?) control on AC wound motor, regen and "fail on" safe.
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--- Begin Message ---I drive freeways in California at 45mph.I strongly advocate personal choice and I absolutely support Lawrence's right to do this. While I am very glad to hear he stays in the right lane and has not had problems to date, going 45 mph on the freeway in California is very dangerous behavior, in my opinion.Of course this doesn't matter so much during heavy stop and go rush hour traffic, but studies have shown that vehicles travelling well outside of the average speed of traffic (either much faster or much slower) are involved in many accidents.According to recent data compiled by the National Highway Traffic Safety Administration, while "inattentive drivers" pose the single greatest risk to your health on the road, in California 32% of all traffic related fatalities are speed related crashes, and many of these (~40%) occur on Interstate and non-interstate roads where the speed limit is posted at 55 mph or higher.California freeways have one of the highest average speeds for a traffic dense environment of anywhere I have driven in the US.I am not being critical of anyone for making this choice, rather just providing a friendly word of caution for those considering this in the future.-Ken Trough V is for Voltage http://visforvoltage.com AIM/YM - ktrough FAX/voice message - 206-339-VOLT (8658)
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--- Begin Message ---Christopher Zach writes: > > The Prizm can easily keep up with traffic and seems to run around > 280-300w/mile at 60mph highway cruise. My Prizm gets about the same: 260-300wh/mile, depending on traffic. This is with a 156v pack of Optima buddy pairs, a 9" ADC motor and a Zilla Z1K controller, and I got about the same when the car had a 120v pack of SAFT NiCads and a DCP-600 controller. Ralph
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--- Begin Message ---Jeff Shanab wrote: > One other thing is that the brush surface speed goes up and there is a > limit where the film won't form and the brushes grind to dust. I was unaware of that. Information like that is tremendously valuable. For some reason though, it tends not to be common knowledge or even written anywhere. Thanks for sharing.
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--- Begin Message ---John asked: > >1921 Milburn Light Electric: http://milburn.us/myles_twete1921.htm > Now that's a cool looking E-car. Do you drive it much? Nope...only to club events since it's registered as an antique vehicle---took it to Wayland's EV breakfast and later in the week to the OEVA meeting. In between times I drove it down to the Willamette River in Milwaukie and up to the top of Mt. Tabor in town...now she rests. Everyone on the street loves the thing! It's pretty scary-weird driving a vehicle with no seatbelts, no brake lights or turn signals, poor brake force and tiller steering and speed control. Finally, it needs wood work, upholstery, paint, etc...something I'd like to get going this year. It is cute, but it'll be a lot cooler when it's detailed and finished. I need to visit other Milburn owners and see how it should look when complete...don't want to cut too many corners. It could be that I'm the only antique EV owner who is running with Hawkers...I did visit a guy in Florida who has a couple old Detroit Electrics which have 6v Optimas in them though. Drum contact speed control is kind of a trip---but it's not the only scary thing electrically on these beasts. The plug braking coil being located under the carriage floorboards and near the controller cables makes for a nice opportunity for melting or burning things if you use plug braking for more than a few seconds at any decent speed. So I've learned a few things. Currently, I'm building a second charger for it. I have a Vicor Megapac configured as a 120v/13amp CI/CV charger that works well. The second one I'm building should come close to that. Later I get to figure how to make the two of them work together to deliver whatever current keeps the AC circuit from blowing and then shut down the supplies after the batteries reach 120v (or after a float time). I don't want the fan running overnight or have the batteries sit with 120v on them until I arrive days after. So I should end up with a 0-25amp charger which will operate off of 110v or 220vac, with 99% PFC, 85% efficiency and take very little space (something like 5x7x14" each). Overall cost well under $200---I cheated since I have a pile of 48v/150w Vicor DC/DC converters I got at a good price. The Vicor Megapacs can be had any week on Ebay for $50 or less, most filled with converter pacs. -MT
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--- Begin Message ---What matters is the watts drawn and the WH per mile.Correct. That's .174 - .288 for AC, and about .3-.5 for DC.For equally well designed systems, the difference between DC and AC is almost insignificant. It does no good to compare literally state-of-the-art AC motor designs that cost tens of thousands of dollars to bottom-of-the-barrel designed-for-cheapness overblown forklift motors. That the forklift motors do so well is amazing in itself.That's not what I'm doing. A COMPLETE AC kit (not just motor & controller) is about $10k, not "tenS plural". And this is compared to the Advanced DC setup, which is NOT "bottom-of-the-barrel designed-for-cheapness overblown forlift motors".BTW, I'm not promoting either AC or DC over the other. It all depends on your budget, vehicle, driving needs, priorities, etc. I am seeing the market forces splitting up about evenly.Shari Prange Electro Automotive POB 1113 Felton CA 95018-1113 Telephone 831-429-1989 http://www.electroauto.com [EMAIL PROTECTED] Electric Car Conversion Kits * Components * Books * Videos * Since 1979
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--- Begin Message ---Electro Automotive wrote: > BTW, I'm not promoting either AC or DC over the other. It all > depends on your budget, vehicle, driving needs, priorities, etc. I > am seeing the market forces splitting up about evenly. I want a high performance AC motor/inverter at DC prices. And lithium batteries at lead prices! ;)
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--- Begin Message ---My Prizm gets about the same: 260-300wh/mile, depending on traffic. This is with a 156v pack of Optima buddy pairs, a 9" ADC motor and a Zilla Z1K controller, and I got about the same when the car had a 120v pack of SAFT NiCads and a DCP-600 controller.Very interesting data point. Nice to have a pair of apples to compare to (I assume your Prizm is a re-badged 1994 Toyota Corolla 4 door).I don't think AC offers really anything much in the way of efficiency per se, it's main advantage from my point of view is lack of maintenance (brushes?) and lack of shifting (single speed). The regen is nice in that it helps a bit in stop-and-go and *really* cuts down on the brake pad replacement.I'll be building this 94 S10 of mine out with 260 flooded NiCD cells; should be interesting to see how it performs.Chris
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--- Begin Message ---At 12:40 PM 16/02/06 -0800, Cor van de Water wrote:Actually this is an example of how a series-connection of switches that each cannot handle the full voltage can be catastrophic if one element fails. <snip> OK, this has little to do directly with EVs, but whenever I read about contactor welding/arcing, I always think of this amazing video clip at Google of a 500 kV switch being thrown open at a Nevada power switching station: http://video.google.com/videoplay?docid=4468957986746104671 DarinHi AllThis comes up every so often on this list, unfortunately I clipped off the posting date when I saved the following comment in December 2003:(Quote)********This is a 3 phase 500KV motor operated disconnect that is NOT intended to be opened under load. There is a switcher that is designed to open under load in the circuit that is supposed to open load and then the disconnect opens. In this case, one phase of the switcher failed to open, resulting in one phase of the disconnect opening under load. The resulting arc was truely spectacular. The reason that this event was caught on camera is because this particular switcher has had a failure to open in the past so every time the switcher was opened, a camera has been set up. This time they got the failure on tape.I originally got it as an internal E-Mail here at work (I work in Telecomm for Southern California Edison). I talked to one of the substation operators at the substation where it came from (near Hesperia, Calif) to get the information on how they happened to have a camera on it.I personally have been on the substation where this took place and have seen the switchgear involved. The video does appear to be the location it is reported to be. Therefore, I am treating it as factual.----------------------- Jim Walls - K6CCC [EMAIL PROTECTED] Mobile Radio Operations Southern California Edison Co. (end quote)***** RegardsJames
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--- Begin Message ---I bought one of these things, thanks to ebay. Does it work? I dunno. It does get warm. It does use about .5 of an amp of energy. I was skeptical of this thing having a pulse so i scoped it and it does, hum at 1khz. SOOOOO, does it work? I dont know. I have been recharging the batt pack and range has been extended. 10 yr old standby batts, getting excersied. That may be the answer. When my hawkers show up, I will cut one open and let you know if the sulfation is less than the ones that arent getting excersised! short story long, I dont think i would buy another. --------------------------------- Yahoo! Autos. Looking for a sweet ride? Get pricing, reviews, & more on new and used cars.
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--- Begin Message ---Arent these "aerobattery" just 2 smaller 12v hawkers in an additional case with appropriate connection hardware? --------------------------------- Relax. Yahoo! Mail virus scanning helps detect nasty viruses!
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--- Begin Message ---Date: Thu, 16 Feb 2006 06:21:46 -0000 From: "jmygann" <[EMAIL PROTECTED]> To: ev@listproc.sjsu.edu Subject: Re: looking for VW bug kit >Anyone out there who has a e-volks kit or conversion besides me ??? What vintage bug, new or old? If old, Check out http:/www.dm3electrics.com The Voltbuggy has a clutch, the Ghia has no clutch - direct drive to the transaxle. I have both adapter sets built to my specs. Jimmy
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--- Begin Message ---Christopher Zach writes: > > Very interesting data point. Nice to have a pair of apples to compare to > (I assume your Prizm is a re-badged 1994 Toyota Corolla 4 door). It's a 1993, but otherwise you're correct. Same body style. Ralph
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--- Begin Message ---Thanks for the links Great story and pics. Actually I meant to ask if anyone out there has a e-volks geo kit or conversion. --- In [EMAIL PROTECTED], Jimmy Argon <[EMAIL PROTECTED]> wrote: > > Date: Thu, 16 Feb 2006 06:21:46 -0000 > From: "jmygann" <[EMAIL PROTECTED]> > To: [EMAIL PROTECTED] > Subject: Re: looking for VW bug kit > > > >Anyone out there who has a e-volks kit or conversion besides me ??? > > What vintage bug, new or old? If old, Check out > http:/www.dm3electrics.com The Voltbuggy has a clutch, the Ghia has no > clutch - direct drive to the transaxle. I have both adapter sets built to > my specs. > Jimmy >
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--- Begin Message ---To all listers and lurkers in Sydney and surrounding areas: The Sydney branch of AEVA (Australian Electric Vehicle Association) is holding an open day. A wide range of electric vehicles, including various NSW registered vehicles will be on display at: 344 Annangrove Road, Rouse Hill SUNDAY 26th February 2006 10am - 3pm Cheers, Claudio
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--- Begin Message ---Hi Victor, Thanks for correcting my terminology - as you figured from my story I indeed meant energy per time, so power. I was actually making the point that the amount of _energy_ was practical as I assumed an average pack size of 80 Ah. Only the amount of power (current) is not at 100C rate, unless a dump pack can sustain it or a direct feed from a power plant is available. Imagine: 10,000 Amp service connection at home. I insist that you are confused about 'C'. The capacity C is referenced in many places, actually you already agreed in another place with my statement and then for the charging definition you suddenly disagree. Please re-read your own statements to see the discrepancy. I Googled "c capacity charge rate" and found may references, for example the one at: http://www.greenbatteries.com/batteryterms.html "C - Used to signify a charge or discharge rate equal to the capacity of a battery divided by 1 hour." So, by definition a charge rate of 1C will try to charge a battery in 1 hour if we neglect losses. Whether the battery can take the charge is another story, but the term 1C means that you put 0.1 Amp into a 100mAh battery or that you put 240 Amp into a 240Ah battery. It does not matter if the battery is huge or small, you charge it with its capacity (in Ah) divided by 1 hour, so the nr of Amps equal to its capacity. 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 Victor Tikhonov Sent: Tuesday, February 14, 2006 6:49 PM To: ev@listproc.sjsu.edu Subject: Re: C? Cor van de Water wrote: > Victor, > > I am afraid you are confusing things. Don't be afraid, I'm not. > The *capacity* C is MEASURED at the C/20 discharge rate, > in other words: if you discharge a battery with a current > 1/20 of its rated capacity then it's able to hold that > current for 20 hours long. > Example: 100Ah battery can deliver 5A for 20 Hours. Close, but not exactly. The battery won't be able to "hold" the current at 1/20 of its rated capacity (unless the load is regulated), the current will decline as terminal voltage drop. What they say is at that rate (if you manage to sustain it) the battery will deliver 100Ah overall. > Now the charging/discharging *current* is specified with reference > to the previous defined capacity C over a 1-hour period of time. Really? News to me. Where did you get this idea? Any references? > You see this on slow chargers (continuous/non-shut-off Nicad) > that they will put 1/10 C in the batteries and charge time is > typical 14-16 hours. The rate has nothing to do with amount of hours needed. It's all matter of capacity. 1C rate may also require 24 hrs to charge if a battery is huge. > > If you have a 100Ah battery (capacity measured at C/20) and you are > charging it at "C" then you are not putting 5A in it for 20+ hours, > but instead you are trying to charge it in 1 hour using 100A. Yes, I know 1C rate for 100Ah battery is 100 amps. Kind of obvious. > So, the 100C is extremely impressive, because this means that you > are charging a battery in 36 seconds (plus some time for the losses) > This means that a 2.3Ah call is being charged with 230A! Yes, exactly, 2.3Ah battery in 36 seconds with 230A current. So? (aside that very few batteries can handle that rate without rising temp and other damage), mathematically you're correct. > As I have written before, it is an impractical amount of energy > if you want to recharge an 80Ah pack at 100C at home, as you need a > whopping 8,000A into the pack, but if you have a dedicated dump-pack > or local generator (central charging station), it may be possible. > For floodeds it would give a whole new meaning to the term 'gas'-station. Be careful with terminology - you did not mean impractical amount of energy. You meant impractical rate of charge (current) to put in all that amount of energy (Wh) in short time. > Regards, > > Cor van de Water Regards, Victor
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--- Begin Message ---On 2/15/06, Victor Tikhonov <[EMAIL PROTECTED]> wrote: > > Now the charging/discharging *current* is specified with reference > > to the previous defined capacity C over a 1-hour period of time. > > Really? News to me. Where did you get this idea? Any references? It's true. For example, take a 200AH TS battery. The capacity, C, is specified as 200Amps for *one Hour*. (It may be measured at the 20 hour rate, I'm not sure) The maximum recommended charge current is specified as 0.3C, therefore it is 60A. Just as Cor explained. Regards Evan
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--- Begin Message ---At 03:05 PM 2/16/2006, you wrote:Andre' Blanchard wrote: > Not long ago someone here claimed to have build a 3 PH inverter from 6 > solid state relays and a bit of logic (basic stamp or something). The > battery was a 36 volts and the low voltage AC was then run thru 3 > transformers to get up to 208 VAC and used to run a fairly large air > compressor. I think he just did it to see if it would work but it does > prove that AC does not have to be as high tech as it is sometimes made out > to be. Is this design scalable up to Zilla levels? What are the upper limits of limitation of this setup?While it could be scaled up, why it is more of a prove to yourself it can be done type of thing.__________Andre' B. Clear Lake, Wi.
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--- Begin Message --- I took my pick up with the 11" net gain motor and 2k zilla to a SCCA ( sports car club of america) event last week end which has a auto cross once a month in my town . There where about 50 cars there ( all gas and all fast) . They set up a coruse with cones on this big paved driving range that the collage uses with the police to teach driving . The course is set up with lots of truns along with a few straight a ways . A great bunch of people , but I could tell that they where thinking , " an electric truck , is this guy nuts " . The girl who was checking me in , " electric , neat , is like a golf cart ?" . I didn't say anything about how fast it went , just that I wanted to see what it would do and there where some people there with their plane cars , also seeing what their daily dirve would do. This is a 2 day event with the first day as a practice . Auto cross is much more a driver skill , and car handling thing than a power thing and a corvette can get beat by a mini copper easy. We where to each get 4 runs at the course , after each run we would get back in line for the next run. The 50 cars where in two groups and my group would run after lunch on the first day. The event was about 2 miles for my house , I had used 2 ah to get there . Would I even be able to do 4 runs on a charge? Any one that wanted an instructer to drive with them or drive while they sat in the passanger seat could , and I took this oppstion . I had two reasons , one I knew that after the ride the instructer would be telling his friends about it and 2 so I could learn a little about driving . There are some momunits in life , where you get to supprize sombody with somthing so different , and seeing them see that reality was not what they though. " electicrec , whow , do I shift it like a car ?" " no just leave it in 4th " " 4th , will it take off in 4th ?" " yep" . Well as I had not done any tire spinning and up to this point as we pulled up to the starting line nobody knew what what was on the other end of that go peddle. I got to see the driving instructer deal with a major change in his reality. Lots of whow's as he soon found he had more power than the wheels could put to the ground. He got very busy driving , not alot of instructing now just whow, and ooo , . less that a minunite later we where done , and all of a sudden people are looking at my electric pick up in a different light , lots of thumbs up and now comes the questions. When I get my trun again the anowser has a lot to say about the electric truck , talking about it being in 4 th gear , and the low end troque. The e meter was the only meter I had time to look at , and I only got to see that becuse I looked at it before the run and after , the run took 2.5 ah , which is about what the BBB 1/4 mile took so I'm thinking I'm good for the 4 runs. I had a blast driving the next 3 runs , last run , on the last stright a way , I felt the voltage sage ( no I never saw any meter while driving , this must be a trick that the pro's know how to do) and knew this was the last run. There was still plenty for regular driving but after 10 ah is used , the truck is not so peppe . The next event is March 11 and 12 , more info at www.cfrsolo2.com , There is also a car show on March 11 that I go to so I may not go on the 11 , ( so many events to go to ) but on the 12th I'll be there for sure , any other EV'er that can make it let me know . I got a shot of some tire smoke and net gain put in on their site it a 1 minunit move , it takes some time to load. http://www.go-ev.com/images/Steve_Clunn.mov.Steve Clunn
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--- Begin Message ---I did a 65 mile drive to west palm , with the 40 golfers in my work truck , at 50 mph , What I do is watch the mirror , the traffic comes in waves and when I would see a new wave coming fast I'd speed up a little , after they passed it's an empty road behind and I could slow down a little . Not bad really . Funny there are sighs saying mim 40 , I wish , but all in all 50 was ok. More that once I've seen a cop in the rear view mirror and sped up.I drive freeways in California at 45mph.I strongly advocate personal choice and I absolutely support Lawrence's right to do this. While I am very glad to hear he stays in the right lane and has not had problems to date, going 45 mph on the freeway in California is very dangerous behavior, in my opinion.Steve clunn .
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