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Christopher Fischer has been a busy fella. He offered a little help with the web site here at EVTV and I'm guessing wonders what he got himself into.
The index is coming along famously. If you go to our archive of past shows page there is a link to this index. This is the most often requested feature on the service - how to find where they talked about x in the past 100 episodes.
But we're also getting startling response to our planned fall convention - EVCCON. Chris has produced us a signup page and database that he spend nearly 24 hours continously on to get it up quickly.
http://www.projectooc.com/evtv/evccon_signup.php
We've added a PayPal function to allow payments by PayPal or by any of the popular credit cards.
I've also been canvasing speakers. The latest to agree is Dr. Dennis Doerffel of Southampton University and most particularly the principle in REAPSystems - a BMS manufacturer. I was particularly avid to get this man as a speaker. I'm a bit of a fan of his 2007 Doctoral thesis Testing and Characterisation of Large High-Energy Lithium-Ion Batteries for Electric and Hybrid Electric Vehicles
He was publishing papers on these cells going back to 2003. He knows quite a bit about lithium ion cells and most particularly the Prismatic cells from China that we use.
We're getting to a pretty great group of speakers already.
Jack Rickard
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Didn't you suspect a REAP system as the culprit in burning the converted Nissan on that ferry?
ReplyDeleteThat is correct.
ReplyDeleteJack Rickard
I'd love to put Jay Whitacre and Dennis Doerffel in the same room and let them fight to the death....much prefer Jay, BMS free one day at a time!
ReplyDeleteDennis and the british EV club were perhaps first in the world posting some meanigfull info and experience on the quality (now much improved) and real life parameters of first gen TS baterries in the early/mid 2000s, organizing group buys etc. Those were the pioneers (among few others globally) opening the market for diyers, don't ever forget that.
ReplyDeleteDon't forget about providing some serious charging infrastructure for all that EVs.
ReplyDeleteAdditionally, remember that some of them will have BMSes ;) so... beware.
Jack did reckon on having a bonfire.
ReplyDeleteI know I will have the Miata rolling by Sept cause the 104 CALIB cells are arriving next week. I would love to bring my car to the EVCCON 2011. But its so far it would literally take like a whole month out of my life just to drive there. So I'm left with either towing it or just flying into St Louis. Hmm decisions decisions.
ReplyDelete--Jim
In the paper. Why does he keep charging the batteries to the nth degree?
ReplyDeleteMaybe to prove that it goes too the nth degree. :) I'm only on page 35
ReplyDeleteOh BTW Great job to see the bench test so smooth with the extra bracing and air fans on the Dual 11's. Can I make a recommendation? I would just use paper filters. The commutators really don't like oil. But I really like the whole idea of running those old turbo intake fans. I was also thinking to quiet them down just run the intakes to the stock air filter. The stock air filter is really designed to quiet things down.
ReplyDeleteThanks for the great show!
Hi guys nice bench !
ReplyDeleteabout the generator have a look at this site
http://www.yachtboutique.com/BentleyMarine/AEPS.htm
stil using the siemens
regards
Fjord
Solarj, The air filters should not have that much oil on them in the first place, oil does not evaporate, therefore no contamination will occur, coms. don't mind a small amount of oil anyway, they have products like "Com Lube" to do that very job.
ReplyDeleteJack,
ReplyDeleteI agree with you on the battery charging procedure. It seems that no matter how much I try to point out that the lower the ending current the lower the ending voltage should be that no one listens or even thinks it is relevant. Since my Zivan charger ends in the less than 200mA range I have it set to stop at 3.485vpc. I haven't done a full capacity test but I'm quite sure that this is still 99% or more charged. Since CALB lists 3.4v as a float voltage I don't think I'd want to charge to a higher voltage than this. I hate to think of what I was doing to my cells when I charged them to 4.00vpc with such a low ending current.
David D. Nelson
It's an issue. What they list as a "float voltage" is the OCV - open circuit voltage of a fully charged cell. Some have taken that as permission to "float charge" these cells and it is a disaster.
ReplyDeleteThis is part of the Chinese vs American dialogue and it is hilarious. But understand that any question posed with sufficient repetition WILL elicit an answer. If enough people ask them for a float voltage, not realizing that there is no such concept with these batteries, the Chinese will simply come up with one. 3.400 volts. If you insist on self discharge data, in the face of no self discharge mechanism in the cell at all, they will simply add one <2% per month. And that will kind of account for a calendar "aging" in capacity that occurs as well.
It is easier to come up with a ready answer than to explain that your question makes no sense to them. How many furlongs per fortnight? Answer: 7. If they translate the request and insist it must be answered to sell the cells, the engineers will respond, and of course that gets translated back. Seven furlong per fortnight. Or perhaps =or < 1 per fortnight.
Jack Rickard
I'm unaware of ANY oil in the K&R filter. It's just a fancy paper filter on the Turbocharger inlet.
ReplyDeleteJack RIckard
It's supposed to be oiled cotten. With the oil to help trap dust. Hence the wash out filter part. And I think you ment K&N
ReplyDeleteFor those of you who want to know more about the meaning of "Unobtainium"
ReplyDeletehttp://en.wikipedia.org/wiki/Unobtainium
It's gotta be added to the oxford Dictionary!
I wonder what voltage the CALB or WB cells could be held at so that they are just under full and no current flows? It may be temperature dependent but I'm not too sure about that. I don't see how holding the cell at 3.300V, for example, can continue to charge it since my cells sit at 3.325V when at about 75%SOC. Whether the 3.4V "float voltage" CALB gives is true or a translation issue is hard to tell. There is too much of the "all batteries are the same" mentality getting in the way of what really is. Knowing this "max" OCV would be helpful in figuring out the proper charging process for chargers like mine which dribble the current into the batteries at the end of charge.
ReplyDeleteThe best thing about K&N air filters is the fact they are serviceable.
ReplyDeletehttp://www.knfilters.com/cleaning.htm
I guess charging these cells to risk boiling the electrolyte might explain a few things. The end of the paper is not much more than a BMS advert.
What a great blog this is! Good, considered, worthwhile opinions instead of people being trolled.
GIZMO:
ReplyDeleteThe reason we do video is so you don't have to read. Read my lips. NO FLOAT CHARGE.
The "true" open circuit voltage of a FULLY charged LiFePo4 cell is 3.4000 volts. That has NOTHING to do really with your charge voltage. Do NOT keep streaming current into these cells at ANY apparent voltage. They are NOT Pb cells. And they do not need to be "held".
Jack Rickard
Jack,
ReplyDeleteI'm putting together a test bench similar to yours but using a standard 3 phase industrial ac motor with dc injection braking as the load. In theory at least , varying the dc current in the stator will vary the load applied to the rotor. I'm not sure how your siemens motor / generator would react to that but may be worth a look. Obviously that won't help with your quest for over unity!
Damien
I stand corrected. I was unaware these K&N filters were oiled.
ReplyDeleteI had a 1954 Dodge with an oil bath air filter. The air filter was actually a piece of foam rubber and it sat in motor oil held in the bottom of the "pot".
I use the term "unobtanium" to refer to desireable EV components that DO exist on the web, apparently offered for sale, and described in exquisite detail and appear to be readily available products. Except for the fact that they do not exist, are not produced, and indeed this very PRETTY website is the front for a company who rarely actually exists beyond in the mind of the web operator. No production. No actual sales. But fantastically detailed photos.
Similarly, if no pricing is listed, it is usually unavailable or so expensive it might as well be.
Jack
Damien:
ReplyDeleteSo where can I learn more about this DC injection braking for 3 phase motors.
Jack
Jack,
ReplyDeleteHere are a few descriptions and a video showing the effect:
http://en.wikipedia.org/wiki/DC_injection_braking
http://www.claytonengineering.com/training/myweb6/Module16/Output/BrakingMotor.html
http://www.youtube.com/watch?v=V0P7mp7jbG0
I tried the idea in small scale last weekend with a small 3hp motor and a 12v battery. Worked well. For the full size system i'll be using a 15kw motor and an old 72v scr based forklift charger. By varying the scr firing angle i can , in theory anyway! , control the stator current and hence braking action.
The only downside is heating due to the motor stator being fed with dc and turning into one big electromagnet.
Damien
People should click on Damien's name and check out his website. He has a lot of videos chronicling his EV build. I was a bit surprised how much content was there.
ReplyDelete- Nick F
Jack,
ReplyDeleteI do get it that there is no float voltage. I know that the cells don't have to be "held" at any voltage. It is quite simple actually. No self discharge = no float voltage.
What I want to know is if a cell is connected to a constant voltage source, what is the highest voltage that source can be such that the cell will not get over charged if left indefinitely. Why do I care? I have no control over the ending current of my charger. It tapers down to less than 200mA and holds the voltage for ~45 minutes with this low current turning on and off as needed to hold the cutoff voltage. If I knew the maximum voltage that a cell could be held at indefinitely with no overcharging I could set the cutoff voltage on my charger according to that.
I hope that makes sense.
David D. Nelson
Jack:
ReplyDeleteNice to see you getting the transmission safely up to speed.
I'm coming around to trying to keep the 6L80e and giving it a bash. The highest percentage way to do it, since you have the HELM manuals and all the sensor voltages, is to keep the ECM, harness and all the sensors that you can all intact (in a box) under the hood. The ones you can't, like a knock sensor or O2 sensor, you could likely spoof knowing the correct output or resistance value ranges from the manual. That's easier than dropping the ECM and trying to spoof the entire CAN data stream it provides the transmission. You'll also likely preserve the function of other and unpredictable systems doing that. Anyway, don't forget John Spears in Indiana if you go that way. He's a master in that game and I spoke to him about a year ago on your behalf: speartech.com.
It also seems to me there is one HUGE advantage an automatic (fluid drive) EV has over a solid driveline that I've never heard any one else mention:
You won't kill the motor holding the car on an incline with the throttle.
Its a natural part of driving to use the gas pedal to hold the car on an incline in traffic. That's how you drive a car with an automatic transmission, and its such an ingrained habit I can't imagine everyone hasn't done it in their EV. I know you did until George Hamstra saw it and freaked a little on you...
No doubt that procedure will quickly melt loose and lift the comm bars and worse. Its a serious risk in any EV with a solid driveline that operates from zero RPM, particularly in the hands of an EV newbie. With an automatic, even the tightest converter is going to slip to at least 1000 rpm, so the vehicle can safely be held at a street light, or crept up a hill in traffic while the motor labors at a low, but not immediately destructive speed.
That's a big deal, at least to me. It makes daughter (or in my case, wife) mode a great deal safer for the equipment, more reliable, and just more car-like to drive.
I will bet that operationally, you wind up sitting in the Escalade at stoplights, holding back your idling Frankenwarps with your foot on the brake pedal, which they will also be boosting to make easier for you, heating up your transmission. Man, that's decadent. The greens are going to love and hate this truck all at the same time.
See you in September,
TomA
Just to clarify why I bring John Spears up again:
ReplyDeleteHe was the first guy to tell me, when I was asking around about the 6L80e, "hey, its not rocket science; if you're deliberate and determined, it can probably be made to work. There's a lot to figure out, but its not impossible. The crank position sensor alone is more than half of the problem..."
To be fair, he also never tried to run a computer controlled transmission without the engine at all, and he couldn't imagine how it would work without preserving the ECM, even if crippled by bad and/or missing sensor inputs.
For anybody else out there hacking a late-model GM powertrain, wiring harness or processors, this guy "Speartech" is the real deal for helping figure it out. I have no affiliation with him, nor am I a customer, he's just the most qualified guy I found in a month of looking.
TomA
ECEDRA Directors with Team Haiyin EV Racing will be attending. We will be bringing our 1981 Camaro Drag Car "Warp Factor II".
ReplyDeleteLook forward to meeting you all.