tag:blogger.com,1999:blog-6676835811534572362.post81006018203681912..comments2024-02-06T10:02:20.731-06:00Comments on EVTV.ME: Follow the Yellow Brick RoadJack Rickardhttp://www.blogger.com/profile/15936311474215791697noreply@blogger.comBlogger61125tag:blogger.com,1999:blog-6676835811534572362.post-48925954189460116272011-10-18T09:14:49.447-05:002011-10-18T09:14:49.447-05:00YOUR NOT GOING TO LET IT GO.
One hundred monkeys,...YOUR NOT GOING TO LET IT GO.<br /><br />One hundred monkeys, trolling through Google seeking scraps of information to support their already docked up world view CAN FIND THEM. If you have NO basis for understanding, NO training, and NO experience, just randomly read shit until you HEAR or SEE what you WANT to see to support your view. This is EXACTLY the driver to NOT spend my valuable time on YOUR BLOG or YOUR FORUMS. It just devolves to nonsense.<br /><br />IF you really want a definitive discussion of electrolytes, THE MAN in Kang Xu. http://www.tinhoahoc.com/Battery/cr030203g.pdf is the document. And it does cover the electrolytes we use. THE LIMITATIONS ultimately described in summary are low temperature (-20C) and high temperature (+50C). The dielectric electrochemical window, of no particular importance and alluded to, involves oxidative components on the anode and cathode and have nothing really to do with a "break down voltage".<br /><br />For those TRULY interested in the role of electrolytes and their history, this is a REASONABLY readable and reasonably exhaustive treatment of the topic by someone who both knows and understands what he's talking about.<br /><br />In any event, I assure you it's more than you want to know at that. But it does explain our low temperature charging restrictions.<br /><br />jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-21983031027487818482011-10-18T07:59:46.790-05:002011-10-18T07:59:46.790-05:00Andy, there is no way to spin this into Jack being...Andy, there is no way to spin this into Jack being correct. Since Jack does not want to discuss the topic further I created a post on my blog for more discussion if anyone wishes.<br />http://ephase.blogspot.com/2011/10/battery-electrolyte-breakdown-voltage.htmlJPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-19941097453382182402011-10-17T14:33:44.038-05:002011-10-17T14:33:44.038-05:00JP, Jays video depends on current at that voltage....JP, Jays video depends on current at that voltage. Current is the killer when charged. Who needs to go much over 3.55V anyway?<br /><br />In all of Jay Whitacre's charges, he demonstrates a fully timed current feed then knocks it off. That means no voltage limiting or the charge current would be tapered down with cell voltage rise. I=V/R<br /><br />Don't forget, for sapping transients these cells will with no issues. After all, they are basically capacitors. If you want these regenerative braking transients to place a charge into the cell it will have to be maintained for over for a good few (to very many) seconds. Meaningless and pointless.<br /><br />You can charge them over 3.4V then let go. Give it a few hours, that extra voltage has gone!!! It's just like a surface charge. Waste of time.<br /><br />This hectic discussion is barely in the same ball park as overcharging all night because of a faulty B*S.Andyjhttps://www.blogger.com/profile/11910687437796998340noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-68087787585543015752011-10-17T13:11:15.489-05:002011-10-17T13:11:15.489-05:00Fine, I'll simply end with this, go to the 50 ...Fine, I'll simply end with this, go to the 50 minute mark in Jay's video and listen as he talks about electrolyte solvent breakdown above 4.3 volts, equivalent to water electrolysis at 1.3 volts, and then continue to pretend voltage doesn't cause electrolyte to break down independent of heat. Feel free to assume Jay has no idea what he's talking about.JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-2817727093214031602011-10-17T09:30:50.148-05:002011-10-17T09:30:50.148-05:00JP:
You have out of context excerpted comments wi...JP:<br /><br />You have out of context excerpted comments with no apparentl understanding of them at all. Venting and gases come from heat, and voltage is very indirect. It is very different from a "breakdown voltage". Your ability to comprehend this in context is apparently pretty limited. A very good reason for me to avoid getting drawn into it.<br /><br />You are striving to have an Endless Debate that belongs, as I'venoted several times, on EndlessFear or EVDL NOT HERE (in ALL CAPS). You're on my blog and I will certainly type into it in any style that pleases me and I take grave offense that you would offer to correct me on style issues. I've been writing in printed publications, for a living, and on blogs and forums for 32 years now and with no small success.<br /><br />I don't know what you'r on about, but I AM going to ask you one final time to take it somewhere else.<br /><br />Jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-11557301943776600942011-10-17T08:24:02.458-05:002011-10-17T08:24:02.458-05:00I never said anything about charging to 4.2V damag...I never said anything about charging to 4.2V damaging cells, I was talking about the claim that higher voltages had no effect on the cells. The fact that you held a cell at 8V or so for a few minutes proves nothing, you have no idea what long term damage you may have done. You could have shortened it's cycle life from 2000 cycles to 1800 cycles and never know the difference. In practical use it won't matter and you'll never see such voltages anyway, but that's quite different than saying an electrolyte held at a higher voltage doesn't degrade. I'm not saying it does but I've seen enough references to it from enough people, including battery researchers, that I'd like a bit more proof than Jack typing in capital letters that it doesn't exist. If you can't provide such proof that's fine, but the concept of electrolyte stability in relation to voltage seems quite common in battery literature. Indeed, in the lithium battery video by Jay Whitacre he says the following about the voltage of LiFePO4 vs LiCo:<br />"By virtue of it's lower potential the electrolyte is more stable and there is much less chance of it evolving gases that can lead to venting and combustion"<br />You can find that at the 11:50 mark. So we have a direct reference to voltage affecting the stability of electrolyte from someone who actually makes batteries.JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-33453531780558813892011-10-17T05:04:53.375-05:002011-10-17T05:04:53.375-05:00JP,
"Typing oneself smart". Not you my g...JP,<br />"Typing oneself smart". Not you my good man, the text quoted.<br /><br />The copy/pasted piece is a complete admission to no facts, just conjecture. <br /><br />Don't be taken in by simple words or you will be forever the slave to the minds of others. When they have your mind, they have your money.<br /><br />Delphi once an engineering giant for the automotive sector is now defunct. Hmmmmm.Andyjhttps://www.blogger.com/profile/11910687437796998340noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-29834292627513066532011-10-17T00:14:30.838-05:002011-10-17T00:14:30.838-05:00You know JP. I did NOT bother to read the link. ...You know JP. I did NOT bother to read the link. Now I have. And now I remember why I didn't bother. <br /><br /><br />HAD YOU read the link, the reference to an voltage breakdown in electrolytes was in 2001, and it is an entire paper on an overview of cell balancing techniques and BMS design parameters.<br /><br />Three years ago, I myself was trying to design a BMS. I'm not now. We've moved on. And we've learned a lot.<br /><br />The link you provided is NOT about breakdown voltage in electrolytes, it's a passing reference to something the guy clearly knows nothing about, but doesn't matter because we don't use those electrolytes now anyway.<br /><br />Theres a big long roundabout story I can go into about how some electrolytes in some devices are also the current barrier. Our electrolytes are ion charge carriers and we use perforated propylene ad a current barrier. But it just IS NOT WORTH IT. This is in relation to WHAT in this video and WHAT on this blog. It's so far off topic it doesn't matter and it cites random garbage from space that doesn't' matter. Why would I want to spend ANY time chasing your links and refuting this BS one by one to what point at all?<br /><br />IF you believe that exceeding 4 v will harm your cells then don't' DO that. I have already DEMONSTRATED ON CAMERA CHARGING A CELL AT 8V with NO DAMAGE AT ALL nearly two years ago. And I've assured you that allowing an individual cell to go to 4.0, 4.1, or 4.2v does NOTHING in and of itself. That the VOLTAGE doesn't matter out of context, and ONLY matters in the context of how much energy is in the cell.<br /><br />You disagree with that I gather. Noted. Now, if you want to offer an easy to put together test that YOU YOURSELF have performed and gotten a different result, and want me to verify it, we'll talk. If you want to randomly collect GARBAGE from EVDL and every other written source you can find because they are INDUSTRY SOURCES and because it is in WRITING I have zero interest in the topic. Appeals to authority don't work here because we've busted them too many times over too too many years in too too many fields WAY beyond EVland. <br /><br />Show me something odd you've found with voltage and cells on your test bench and I might become interested in it. Defending my statements against your disbelief based on BS you've dredged up from forums and Google has zero interest level FOR ME. As I've said, there is no shortage of people to debate that with you, there is just a shortage HERE.<br /><br />JackJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-41356276813366389812011-10-16T21:40:01.638-05:002011-10-16T21:40:01.638-05:00That was a quote from a paper done by Delphi Autom...That was a quote from a paper done by Delphi Automotive Systems, if you bothered to read the link. It was not an opinion piece from myself or anyone on the EVDL, though the link was hosted there. So I've quoted three separate industry sources discussing electrolyte breakdown voltage, and I'm the one indulging in fiction?JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-44932763498928717542011-10-16T16:35:33.303-05:002011-10-16T16:35:33.303-05:00JP said...
"Regenerative braking can cause pr...JP said...<br />"Regenerative braking can cause problems<br />for Lithium Ion batteries because the instantaneous regenerative braking current inrush can cause battery voltage to increase suddenly, possibly over the electrolyte breakdown threshold voltage."<br /><br />Two "can"'s, a "possibly" and adding in words like "instantaneous" and "battery voltage to increase suddenly".. Sorry young fella, this is a non-fiction area.Andyjhttps://www.blogger.com/profile/11910687437796998340noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-87651212747524186792011-10-16T14:50:39.245-05:002011-10-16T14:50:39.245-05:00JP:
If you want to drag forum nonsense into this ...JP:<br /><br />If you want to drag forum nonsense into this blog (EVDL) and quote it as authoritative, I not only cannot help you, but there is a REASON I'm not reading that nonsense on EVDL anymore. <br /><br />And if you want to debate it, take it to EVDL.<br /><br />We're just not going to do that here.<br /><br />You're trying to have a discussion of the breakdown voltage of antifreeze. I've answered the question.<br /><br />Jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-60202458552634968062011-10-16T14:02:11.998-05:002011-10-16T14:02:11.998-05:00My interpretation has been that voltage break down...My interpretation has been that voltage break down is independent of heat break down. I've heard reference to different cell component pairings that would have higher voltage than current lithium chemistries but would need development of an electrolyte that is stable at higher voltages than most existing products. That suggests to me that it is indeed the voltage that is the issue.JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-1554314661688453822011-10-16T12:25:45.924-05:002011-10-16T12:25:45.924-05:00JP,
In looking at the links you privided, I am qu...JP,<br /><br />In looking at the links you privided, I am questioning now if the electrolyte break down could be electrolytic instead of thermal. Not trying to type myself smart, just confused.cztreehttps://www.blogger.com/profile/04234930515670145794noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-23890740864268098042011-10-16T11:55:20.207-05:002011-10-16T11:55:20.207-05:00I'll leave further testing to you CosMiik. I&#...I'll leave further testing to you CosMiik. I've done enough field testing to be confident in the results. I mount my cells between aluminum end plates and then bolt the end plates down instead of boxing the cells. This leaves the end cells in a block considerably more exposed to Seattle weather. I'm finding no drift between the center and outsides of the pack.EVfunhttps://www.blogger.com/profile/07583226003313385558noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-6809380727466618902011-10-16T11:23:08.398-05:002011-10-16T11:23:08.398-05:00When I heard the term breakdown voltage, I also wo...When I heard the term breakdown voltage, I also wondered if they were referring to voltage breaking down the electrolyte or if they were referring to the voltage that produced enough heat to cause the electrolyte to change from a liquid to a gas. It doesn't make since to me that the voltage by it's self would cause the electrolyte breakdown but rather the heat generated from that voltage. In the presentation by Jay Whitacre, he spoke of the voltage that the electrolyte broke down but did not mention if this was from the actual voltage or the resulting heat.cztreehttps://www.blogger.com/profile/04234930515670145794noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-26078453908909814982011-10-16T09:32:34.892-05:002011-10-16T09:32:34.892-05:00More directly related:
"Regenerative braking ...More directly related:<br />"Regenerative braking can cause problems<br />for Lithium Ion batteries because the instantaneous regenerative braking current inrush can cause battery voltage to increase suddenly, possibly over the electrolyte breakdown threshold voltage."<br />http://www.evdl.org/docs/li_eq_2001.pdfJPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-42165233817423568812011-10-16T09:27:01.472-05:002011-10-16T09:27:01.472-05:00"The electrolyte has NO "breakdown volta..."The electrolyte has NO "breakdown voltage" This is a preposterous notion."<br /><br />Then what are they refering to here when they talk about the breakdown voltage?<br /><br />"Silatronix organosilicon compounds can be advantageously used as replacement for conventional electrolytes such as acetonitrile and alkyl carbonates. Organosilicon compounds have lower conductivity than these competing electrolytes, but have the important advantages of lower flammability, lower vapor pressure, and higher electrochemical breakdown voltage. These features combined make Silatronix organosilicon electrolytes a disruptive technology in the energy storage field. "<br />http://www.silatronix.com/applications/<br /><br />"A third parameter for the practical electrolytes is its<br />kinetic electrochemical stability window. This was determined<br />by linear sweep voltammetry on a cell containing<br />polymer electrolytes sandwiched between stainless steel<br />working- and a lithium counter-electrode, with a lithium<br />reference-electrode. The potential of current onset may be<br />regarded as the breakdown voltage of the electrolyte."<br />http://www.cswang.umd.edu/publications/papers/33.pdf<br /><br />I didn't just make up the term "breakdown voltage".JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-76916342559233908812011-10-16T08:22:31.231-05:002011-10-16T08:22:31.231-05:00All electrolytes have a breakdown voltage.. Thats ...All electrolytes have a breakdown voltage.. Thats when it goes "BBBZZTT" inside. No doubt this is far outside standard charging ranges. In fact right into the BMS range of EV mounted Lithium balloons. haha (Just kidding).<br /><br />The apparent speed of light through various materials have always fascinated me. A radio signal through a cable is maybe around 96%. Through co-axial cable it appears to be around 60% but between the driven element of an aerial and its reflector it appears to be 105%. A tuned reflector is also around 105%.<br />Any nuclear physicists want to type me smart?<br /><br />Andrew, m1awsAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-51478339680987522242011-10-16T04:02:57.810-05:002011-10-16T04:02:57.810-05:00Thanks for the good theory EVfun. Now just have to...Thanks for the good theory EVfun. Now just have to confirm that with testing, find out the extremes, and we'll have a fact:)CosMiikhttps://www.blogger.com/profile/02534766294602223916noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-6030222926090178092011-10-15T23:13:50.781-05:002011-10-15T23:13:50.781-05:00No. The electrolyte has NO "breakdown voltag...No. The electrolyte has NO "breakdown voltage" This is a preposterous notion. Electrolyte deterioration is solely a function of heat - and perhaps something we do not have diagrammed well at the intercalation point as this is where breakdown components seem to migrate. The electrolyte has no cognizance of "voltage" and it has no effect on electrolyte whatsoever.Jack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-77669997556941059572011-10-15T20:04:21.283-05:002011-10-15T20:04:21.283-05:00Jack,
You mention that higher voltages when char...Jack,<br /> You mention that higher voltages when charging do no damage if the cell is not full:<br /><br />"I can make the cell voltage 10v for 10 seconds and it does nothing to the cell."<br /><br />but if you are above 4.5V aren't you above the breakdown voltage of the electrolyte, and therefore potentially damaging the cell?JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-65288146690559817692011-10-15T18:14:51.293-05:002011-10-15T18:14:51.293-05:00Jack,
Your explanations above about balancing and...Jack,<br /><br />Your explanations above about balancing and charging PROCEDURES has to be the clearest I've seen put into one place. Hopefully more people get it now.<br /><br />@EVfun: I hadn't thought of the voltage difference due to higher IR as the compensating factor with cells of different temperatures. Thanks for pointing that out.<br /><br />David D. NelsonGizmohttps://www.blogger.com/profile/03556169075856492902noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-51154164026366005262011-10-15T15:31:22.280-05:002011-10-15T15:31:22.280-05:00"So putting the same amount of energy in two ..."So putting the same amount of energy in two cells with very different temperatures causes the warmer cell to receive more charge than the cold cell, in which some of the energy goes in heating the cell. To make sure, I do not claim to know this happens, but if someone has hands on information on the reality of what happens, or even good theories, I would welcome this information most warmly."<br /><br />That bit right there contains the key issue you missed. The cold and warm cells that are in series do not receive the same amount of energy. Because they are in series they receive the same amount of current, but that current will cause the colder cell to have a higher charging voltage. That extra measure of voltage, times the current, is the extra watts of heat that warm the cell and make the problem go away. Since the cells receive the same amount of current (same number of electrons) they move the same number of Lithium ions back to the other side and so the same amount of charge is returned (unless you go so far off in the extremes that side reactions start happening.)EVfunhttps://www.blogger.com/profile/07583226003313385558noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-88507334181896715582011-10-15T11:22:12.531-05:002011-10-15T11:22:12.531-05:00I don't know. Sounds plausible.
JackI don't know. Sounds plausible.<br /><br />JackJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-29442774437026116092011-10-15T08:20:24.976-05:002011-10-15T08:20:24.976-05:00Jack.
Could capacitors or parallel cells at the e...Jack.<br /><br />Could capacitors or parallel cells at the ends of the pack act as a reservoir to help prevent sag during acceleration until the rest of the pack catches up?<br /><br />Randycztreehttps://www.blogger.com/profile/04234930515670145794noreply@blogger.com