tag:blogger.com,1999:blog-6676835811534572362.post955127723964175008..comments2024-02-06T10:02:20.731-06:00Comments on EVTV.ME: Of Kits and Cars at CarlisleJack Rickardhttp://www.blogger.com/profile/15936311474215791697noreply@blogger.comBlogger27125tag:blogger.com,1999:blog-6676835811534572362.post-64632893522511974392011-07-06T06:07:13.143-05:002011-07-06T06:07:13.143-05:00Wyn:
We generally measure battery temperature dir...Wyn:<br /><br />We generally measure battery temperature directly at the cathode. I know this sounds like an answer evading the question but it isn't really. Some measurements involve heroic measures to gain more accuracy, and instead gain less.<br /><br />This is a little hard to explain. But battery temperature is very localized. because the two terminals are each at the same end of the foils, ionic migration is concentrated at those ends. Temperature rise is more centered on the cathode. And so you willl find a really quite wide variation internally from the terminal end of the cell (highest) to the off end of the cell (lowest) and from the cathode side (highest) to the anode side (lowest). And so when you say you need the "internal temperature" you haven't really specified much.<br /><br />And so the question devolves to you need the internal temperature for what? And whatever the reply is brings us right back to the same spot - at the cathode.<br /><br />Because the boiling points of the four inorganic solvents are known, we generally try to keep temperature below a value to avoid venting. That value is about 90C for the lowest boiling point as I recall. And so you will hear various mother in law figures below that, taken at the cathode, under the assumption that the external cathode temperature is lower than the internal cathode temperature. And in each telling, this mother in law figure grows until I"ve heard as low as 60C.<br /><br />In reality, the thermal characteristics of aluminum are such that I cannot imagine a differential between external cathode surface and internal cathode at the diffusion layer of more than about 1.5C, which starts to get down to the measurement accuracy of most of the inexpensive devices used for the purpose.<br /><br />Short answer is use the external cathode temperature. And add a constant correction figure if you feel better about that. But be conservative in doing so.Jack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-18699356982155569692011-07-06T01:05:36.276-05:002011-07-06T01:05:36.276-05:00I was wondering if you know the best way the measu...I was wondering if you know the best way the measure the battery's internal temperature in terms of safety. <br /><br />This is because I have to find out its heat capacity and from what I read from the research papers, the internal temperature is needed for the calculations.<br /><br />Or if you have any other suggestions, like where should I mail to to ask about this.<br /><br />Thank you <br /><br />WynUnknownhttps://www.blogger.com/profile/13170697963614695616noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-79654241426641351422011-05-31T23:57:25.770-05:002011-05-31T23:57:25.770-05:00I really liked this in your post: "Having met...I really liked this in your post: "Having met face to face, or perhaps about to, has a very subtle but strong effect on their online interactions." Reading about you pulling together the EVCCON -- which sounds like an incredible convergence of fun & learning -- shows that in addition to being able to assay analysis you really walk your talk.jisaacshttps://www.blogger.com/profile/05686186960273798777noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-42304621167265155522011-05-31T02:29:11.676-05:002011-05-31T02:29:11.676-05:00Also, I just watched the latest video and I notice...Also, I just watched the latest video and I noticed you dropped the old "outro" in favor of the new intro repeated again. I miss the old music on the outro, but do favor the new intro. Since you seemed to favor your old intro, how about a compromise and use the new intro and keep the old outro.palmer_mdhttps://www.blogger.com/profile/15935053957269354710noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-75769553937967923842011-05-30T22:45:38.375-05:002011-05-30T22:45:38.375-05:00Hi Guys,
I also love the new into. Some of the c...Hi Guys,<br /><br />I also love the new into. Some of the chirons go by a little too fast, but the concept is great. Where is "Brain"'s credit? Any remove the shot of the lead and put in some old Thundersky's or new Winston's<br /><br />Michaelpalmer_mdhttps://www.blogger.com/profile/15935053957269354710noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-56267689512854148572011-05-29T14:50:13.925-05:002011-05-29T14:50:13.925-05:00"Had it had neighboring cells to melt, and se..."Had it had neighboring cells to melt, and send THEM into a simliar condition, and so on, it could have been disastrous. All of this was at a very low charge level by the way."<br /><br />Another reason to stay away from the high end of the voltage curve. I'm staying below 3.5vpc since there is very little energy above that point with LiFePO4 cells as long as ending current is relatively low. I hate to think of how close to the melting stage I was pushing my cells when I used to charge to 4.00vpc. Jack, thanks for pushing me toward making that change and to collect my own data on the cells.<br /><br />David D. NelsonGizmohttps://www.blogger.com/profile/03556169075856492902noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-74007764229783653232011-05-29T12:16:12.049-05:002011-05-29T12:16:12.049-05:00The DVD is available at http://racinggreenenduranc...The DVD is available at http://racinggreenendurance.com/DVD/<br /><br />It's 19.99 British Pounds.<br /><br />This really should be required viewing for anyone considering building an electric car. This intrepid band has managed to have every possible EV disaster piled into one single road trip short of burning hte car to the ground. I've never seen the like.<br /><br />Jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-68988955266292704602011-05-29T12:11:46.452-05:002011-05-29T12:11:46.452-05:00Leigh:
The solvents are not really very flammable...Leigh:<br /><br />The solvents are not really very flammable. More like an alcohol fire. <br /><br />The GBS meltdown was very instructive. The heat was quite intense. That was one inch oak plank and it was charred all the way through. The reason I didn't have a worse situation was that I didn't have 40 of them crowded into a confined space and in fact there was nothing over the cells for about 15 feet. But I assure you the heat was intense.<br /><br />Had it had neighboring cells to melt, and send THEM into a simliar condition, and so on, it could have been disastrous. All of this was at a very low charge level by the way.<br /><br />The only way I know of to get these cells to burn is to overcharge them somewhat dramatically, or set a fire on top of them. <br /><br />I just finished watching RACING GREEN's documentary of their electric car drive from Anchorage to Usuaia on the Pan American Highway. Surely enough, they had a BMS fire along the way. FOrtunately, although disabled for awhile, they did not burn the cells.<br /><br />The trip is quite an oddity. Almost everything we've ever had happen happened to them along the way of this trip. Attempting to prove the viability and hardiness of the electric car, it appears to me they rather proved that you need 5 or 6 recent engineering school graduates to keep an electric car running even a short distance. The trip looked in all respects like a total disaster from Anchorage onwards. I've never seen the like. Utterly fascinating. <br /><br />The DVD is available at www.racinggreenendurance.com I think.<br /><br />Jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-57741593625128000222011-05-29T11:37:08.812-05:002011-05-29T11:37:08.812-05:00I was thinking of the comment the bystander made t...I was thinking of the comment the bystander made to his wife about the "finely tuned exhaust." Maybe the response could have been to encourage him to go check out how they tuned the exhaust and that he might really find it interesting. He might even like to try it on his regular car.Gizmohttps://www.blogger.com/profile/03556169075856492902noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-41525975246152699142011-05-29T11:30:20.020-05:002011-05-29T11:30:20.020-05:00Hi Jack,
another comment l remember watching the ...Hi Jack, <br />another comment l remember watching the video on the testing of the GBS cell where you went out to Dinner and forgot to turn off the charger and melted it. There was not much damage to the table etc and it didn't burn down your garage. Most likely because the electrolyte didn't have an ignition source.<br /><br />Regards Leigh<br />PS:- interested in what you think about these theories.Leighhttps://www.blogger.com/profile/14261609931194044447noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-29350583647460316732011-05-29T11:12:49.537-05:002011-05-29T11:12:49.537-05:00Hi Jack, must congratulate you on your new intro t...Hi Jack, must congratulate you on your new intro to the videos and enjoy the videos very much. <br /><br />I was re watching Nov 13th 2009 video on your joys of manual balancing of the batteries in the Gem and your redwood stick explanation on balancing issues. I have a question and a comment. I was wondering if the the pressure relief valve was the button thingy ( real technical term LOL) between the 2 terminals? If so I have a theory that if the cell over voltages and causes the cell to release pressure, now as l understand we have some highly inflammable organic solvents used in the electrolyte. So if we had say a very hot ceramic resistor on a BMS directly above the relief valve and the battery released the electrolyte in a high speed jet and was ignited by the hot ceramic resistor! We would have one hell of extremely hot blow torch happening that would cause a extreme high temperature fire that would ignite anything and everything in its proximity and Bang we have a high temperature fire that has consumed the car and anything nearby. <br /><br />That would explain it all.<br /><br />Regards Leigh.Leighhttps://www.blogger.com/profile/14261609931194044447noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-50013216421213989752011-05-28T07:28:14.381-05:002011-05-28T07:28:14.381-05:00Jack,
"A pound is a pound is a pound and wors...Jack,<br />"A pound is a pound is a pound and worse for electric vehicle designers, it is a permanent pound forever. If you design it in, it will be with the car on every trip henceforth, and will effect each and every single application of the throttle from thence forward. It is cruelly omnipresent. A pound is forever."<br />I couldn't agree more. The more mass an object has, the more energy it takes to move it. <br />This is why I have chosen the very difficult task of an all composite, monocoque construction with aluminum suspension. It's a lot of work, but in the end the very light weight body allows for a much smaller battery pack. <br />Your blog is a great read Jack, it keeps me inspired.<br />ThanksOrion 2010https://www.blogger.com/profile/15453827638575754185noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-14338677321057424362011-05-27T19:17:18.801-05:002011-05-27T19:17:18.801-05:00Jack,
I have designs on my car to indicate that it...Jack,<br />I have designs on my car to indicate that it is electric. This is the only way that the average person is going to understand that an electric car is a viable and dependable form of transportation. They see my car driving to work everyday and think, " maybe an electric car would satisfy my needs". Unfortunately, that "informed" person you overheard in Carlisle "educating" his wife is not in the minority.<br />Great new Intro!<br />Regards,<br />Larrytechman187https://www.blogger.com/profile/00388837079277275804noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-55416030892089254442011-05-27T00:26:58.611-05:002011-05-27T00:26:58.611-05:00The Nissan Leaf has a moving map that shades out b...The Nissan Leaf has a moving map that shades out beyond its range. The further you travel, the smaller the circle becomes.<br /><br />Obviously they took calculating charge to distance seriously.<br /><br />David, 8KW@50mph and 2KW@30mph. Air resistance eh; a range/speed killer.<br />Cedric Lynch reckons his EVFF uses 2hp (1500W) at 50mph and >200miles range but its a 2' wide, 4'3" high gherkin with modified bicycle rims. Not built solidly like yours.<br /><br />Instruments. The open source guys would have a field day if suitably motivated.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-8550224883645382922011-05-26T23:45:29.430-05:002011-05-26T23:45:29.430-05:00Redux:
57/3*180AH=3420AH/1.6AH per mile = 2,137 mi...Redux:<br />57/3*180AH=3420AH/1.6AH per mile = 2,137 mile range!<br /><br />Fit a smaller motor to make it to 60 cells for better divisibility then switch the series for better mileage!<br /><br />Wow! I think this lad is onto something. I'll inform the BMS guys right away to draw something up.<br />=============================<br /><br />Conversely, on the high voltage front. If you place Matts 650V AC motor in the GT40. You could use the 200 cells wired to each of the left/right bumpers as terminals. The uses would be endless.<br /><br />Someone run out of charge? Just go bumper to bumper, sorted!<br /><br />Park car to the bumper chargers, easy!<br /><br />A police car... Instant taiser!<br /><br />With Matts motor we should call it "AC Cobra" and fit the bumpers in the upper air intake like fangs because it will sting!Andyjhttps://www.blogger.com/profile/11910687437796998340noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-48774168590860950712011-05-26T23:13:48.872-05:002011-05-26T23:13:48.872-05:00Since an Ah meter can work with any voltage of pac...Since an Ah meter can work with any voltage of pack it is a universal meter meaning that the user only has to know what the Ah capacity of the pack is in order to effectively use it. For example, I have a CycleAnalyst in my Gizmo. All I had to tell it was the resistance of the current shunt and now it works at counting Ah. I know my pack is 200Ah so I know that my pack is "empty" at 160Ah used if I want to stay above the 80% DOD (Depth of Discharge) point. If I did the reconfigure for the 128V 100Ah pack then I would know to stop at 80Ah. It is just that the Ah would count down much slower as long as I drove it the same way.<br /><br />The ZEVA-II that Jack uses to run the regular fuel gauge works on this principal and therefore it doesn't need to know the pack voltage. The CycleAnalyst, on the other hand, runs from pack voltage so it knows the pack voltage all the time and will calculate the Wh used but it isn't on the main screen I usually use.<br /><br />I agree, however, instrumentation still has a ways to go.Gizmohttps://www.blogger.com/profile/03556169075856492902noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-88171467900067836672011-05-26T22:25:47.527-05:002011-05-26T22:25:47.527-05:00Gentlemen, thank you for your answers. Between you...Gentlemen, thank you for your answers. Between you both it's become clear.<br /><br />Anyone can think if Brian averaged 1AH and has a 180AH pack, then double them in half and go twice as far. You will need double throttle to increase the Voltage.<br /><br />They speak of speed controllers chopping to a lower average voltage when its really chopping the power. The power requirements must be the same at a given speed. So on the motor, Volts = velocity is true only to overcome the motors back emf and V/R=I.<br /><br />Maybe its acceptable to fail at consistency because universal instrumentation is lacking. Cars these days have very good consumption meters Yet something so apparently straight forward as one in an EV evades us. So far!<br /><br />thanks for the time fella's.<br />AndrewAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-84640462490064086772011-05-26T20:45:48.918-05:002011-05-26T20:45:48.918-05:00Legitimate question and a spot on answer on the AH...Legitimate question and a spot on answer on the AH/wH. The appropriate measure is of course watt hours because it accounts for a varying voltage. But most of our instruments are in Amp hours so we talk that quite a bit. They vary ridiculously. In the Mini Cooper, we have a 375 volt system, so it is not unusual to be less than an amp hour per mile though we are typically burning 325 to 350 watt hours. <br /><br />In the Speedster, it is more commonly 1.6 AH per mile, though we are really using only 225 wH of energy.<br /><br />We fail at consistency here.<br /><br />Jack RickardJack Rickardhttps://www.blogger.com/profile/15936311474215791697noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-79359922753655167672011-05-26T19:34:34.373-05:002011-05-26T19:34:34.373-05:00Ah/mi is a unit of energy consumption. If you use ...Ah/mi is a unit of energy consumption. If you use Wh/mi then you can directly compare the efficiency of different vehicles even if they use different pack voltages. For example, my Gizmo averages 140 Wh/mi from the battery pack. My battery pack is a 200Ah pack but that is only part of the story. The nominal voltage of my pack is 64V so I have a 200Ah * 64V = 12,800Wh pack. If I only want to use 80% of my capacity that means I have 10,240Wh to use. 10,240Wh /(140Wh/mi)= 73 miles. This is my useable range. Also, in this case I use about 2.2Ah/mi.<br /><br />My pack is actually made up of pairs of 100Ah cells. If I were to make two 100Ah 64V packs and parallel them I would have exactly the same amount of energy. If the electronics in my rig could handle the voltage I could have one 100Ah pack but it would be at 128V and I would still only have 12.8kWh of energy. Also, my rig would still consume 140Wh/mi but at this higher voltage I would only use about 1.1Ah/mi.<br /><br />W/mph or kW/mph is just a unit of power needed for a given speed divided by the speed. At 50mph it takes about 8kW to keep that speed. That would translate to 160W/mph. The thing is, that at a lower speed that number is meaningless. IIRC, it take about 2kW to maintain 30mph, which equates to 67W/mph. A very different result.<br /><br />HTH,<br /><br />David NelsonGizmohttps://www.blogger.com/profile/03556169075856492902noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-14534421123194520362011-05-26T13:01:27.835-05:002011-05-26T13:01:27.835-05:00I need to ask this general question. Get it out of...I need to ask this general question. Get it out of my hair.<br /><br />Is mileage calculated in AH/miles or Watt/mph(kph)?<br /><br />Brian said before testing Redux on the rolling road, his consumption was around one AH. If the three cell packs were equal and in parallel then a 450 mile range could be expected with a (1/3Voltage) lower top speed?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-75430551028499255542011-05-25T09:56:30.732-05:002011-05-25T09:56:30.732-05:00Wind noise is easily overcome. Try covering the mi...Wind noise is easily overcome. Try covering the microphones with a bit of fur.<br />====================================<br />Some say he is a man of mystery who was never born of this Earth.<br /><br />JP said...<br />"All we know is he's called The Brain."Andyjhttps://www.blogger.com/profile/11910687437796998340noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-15994304264438252262011-05-25T07:52:07.839-05:002011-05-25T07:52:07.839-05:00Excellent new opening for your show. Now it's ...Excellent new opening for your show. Now it's time to work on the ending. It was great seeing the cars on the autocross track. Good presence at the Kit Car show. Should result in some electric conversions. Or at least some thinking about it. By the way, the wind noise is not that terrible. Easy to block that out. <br /><br />Pete :)Pete McWadehttps://www.blogger.com/profile/08288980906309612950noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-79504238983096344782011-05-25T05:09:18.480-05:002011-05-25T05:09:18.480-05:00What a GREAT SHOW, as You always do Jack !!!
Than...What a GREAT SHOW, as You always do Jack !!!<br /><br />Thank you for what you do.<br />-Youri1-ev.comhttps://www.blogger.com/profile/17116596206439989986noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-89855160887894552682011-05-24T20:20:14.002-05:002011-05-24T20:20:14.002-05:00Better:
"All we know is he's called The B...Better:<br />"All we know is he's called The Brain."JPhttps://www.blogger.com/profile/01351893617814995335noreply@blogger.comtag:blogger.com,1999:blog-6676835811534572362.post-22495678222334485172011-05-24T20:19:38.955-05:002011-05-24T20:19:38.955-05:00Wow, wow, wow. All the way through. Good to see a ...Wow, wow, wow. All the way through. Good to see a couple of key guys in the EV world. Loved the pumping program start.<br /><br />Hey I said Redux with so much mass on either end wouldn't be so hot on the track. Horses for courses. It's still an ace car.<br /><br />Ironically, I'm looking to make a light (but not fast) car. The downside with light, fast accelerating EV's is using other cells like Kokams or cylindricals for higher output, smaller mass and volume but less life(?). Plus knocking off weight elsewhere gets costly in parts.<br /><br />I bet Brian would of desired some stickies for the track ;) Eco tyres have a lot more silicon for better rebound don't they? <br /><br />Good point reiterating kit cars for EV's.<br /><br />Lets hope Deux is easily fixed.Andyjhttps://www.blogger.com/profile/11910687437796998340noreply@blogger.com