The IBT site shows testing to 500 cycles. This is nothing like what is possible.
Life Expectancy Minimum ¥ >300 cycles (80% rated capacity) Typical 500 cycles (see graph below) Please watch the video of the lecture at Waterloo: https://www.youtube.com/watch?v=pxP0Cu00sZs On Wed, Apr 1, 2015 at 3:10 PM, Bill Dube via EV <[email protected]> wrote: > Here you go: > http://www.ibt-power.com/Battery_packs/Li_Polymer/ > Lithium_polymer_tech.html > and here is a good chart: > http://www.mdpi.com/energies/energies-07-05675/article_ > deploy/html/images/energies-07-05675-g005-1024.png > > It is very common knowledge that warmer cells perform better than cooler > cells for most battery chemistries. Chemical diffusion is more rapid at > higher temperatures and allow the battery to deliver more power. What the > battery can withstand without damage, and what particular elevated > temperature is optimal is a matter of testing on the particular cell. > > In the Formula One kinetic energy recovery system (KERS) they operate > their LiFePO4 cells continuously at greater than 70 Celsius. They get well > over 20,000 w/kg at that temperature. (Your car battery gets about 300 > w/kg to give you a frame of reference.) > > I have had a little bit of experience in squeezing maximum HP out of > batteries over the years. :-) > > Bill D. > > At 12:18 PM 4/1/2015, paul dove wrote: > >> You gave no source. >> >> So one is better than none. >> >> I've never heard or seen any paper that claims 104F will affect >> performance. >> >> >> From: Bill Dube via EV <[email protected]> >> To: Electric Vehicle Discussion List <[email protected]> >> Sent: Wednesday, April 1, 2015 1:13 PM >> Subject: [EVDL] Temperature rating (Was: ENERDEL Battery Experiences) >> >> The 104 F (40 C) limit applies somewhat equally >> to all Li-ion chemistries. The temperature is >> limited because the electrolyte boils just >> slightly above that temperature. Same type of >> electrolyte in all Li-ion chemistries thus the same limit. >> >> The cell containment vessel can make a >> big difference in this temperature limit, >> however. Cylindrical cells can often hold >> significant pressure while prismatic and pouch >> cells can withstand less or perhaps no pressure. >> Life a pressure cooker, the higher the pressure >> of the electrolyte, the higher temperature you >> can withstand. The A123 26650M1 cells (LiFePO4) >> would withstand up to 100 Celsius (yes that is >> correct) without damage. They weren't "rated" >> that high, but they could withstand that >> temperature. They were rated for 60 Celsius (140 F). >> >> Keep in mind that the cells will age >> much more rapidly at that elevated temperature. >> They perform better, however, and you don't hold >> them that hot for very long. You must choose the >> compromise between total life-span and >> performance for the specific application, which >> is typical for most things in life. >> >> I'm not sure where you are getting your >> information. Better check more than one source. >> >> Bill D. >> >> At 10:42 AM 4/1/2015, you wrote: >> >Jeff, I am not sure why performance at ambient >> >temperatures should make anyone feel confident >> >about a cell. LFP for instance, starts to have >> >serious difficulties at 104°F if it is fully >> >charged. That is certainly ambient here in >> >North Carolina; and that is free air, not boxed >> >up with significant amperage scooting about. I >> >must tell you, I don't have an axe to grind >> >here. I simply want to point out a better way >> >to go. That is to get better information for >> >all. And better testing with in the >> >industry. ENERDEL just popped up on my radar >> >is all. They have an website that is light on >> >good information and I waded in. I am happy to >> >see that behind the curtain they may have more >> >on the ball. I have been scanning the course >> >work you provided to me, and it is very >> >nice. When ENERDEL discusses cycle life (around >> >page 279) I can see they clearly understand the >> >reactivity of the positive electrode at very >> >high SOC and how temperature makes that much >> >worse for the electrolyte. They clearly have >> >good information to work with and probably are >> >engaged with Dalhousie University or the spin >> >off Novonix to get good testing done. I am duly >> >impressed. I still have not figured out what >> >chemistry they have chosen. From what I have >> >seen so far, they speak assiduously, only in >> >general terms regarding their own cells. If >> >they are using some inferior chemistry and >> >electrolyte package it is clearly not because >> >they don't know better, so I bet they are >> >OK. Provisional blessing on them until I am >> >better educated. Thanks for taking the time to >> >address this with me. Mike On Wed, Apr 1, 2015 >> >at 10:19 AM, Jeff Major via EV >> ><<mailto:[email protected]>[email protected]> wrote: > I doubt that >> >EnerDel and its customers have overlooked >> >anything as basic > as performance and life at >> >ambient temperatures. It appears to me that > >> >Hoegberg is comparing to some float stand-by >> >application and then > misinterpreting the >> >presented data. But whatever. They have >> >millions of > cells in the field and no >> >complaints of which I am aware. > > >> >-------------- next part -------------- > An >> >HTML attachment was scrubbed... > URL: < > >> ><http://lists.evdl.org/private.cgi/ev-evdl.org/ >> attachments/20150401/e6911ad9/attachment.htm>http://lists. >> evdl.org/private.cgi/ev-evdl.org/attachments/20150401/ >> e6911ad9/attachment.htm >> > > > > >> >_______________________________________________ > >> > UNSUBSCRIBE: >> ><http://www.evdl.org/help/index.html#usub>http: // >> www.evdl.org/help/index.html#usub > >> >http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >> >For EV drag racing discussion, please use NEDRA >> >( > <http://groups.yahoo.com/group/NEDRA>http://groups. >> yahoo.com/group/NEDRA) > > -- >> >To invent, you need a good imagination and a >> >pile of junk. Thomas A. Edison >> ><<http://www.brainyquote.com/quotes/quotes/t/th omasaed125362.html> >> http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> >> >A public-opinion poll is no substitute for >> >thought. *Warren Buffet* Michael E. Ross (919) >> >585-6737 Land (919) 576-0824 >> ><<https://www.google.com/voice/b/0?pli=1#phones > >> https://www.google.com/voice/b/0?pli=1#phones> >> >Google Phone (919) 631-1451 Cell >> ><mailto:[email protected]>[email protected] >> ><<mailto:[email protected]>michael.e.ros [email protected]> >> -------------- next >> >part -------------- An HTML attachment was >> >scrubbed... URL: >> ><<http://lists.evdl.org/private.cgi/ev-evdl.org /attachments/20150401/ >> dc67ff6e/attachment.htm>http://lists.evdl.org/private.cgi/ >> ev-evdl.org/attachments/20150401/dc67ff6e/attachment.htm> >> >_______________________________________________ >> >UNSUBSCRIBE: >> ><http://www.evdl.org/help/index.html#usub>http: // >> www.evdl.org/help/index.html#usub >> >http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> >For EV drag racing discussion, please use NEDRA >> >(<http://groups.yahoo.com/group/NEDRA>http://groups. >> yahoo.com/group/NEDRA) >> >> _______________________________________________ >> UNSUBSCRIBE: <http://www.evdl.org/help/index.html#usub>http://www. >> evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA (< >> http://groups.yahoo.com/group/NEDRA>http://groups.yahoo.com/group/NEDRA) >> >> -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/ > attachments/20150401/dc887436/attachment.htm> > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ > group/NEDRA) > > -- To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 585-6737 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150401/cbb2c1b5/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
