I have by no means kept up reading papers on Li developments, but this sounds purely speculative. I have never seen any testing indicating this (exactly not this, is more like it). I can't imagine what about this hypothesis syncs up with how Li cells work. Sounds like a conflation with some other non-lithium cell.
On Oct 5, 2016 11:10 AM, "Thos True via EV" <ev@lists.evdl.org> wrote: > Peri, > > My thinking on the degradation has to do with the fact that most people do > not actually discharge the cells below 50 or 60 percent. > I learned from some of the people involved with the lithium cells that it > is best to think of them as a "sponge". That is, if you leave a sponge > soaking in a bucket, it rots very quickly (always plugged in or charged), > and if you leave it on a shelf all the time, it becomes very hard, and > takes a very long time to re-hydrate (prolonged low charge). However is you > wring it out on a regular basis, lasts for a very long time (regular full > charges and discharges). This is why it was recommended to fully discharge > ie. wring out (according to the instrumentation) once per month. > I know that it worked well for me. > > -Tom > > On Wed, Oct 5, 2016 at 7:10 AM, Peri Hartman via EV <ev@lists.evdl.org> > wrote: > > > Something doesn't make sense, here. No doubt you prolonged the battery > > capacity by not charging and discharging fully, per the engineer's > advice. > > > > But according to what others have said, if you consistently charge to 80% > > and discharge to 20%, you should see very little or no capacity > degradation > > with LiFePos. Yet the vast majority of Leaf owners do see significant > > degradation and never see thermal runaway. > > > > So, either LiFePos need even a smaller margin of operation, say 35% to > > 65%, or what the engineer told you isn't completely true. Or there's some > > other significant factor in the situation. > > > > Peri > > > > ------ Original Message ------ > > From: "Thos True via EV" <ev@lists.evdl.org> > > To: "Cor van de Water" <cwa...@proxim.com>; "Electric Vehicle Discussion > > List" <ev@lists.evdl.org> > > Sent: 05-Oct-16 7:00:20 AM > > Subject: Re: [EVDL] To fully charge or not to fully charge that > > isthequestion > > > > I'm not sure why this keeps coming back to roost. Some people on this > list > >> may recall the same conversation back in the spring of 2011, where I > >> contacted Nissan about the 80% issue. I received a phone call from one > of > >> the engineers in Tennessee. He understood my confusion and expressed > some > >> frustration at their end, explaining that they designed the on board > >> battery management system to protect the batteries. Doing so by never > >> letting the batteries charge above 80% (which shows as the full 100% on > >> the > >> instrumentation), and never discharging below 20% (which shows as 0%). > >> Explaining that if you let the battery pack get below 10%, it would > >> typically brick (not allow a charge), and above 90%, that your could > >> experience a thermal even ( Thermal runaway & fire). > >> The final recommendation from him was to discharge the pack to 10 miles > or > >> so in range (according to the instrumentation), and fully recharge about > >> once a month to "refresh" the battery. I followed his advice, and after > 39 > >> months and 56,000 miles, (the end of the lease), the pack was still > above > >> 98% capacity, which seemed to surprise the service department at the > >> dealership where we turned it in at. > >> I suspect that some of the degradation that we experienced may have been > >> due to some of the fast chargers that we used toward the end of the > lease, > >> but have no way to be sure of that. > >> > >> Tom True > >> > >> On Tue, Oct 4, 2016 at 11:39 PM, Cor van de Water via EV < > >> ev@lists.evdl.org> > >> wrote: > >> > >> Let's try that *with* the link: > >>> https://techcrunch.com/2016/09/29/tales-from-a-tesla-model- > >>> s-at-200k-mil > >>> es/ > >>> > >>> > >>> Cor van de Water > >>> Chief Scientist > >>> Proxim Wireless > >>> > >>> office +1 408 383 7626 Skype: cor_van_de_water > >>> XoIP +31 87 784 1130 private: cvandewater.info > >>> > >>> http://www.proxim.com > >>> > >>> This email message (including any attachments) contains confidential > and > >>> proprietary information of Proxim Wireless Corporation. If you > received > >>> this message in error, please delete it and notify the sender. Any > >>> unauthorized use, disclosure, distribution, or copying of any part of > >>> this message is prohibited. > >>> > >>> > >>> -----Original Message----- > >>> From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Cor van de > >>> Water via EV > >>> Sent: Tuesday, October 04, 2016 11:28 PM > >>> To: Electric Vehicle Discussion List > >>> Subject: Re: [EVDL] To fully charge or not to fully charge that > >>> isthequestion > >>> > >>> Here is the article about the 200k mi Tesla (in 1 year) Note that > >>> Tesloop is actually aiming at putting 400k mi on their cars each year, > >>> so the 8 year warranty on battery and drivetrain would give them ~3 > >>> million miles under warranty... > >>> Their website has a blog with a few of the details, including an early > >>> front motor replacement under warranty. > >>> > >>> Cor van de Water > >>> Chief Scientist > >>> Proxim Wireless > >>> > >>> office +1 408 383 7626 Skype: cor_van_de_water > >>> XoIP +31 87 784 1130 private: cvandewater.info > >>> > >>> http://www.proxim.com > >>> > >>> This email message (including any attachments) contains confidential > and > >>> proprietary information of Proxim Wireless Corporation. If you > received > >>> this message in error, please delete it and notify the sender. Any > >>> unauthorized use, disclosure, distribution, or copying of any part of > >>> this message is prohibited. > >>> > >>> > >>> -----Original Message----- > >>> From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Cor van de > >>> Water via EV > >>> Sent: Tuesday, October 04, 2016 2:06 PM > >>> To: Willie2; Electric Vehicle Discussion List > >>> Subject: Re: [EVDL] To fully charge or not to fully charge that is > >>> thequestion > >>> > >>> Willie, > >>> Not dynamically, just a one-time upgrade (dealer visit required). > >>> Many Leaf owners who lost the 4th bar and thought they qualified for > the > >>> warranty battery replacement were miffed to see the dealer really > >>> enforcing the Nissan requirement that the warranty will only be > honored > >>> after the mandatory re-calibration of the 12 battery bar gauge. Most > >>> owners found out that after re-calibration their earlier 4 bar loser > no > >>> longer showed 4 bars lost so they no longer qualified unless they > would > >>> again see 4 bars lost on the re-calibrated gauge. The first bar does > not > >>> disappear until 15% is lost and each subsequent bar should stand for > >>> 6.25% so in theory you need a battery degraded to just over 66% of > >>> nominal capacity to qualify if the gauge will indeed drop to 4 bars > >>> right at that point. But reports I have seen of Ah capacity > degradation > >>> suggest that the loss of the 4th bar happens later. > >>> I found it significant that Leafs can lose more than 40% capacity in > >>> about 50k mi while some Tesla drops only 6% in 200k mi. > >>> > >>> Of course this is only one sample with a specific usage pattern, but I > >>> highly doubt an expansion of the samples will give different results, > >>> we'll see. > >>> > >>> Cor van de Water > >>> Chief Scientist > >>> Proxim Wireless > >>> > >>> office +1 408 383 7626 Skype: cor_van_de_water > >>> XoIP +31 87 784 1130 private: cvandewater.info > >>> > >>> http://www.proxim.com > >>> > >>> This email message (including any attachments) contains confidential > and > >>> proprietary information of Proxim Wireless Corporation. If you > received > >>> this message in error, please delete it and notify the sender. Any > >>> unauthorized use, disclosure, distribution, or copying of any part of > >>> this message is prohibited. > >>> > >>> > >>> -----Original Message----- > >>> From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Willie2 via > EV > >>> Sent: Tuesday, October 04, 2016 11:18 AM > >>> To: Electric Vehicle Discussion List > >>> Subject: Re: [EVDL] To fully charge or not to fully charge that is the > >>> question > >>> > >>> On 10/04/2016 12:29 PM, Cor van de Water via EV wrote: > >>> > on the battery as the Leaf *does* degrade its battery by 40% to > approx > >>> > >>> > 60% capacity in approx 50k mi in warmer climates (that is the point > >>> > where Nissan gives a warranty battery replacement, even though they > >>> > promised 70% but re-calibated the battery to lose the 4th bar around > >>> 60% > >>> > capacity and triggering the warranty if it occurs within the > warranty > >>> > limits for time and mileage.) > >>> When I first got my Leaf, I was astonished at how crappy the > >>> instrumentation is/was. Coming from the conversion world, I expected > to > >>> > >>> see, or find out, how much energy went into the battery and how much > >>> came out. Instead, I had these twelve "bars". Unacceptable > granularity. > >>> Later, I found the "bars" were not even of equal value. > >>> After some pondering, I came to the conclusion that Nissan did things > in > >>> > >>> that way to hide information from their customers. What other > >>> explanation could there be? > >>> > >>> Even more astonishing is how Leaf owners accept the situation and > speak > >>> of almost meaningless "bars". I'm not surprised to learn that Nissan > >>> dynamically recalibrates "bars" to manage their warranty threshold. > >>> > >>> _______________________________________________ > >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >>> http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >>> Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV > drag > >>> racing at NEDRA > >>> (http://groups.yahoo.com/group/NEDRA) > >>> > >>> _______________________________________________ > >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >>> http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >>> Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV > drag > >>> racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > >>> > >>> _______________________________________________ > >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >>> http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >>> Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV > drag > >>> racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > >>> > >>> _______________________________________________ > >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >>> http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >>> Read EVAngel's EV News at http://evdl.org/evln/ > >>> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/ > >>> group/NEDRA) > >>> > >>> > >>> > >> > >> -- > >> Remember, it is not that the glass is half empty, in reality, the glass > is > >> merely twice the size that it needs to be! -TNT'82 > >> -------------- next part -------------- > >> An HTML attachment was scrubbed... > >> URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/ > >> 20161005/594baeca/attachment.htm> > >> _______________________________________________ > >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >> Read EVAngel's EV News at http://evdl.org/evln/ > >> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group > >> /NEDRA) > >> > >> > >> > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > Read EVAngel's EV News at http://evdl.org/evln/ > > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group > > /NEDRA) > > > > > > > -- > Remember, it is not that the glass is half empty, in reality, the glass is > merely twice the size that it needs to be! -TNT'82 > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/ > attachments/20161005/7e7aa9d7/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at 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/20161006/76774e05/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
