Someone is probably confusing Li-ion with NiMH as in Prius. They benefit from a cycling that creates small "grains" and more surface for charging to take place. It definitely works.
----- A bad thing for Li-ion is putting them on the shelf fully charged. 100% SOC is just a bad idea in any case. This causes a destruction of electrolyte and isn't really the same thing as self discharge, though it is a permanent loss of capacity. The intercalation of ions into the graphitic electrode is fundamentally different from cells such as PbSO4 where intercalation does not occur. We have gone over this in the past. A well designed Li-ion cell is stable when not quite fully charged and has no disequilibrium to push a discharge. It takes a leakage path to reduce the charge. Well designed could be taken to mean no internal or external leakage circuits to dissipate charge. I am mainly trying to point out that a decrease in charge is completely different from a loss of charge capacity. It is best not to confuse them. Rubrics and rules of thumb for Li-ion are changing. Improvements to cell construction, electrode structure and composition, and electrolyte composition are changing the technology. Ultimately, degradation of Li-ion cells from just sitting will be reduced to mistakes in storage, and management - it will no longer be inherent to good cells. The life cycle and life cost of Li-ion cells is fundamentally better than other cells, in practice. Not to say something better won't come along, but at this time the hypothetical other, better cells are not used in better EVs for a reason. On Feb 10, 2016 8:51 AM, "dovepa via EV" <[email protected]> wrote: > Lithium Ion batteries can loose capacity when just sitting. Not all of it > is permanent and can be recovered by cycling the cells. > I let mine sit for over a year and some cells only had 30% capacity left. > I cycled them about 5 times before I got full capacity back. > I am not sure what sitting for longer time periods would be but I have > read papers that indicate capacity loss can be permanent > > > Sent from my Verizon Wireless 4G LTE smartphone-------- Original message > --------From: EVDL Administrator via EV <[email protected]> Date: > 2/9/2016 2:32 PM (GMT-06:00) To: Electric Vehicle Discussion List < > [email protected]> Subject: Re: [EVDL] EVLN: Smart fortwo EV Batteries' > second-life @Work> a > win-win > On 9 Feb 2016 at 4:21, brucedp5 via EV wrote: > > > To be usable in the event of a replacement, a battery requires regular > > cyclising during its storage period, i.e. specific charging and > > discharging for the purpose of preservation. Otherwise it would suffer > > from deep discharging, which can lead to battery defects. > > Huh? Who said that lithium ion batteries needed to be cycled (or > 'cyclised') while in storage? Aren't they OK when stored at around 40-70% > SOC? > > The way I heard this deal a few years ago, the idea was that when the > battery capacity was too low for use in an EV, the battery would be demoted > to grid leveling service. > > Unless this "reporter" is as clueless about this Diamler notion as he is > about how steam cars worked, in Diamler's world, it's the other way round. > > I don't think that's a world I'm interested in joining, thank you. > > It sounds like if I'm driving a Smart ED (love that designation) and I need > a new battery, I can't have one. Diamler will sell me a USED battery, one > that's been doing grid leveling for some time already. Are they going to > give me a price reduced by the proportion of already-used cycle life? > > Something smells kind of foul here. > > David Roden - Akron, Ohio, USA > EVDL Administrator > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > EVDL Information: http://www.evdl.org/help/ > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > Note: mail sent to "evpost" and "etpost" addresses will not > reach me. To send a private message, please obtain my > email address from the webpage http://www.evdl.org/help/ . > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > > _______________________________________________ > 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/20160210/cfdd1cfd/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... 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