The Wh losses generate more heat in then cell which breaks the electrolyte and operation of active particles. When particles loose their ability to release and capture Li-ion's Ah's are lost. Creating imbalances further since power capability is related to parallel operation of active particles.
We'll see soon 1st vehicle with 10 active years on TS cells (LFP). Daily operation and on the road. Then.. we *know* more ( scheduled 10 year inspection :P ). We got 8 years on NMC but replaced the cells to LiFePO4. Wh losses were already taxing the usability of the vehicle. -akkuJukka http://www.google.com/profiles/jarviju#about 2013/6/15 David Nelson <[email protected]> > On Fri, Jun 14, 2013 at 9:05 PM, Lee Hart <[email protected]> wrote: > > > > > > > As Don Blazer said, while the resistance of an individual LiFePO4 cell > can > > be quite low, there can also be large differences between cells. He's > seen > > 2:1 on the CALBs. I've seen 4:1 or more (on Thunderskys). > > > > > So how do you calculate the theoretical charge storage difference between > cells when the ESR isn't really the same as what a resistor does? Diffusion > differences alone will cause an effective resistance to differ and yet not > change the charge storage efficiency. If there is a theoretical value of > the SOC difference between two cells which started out at the same SOC > after they have been cycled a given number of Ah then we could check with > actual use. > > I think that one of the things that is possibly confusing things is that > there is no theoretical self discharge in a LiFePO4 cell where there is in > a lead acid cell. > > -- > David D. Nelson > http://evalbum.com/1328 > http://www.levforum.com > > Nokia Lumia 920 Windows Phone 8 > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130614/49303134/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) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130615/d820f7c8/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)
