It really boils down to tow facts. 1st: cells are sent away from the production before they have been aged to find out defects. It's considered to be unreasonable practice since it takes a long time and storage space. 2nd: the first formation steps build most of the cell but there is that 5% of undone which is disregarded for better profits. I'd have to call it intentional deception. But adaptive BMS takes care of it (if available). When dealing with product integrated cell manufacturing these issues are counted in. No reason to even compare Leaf and bulk prismatic. Leaf cells are already formatted to end with specific BMS. Leaf failures with LMO was cost saving idea with passive design (which works in most places). Buy Calb/Winston/Sinopoly/Liyuan and you really need very good BMS to take care of those last steps of manufacturing. Should I again say something to about the No-BMS cult? -Jukka
2014-04-21 8:47 GMT+03:00 David Nelson <[email protected]>: > Al, what voltage range did you use your cells at? What was max voltage > and what was the charging current at that voltage? What was the > minimum voltage at rest? I ask because I have kept my cells between 3V > at rest and no higher than 3.5V under 0.001C charge rate for most of > their life and I'm not seeing what you are seeing. My cells are TS > cells manufactured 9-2009 and have been in service since 1-2010. > > On Sun, Apr 20, 2014 at 7:42 PM, Al <[email protected]> wrote: > > I have to agree with Cruisin. I took a chance on Lithium with CALB cells, > > and man have I got burned. My pack is just shy of 2 years old. It has > been > > very lightly used for only 10,000 miles and perhaps 200 cycles. The cells > > are supposed to be 100Ah. Even when new I bench tested a few at .3C and > only > > got 95Ah. Now the pack is below 80AH according to my BMS. At this point I > > have no idea what my range will be each time I drive as I have had > several > > cells lose 25% capacity out of nowhere. So much for the cheaper than lead > > mantra. > > > > 1000+ cycles - Not a chance > > 100,000 miles - You're kidding right? > > 10 years - In your dreams. > > > > Al > > > > > > CALB cells (and many others) are typical Chinese junk. > > ----- Original Message ----- From: "Cruisin" <[email protected]> > > To: <[email protected]> > > Sent: Sunday, April 20, 2014 7:05 PM > > Subject: Re: [EVDL] self-discharge of CALB 180Ah LiFePO4 cells > > > > > > > >> After selling CALB cells for over 5 years and using them in my own > >> conversion, I can tell you from experience the following. At least 15% > of > >> the cells will change so much in the first year the BMS will react to > your > >> disadvantage of early charging termination and early over discharging. A > >> one > >> year warranty that is promised is hocus. the second year will > experience a > >> 10% failure with no warning of a cell. This makes your car unusable. > >> Further > >> experience with other Chinese cells is no better, or worse. I now sell > and > >> use the Nissan Leaf module that is half the price and so far no failures > >> like the CALB. I would not ever recommend a CALB cell to any customer. > >> Those > >> that are pushing the cells like EVTV have inventory they want to unload > >> before their is no more demand for Chinese cells. My customers who have > >> converted to the Volt and Leaf cells, made by the same S Korean > >> manufacturer, are really happier with the results. No more stagnant at > >> rest > >> loses that you have experienced. Look at what cells are used in the > >> popular > >> plugin cars that are required to provide a 8 year warranty in > California, > >> no > >> Phosphate. CALB would be out of business if required to provide a 8 year > >> warranty. They don't even recognize their one year warranty. You wonder > >> why > >> you are having problems, wake up and smell the coffee. > > > > > > _______________________________________________ > > 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) > > > > > > -- > David D. Nelson > http://evalbum.com/1328 > http://www.levforum.com > _______________________________________________ > 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/20140421/d5d6cda2/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)
