In my limited experience with older lithiums, I am guessing that the "swelling" that you have observed may be a side effect of batteries not being stored properly banded or strapped together. The contents of most lithium batteries is in a paste form, and has a tendency to settle to the lowest place in the case, causing the somewhat flexible sides to bulge out. I would recommend pressing the battery between 2 boards in a vise for a short time to regain the proper shape, and then banding them all together, before attempting to bring the charge up to the full state of charge. As for the current state of charge, this looks to be the proper value for longer term storage, and I would expect that these batteries will serve the user almost as well, if not just as well as a newer pack. I have managed to resurrect batteries that have been stored at lower levels, a well as some at the 3.1 level, but the 3.1's had significant loss in capacity (most likely from internal deterioration (rotting)). Just my 2 watts worth here, -Tom
On Thu, Sep 12, 2013 at 8:02 AM, tomw <[email protected]> wrote: > I wouldn't mess with them unless they are almost free for two reasons: the > swelling, and the "relatively quick" drop to 3V after charge to 3.6V. If > charged as David outlined (CC then CV at 3.6V to 0.05%C) it should require > several hours or longer for them to drop to just under 3.40V. > > I had reason to un-band some of my cells after about 3 years use and none > showed any swelling. When pushed together without banding there was no > noticeable gap between cells at the edges. > > > > -- > View this message in context: > http://electric-vehicle-discussion-list.413529.n4.nabble.com/LiFePO4-Questions-tp4665134p4665144.html > Sent from the Electric Vehicle Discussion List mailing list archive at > Nabble.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) > > -- 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/20130912/cba1b0cd/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)
