Why is 50% SOC a good thing for storage?
It's not so much that 50% is "ideal". It's just that your goal is to avoid extremes. You don't want a cell to run dead, or get overcharged, or too hot, or too cold; because all of these things shorten their life.
It's a bit like a potted plant. It will die if you over-water it, or under-water it; but there is a large range in the middle that's just fine.
If you *know* your cells are at 50% state of charge, and *know* that they all have a low self-discharge rated, then you can just store them in the closet for years until needed.
The problem is that most people don't KNOW the condition of their cells. They bought them from the cheapest supplier, who also didn't test them (any more than a cursory voltage check). The manufacturer also didn't test them, because there's no warranty and they never give refunds.
This is like deciding that a plant is good because it's green. :-/ -- Scientists investigate that which already is. Engineers create that which has never been. -- Albert Einstein -- Lee Hart -- See my Xmas projects at www.sunrise-ev.com/projects.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)
