Marcus Reddish via EV wrote:
Are these the old white Thunder sky cells that failed? Seem to remember a
picture of them leaking. Is it possible folks charged those early cells
like they were lead and caused (or contributed to) the failures? I have
not heard of any bad "batch" since the white cells, which was ages ago.
Willie2 via EV wrote:
The situation Lee describes dates to 2000-2003? Something like that. I
know nothing of the situation but I believe they were LCP cells.
Starting about 2005, LFPs were the preferred cells for conversions. I
know of no quality or delivery problems with ThunderSky LFPs.
My earliest ones were from a group buy organized by Victor Tikhonov in
2003. They were white prismatic Lithium-Cobalt cells, in both 90ah and
100ah models. Some of the 100ah cells were OK (maybe 3 out of 4 worked,
but didn't meet specs). *All* of the 90ah cells were junk. Some leaked,
but the main problems were low amphour capacity and excessive internal
resistance. Resistance on the 90ah cells was so high that they
overheated even with a 25 amp load.
Maybe some of the purchasers abused their batteries and caused their
failures; but I certainly didn't.
I've continued to borrow, barter, and buy various lithiums for testing.
Prismatics and cylindrical, LiCo, LiMn, LiFe etc. They have
*consistently* failed to meet specs. Typically, their amphour capacity
and internal resistance are out of spec, with large variations between
cells, and a number of bad cells mixed in with the good. The most recent
ones were GBS 100ah LiFe cells, tested just last year. The only
exception has been A123 3.2v 2.5ah LiFe cylindrical cells; they were
consistently good.
I'm forever hopeful that the manufacturers will "get their act together"
and start delivering an honest quality product, and stand behind them
with a warranty. But so far, if I'd spent good money for a full pack of
any of these batteries (except A123), I would have been screwed.
At the moment, I'm considering getting some Nissan Leaf cells to test.
I'm guessing that Nissan is likely to have made a *significant* effort
to get a good, quality product. I just have to make sure I'm not getting
Nissan's QC rejects!
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading
Or do these great deeds, worth repeating.
-- Ben Franklin, from Poor Richard's Almanac
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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