[ausev] Lithium battery suppliers to the public for use in?conversion]

[Willie McKemie]

On Mon, Oct 13, 2008 at 11:47:56AM -0500, Marc Kohler wrote:
> On their pricing page they mention 1000 cycles,
> But on their specs page 
> http://www.everspring.net/txt/product-battery-LFP40AHA.htm chart 4
> it crosses 80% of original capacity somewhere between 250-500 cycles.
> I wonder what they consider end of life conditions.
> Marc Kohler

I have no personal battery experience, but here is information I have 
gleaned from readings:
1) The LFP batteries will live longest when not completely charged or 
discharged.  Optimal life is obtained using something like 20% to 90% 
SOC.
2) The larger cells (maybe starting at 160ah) are rated for 
significantly longer life than the smaller ones.  The larger ones are 
RATED for 3,000 to 4,000 cycles.  I haven't heard of anyone that has 
reached 1,000 cycles.  Yet.
3) ->I<- would consider end-of-life to be less than 80% of original 
capacity.
4) There is a LOT of negative stuff floating around about ThunderSky.  
However, there is little to none about TS LFPs.
5) There MAY be a patent infringement issue with TS LFPs.
6) Since it seems detrimental to draw 2C or 3C, the larger cells are 
most attractive.  I chose 260s which I hope to keep below 500 amps.
7) TS seems to be about the only "right now" lithium EV solution.  The 
situation may well change if ReVolt or others get a BMS working for K2 
(or other).  BTW, I plan to use Rod Dilkes' BMS:
http://www.ev-power.com.au/-Thundersky-Battery-Balancing-System-.html

-- 
Willie, ONWARD!  Through the fog!
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