You provided nothing that would help us answer your question. Not even the name of the reseller or manufacturer. What kind of inquiry is that? If you won't tell us, or show us, then there can be no real answer.
"4000 cycles at %90 dod" This is a mostly meaningless specification. Taking lithium cells to 90% DOD does absolutely nothing bad to them. What might mess them up regarding DOD is if they were not consistent in their capacity and construction - so that they would not age well together for the life of the pack. What you want to know with certainty, is the voltage at 100% SOC (or somewhat lower for a factor of safety). And then the temperature beyond which the cells should not go when at a high SOC. You need to know the recommended high cutoff voltage that is sufficient to protect the cells regardless of temperature. You need to be sure your charger never pushes the cells beyond the max SOC%. If you do push voltage and SOC% higher you need to know the activation temperature of the system (positive electrode and electrolyte composition) and never let the pack exceed that temperature when the cells at at a high SOC%. What will the life of the cells be? Unless a thorough study using high precision coulometry has been performed, then you will mostly have no idea the expected life of the cells. Traditional testing tells you nothing much about the expected life. The old methods take far too long to give results and no one ever runs them long enough to get an estimate that is very certain. On Mon, May 11, 2015 at 9:00 PM, ken via EV <ev@lists.evdl.org> wrote: > I saw some pouch cells that claim 4000 cycles at %90 dod. > > any one tested theses. > > How are they for $ vs. power density. > > _______________________________________________ > 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) > > -- To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 585-6737 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com <michael.e.r...@gmail.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150511/a1bbd41c/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)