The surest way to destroy a pack of LFP cells is to fully charge them and let then get hot as in over 100F.
Can you tell us the number of cells and their parallel series configuration? Then specific recs can be made. You may want to consider cutting of charging before fully charged state is reached and never let them sit in a hot place if you have charged them to a high SOC. The problem is the positive electrode becomes very reactive with the electrolyte when fully charged and temperature sets off a destructive process. I speak from experience, but also researching it. There is a long and interesting video on YouTube of professor Jeff Dahn a long time battery's researcher, discussing his. Try searching Jeff Dahn Waterloo lithium or similar. It was a lecture he gave at Waterloo University. Dahn is an electrochemistry at Dalhousie University in Novelty Scotia. On Aug 7, 2017 3:00 AM, "Matthew Quitter via EV" <ev@lists.evdl.org> wrote: > Thanks guys... but if the charger is turning off at a fixed voltage how do > I get more power into the pack? > > > > On 7 Aug 2017, at 05:02, Bill Dube via EV <ev@lists.evdl.org> wrote: > > > > I agree. Voltage on LFP cells is useless for determining the SOC. > > The voltage is very constant except at near 100% SOC and at 0% SOC. > > You really need information about the middle, and voltage doesn't give > any clue about that. > > > > You need to count the amp-hours, like with an E-meter or a Cycle-Analyst. > > > > Bill D. > > > >> On 8/6/2017 7:00 PM, Willie via EV wrote: > >> > >> > >>> On 08/06/2017 07:38 PM, Matthew Quitter via EV wrote: > >>> Hi Guys, > >>> > >>> My 1238-6501 Curtis controller gives very different SOC % for similar > >>> voltages. > >>> > >>> For example I've recorded a pack voltage of 82.2 and had the Curtis > show > >>> 22%, 31%, 43%. > >>> > >>> The pack is made up of 25 Thundersky 160Ah batteries. > >> > >> With LFP cells, you can't accurately infer SOC from voltages in the > middle of the range. The voltage/SOC curve is too flat. > >> _______________________________________________ > >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org > >> Read EVAngel's EV News at http://evdl.org/evln/ > >> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/ > group/NEDRA) > >> > >> > > > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > Read EVAngel's EV News at http://evdl.org/evln/ > > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/ > group/NEDRA) > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/ > group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20170807/e16e792e/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
