Thanks David! Jack complains about the idea of Li ions slowing down. The small amount of reading I did. put it differently saying the uptake of Li ions was slower at cold temps. If part of what motivates or inhibits the ions motion is a diffusion process, then temperature has a direct effect on this. I am happy with that theory. I am more happy just accepting the empirical data from testing:
at -20° (presumable that is centigrade? which would mean -4°F) (if that was translated to °F then it is -20°F = -29°C) They detected plating with the very high charge rates of regen braking. I think is it significant they said -20 rather than -1, I am guessing because -1 ia not a problem. Is -10, or -19 a problem? Anyway it was pretty hazy. Back to reading the journal articles. I am not so sure this will affect more than a few of us and worrying about barely sub freezing temps might be a stretch. Do we have any testing to say how sub freezing, but temperate style sub freezing will do? Here in NC It hardly ever goes lower that 15°F. For my own purposes I don't have regenerative braking as it is more trouble and cost that it is worth on pedal assist machines. I can with planning either put my small packs of batteries in a warm place or slow the charge rate. On Mon, Jan 6, 2014 at 7:24 PM, David Nelson <[email protected]> wrote: > Ok, sorry for the delay. Work comes first. I finally found the video > that VW did on the batteries. It starts at about 11:40 > http://youtu.be/6JPJcxI-q4M or > http://media3.ev-tv.me/news110213-1280.mov for a full HD version or > http://media3.ev-tv.me/news110213-iPhone.m4v for a smaller version. > > What they say and show is what I have gleaned from various sources I > have referenced in the past including a highly technical article on > electrolytes from a few years ago. This video and the one Michael Ross > posted appear to agree. > > FWIW, I usually charge right after a drive. The few times my batteries > were below 0°C I just took a drive down my hill and then back up > again. That usually brought them up to 2-3°C where I would start > charging. I used only my 1500W charger which charges at around 14A > into my 200Ah pack so it is a gentle charge which tapers down to zero > amps at 3.455V/cell. The batteries usually warmed up slightly even > with this small charge rate. I didn't have ambient much below 25°F, > however. > > HTH, > > On Mon, Jan 6, 2014 at 7:58 AM, Michael Ross <[email protected]> > wrote: > > David, please do elaborate - I have a cell charging in the garage and > the > > temps will be dropping throughout the day. > > > > > > On Mon, Jan 6, 2014 at 9:45 AM, David Nelson <[email protected]> wrote: > > > >> Discharging below freezing is ok. Charging below freezing increases the > >> chance/rate of lithium plating. I'll try to find the VW battery research > >> video where they prove this and post it later. > >> SNIP > >> -- > >> David D. Nelson > >> http://evalbum.com/1328 > >> http://www.levforum.com > >> > >> > > > > -- > > Put this question to yourself: should I use everyone else to attain > > happiness, or should I help others gain happiness? > > *Dalai Lama * > > > > Tell me what it is you plan to do > > With your one wild and precious life? > > Mary Oliver, "The summer day." > > > > 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) 550-2430 Land > > (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google > Phone > > (919) 631-1451 Cell > > (919) 513-0418 Desk > > > > [email protected] > > <[email protected]> > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140106/473cf934/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) > > > > > > -- > David D. Nelson > http://evalbum.com/1328 > http://www.levforum.com > _______________________________________________ > 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) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." 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) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140106/d48606f6/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)
