I believe those cells are LiFePO they are are also at risk from being stored, fully charged, at temps above 95°F. or charged at temps above 95°F. I too have ruined LiFePO cells this way.
The paper I read was talking about below freezing of water temps as problematic, but some cells can take below 0°F temps before encountering difficulty. I bet all the car companies have worked out the conditions to be avoided and manage for good cell life. (Nissan Leaf certainly had to learn about too high temps and upgrade their management.) The DIYer has to be more careful and learn more to avoid costly problems. You can't broad stroke tar all cells and cell chemistries. There has been a lot of learning and improvement in the past decade. On Tue, Oct 23, 2018 at 7:42 PM Hoegberg via EV <[email protected]> wrote: > EV <[email protected]> för Robert Bruninga via EV < > [email protected]> > den 23 oktober 2018 04:52 > Electric Vehicle Discussion List > Robert Bruninga > [EVDL] Lithium EV battery in colder weather > > > > I know that Lithium batteries perform worse at lower temps. But what > does > that mean? > > Charging, or using? which is worse. > > > The "rule of thumb": > -Avoid any normal/slow charging below zero degrees in cell temp, > > (I dont know what that is in the degrees of freedom-scale, lets call it > "below freezing") > > That rule also apply to deeply frozen laptops, cellphones and so on... > > (a sloow trickle charge might be without harm if it is not like > deep-space-winter-cold standard chemistry cell, just a bit below freezing > or so. But I do not know, probably "it depends"..) > > Li plating seems real! I think I destroyed a Thundersky, at "only" 0.3C > charging test at -28'C > > * > > Discharging cold cells seems "ok" , if you do Low C-rates. > (May be to run the battery heater for several hours?) > > The Thundersky 90Ah cells did perform *extremely* poor in my low temp > Discharge test. > Like -BAM- down to my cut off at 1.8 volt, with a very weak load.. > > > > /John > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20181023/8636ae72/attachment.html > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Michael E. Ross (919) 585-6737 Land (919) 901-2805 Cell and Text (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Tablet, Google Phone and Text -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20181023/b5c3d52b/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
