I am not sure about which cells are better or worse, but there are cells which have problems with the Li plating onto the graphite electrode if there is too much current at lower temps. This clogs the electrode so less and less can be intercalated quickly.
Lots of interesting literature in this search: http://tinyurl.com/ycb76z8t There is a nice diagram of intercalation here: http://www.jmbatterysystems.com/technology/cells/how-cells-work The solid electrolyte interface that builds up on the positive electrode protects the electrode from degrading reactions with the electrolyte, but plated Li on the SEI reduces the "aperture" through which ions can move into the graphite flakes of the electrode. I think Tesla(s) have a heater for the battery pack to compensate if ambient temps are too low. That might be dated/archaic information. But regardless, at low temps the rate of ion transport is less at lower temps, whatever battery chemistry you are talking about. On Tue, Oct 23, 2018 at 4:13 PM Lee Hart via EV <ev@lists.evdl.org> wrote: > Jay Summet via EV wrote: > > Note that using a battery (both charging and discharging) will heat the > > battery because of the waste heat loss inherent in the inefficiencies of > > the charging/discharging process. > > That's true. But the efficiency of good EV cells is high (95% or more) > that very little waste heat is generated. And, the pack is so heavy that > this heat does not change the pack temperature very much. It's likely to > be 10 deg.F or less. > > Charge efficiency is worst when the pack is nearly full. The older > lead-acid or nickel-based chemistries could generate more heat because > they were routinely overcharged for balancing. But that's a bad idea > with lithium chemistries -- overcharging is avoided because it > dramatically shortens life! > > > QuickCharging / Supercharging will heat up the battery faster/more than > > a regular L2 charger or trickle charger. > > Yes. The faster the charge, the less efficient it is and the more waste > heat will be generated. > > -- > Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple, > reliable, straightforward, readily available, easy to use, and > affordable. 2. Not what the salesman wants you to buy. > -- > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com > _______________________________________________ > 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/20181023/5330023e/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)
