Dave, You can charge when it is cold, you just can't do it as fast. Or you have to put some heat to the pack - which apparently is not a new idea to many.
The typical routine - come from work, hook it up so it is ready in the AM, is likely to be slow enough. But, we now know that we don't know any of this exactly - it is dependent on the type of Li ion cells and the electrolyte package in them. The only way that is known well, is using the high precision coulometry testing methods, and that is pretty new and not wide spread knowledge. You can get a taste of this from the video I have linked to (although he never discusses cold charging at all). It is obvious that Tesla can make this work. If some DIY EV people wanted to pool resources and get testing done, then Novonix could help sort this out, or point in the direction of people with the new life testing equipment. Until that happens, we will be dependent on suppliers to do it, believing - blindly it seems - their specifications, or anecdotal evidence. You can read the papers that have been published, but research seems to address different problems than what concerns the DIY EV'er. You will have to intuit from tests of other cells what to do with your own - and you probably don't really know what your own cells are made from. One of the things in Dr. Dahn's video is a hint at how important the electrolyte package is. Just small amount of an additive can make a hude difference in cell life under different conditions. NiMH and NiCAD have their own issues. On Mon, Feb 23, 2015 at 10:48 PM, EVDL Administrator via EV < [email protected]> wrote: > This is a sobering thread. For all the conviction I hear that lithium is > the only way forward, winter is when it's clear that NiMH and NiCd - maybe > even lead - batteries are still far from obsolete. > > I know, that's why battery thermal management exists, but still - if you > can't charge your EV's battery when it's below freezing temperature - below > FREEZING, not below zero F - that's kind of unsettling. > > In a usability sense, maybe lithium batteries aren't so different from > Diesel fuel, which tends to turn to gel in extremely cold weather. > > David Roden - Akron, Ohio, USA > EVDL Administrator > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > EVDL Information: http://www.evdl.org/help/ > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > Note: mail sent to "evpost" and "etpost" addresses will not > reach me. To send a private message, please obtain my > email address from the webpage http://www.evdl.org/help/ . > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > > _______________________________________________ > 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) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150224/2384af62/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)
