I have been reading some research papers on this and freezing or just below freezing is not a problem. Way below freezing requires you to back off on the current.
If you knew some details about the electrolyte used, more could be said. For my own purposes, in temperate central NC, I am not worried. I plan to charge at 0.3C and not below 20°F If any one is interested I can post some notes on what I am learning. On Mon, Jan 13, 2014 at 1:35 PM, Rick Beebe <[email protected]> wrote: > I'm using CALBs in the truck I'm building. Since it's been below > freezing for the past month I'm very concerned with this. I had enclosed > aluminum boxes built 2" bigger than the size of the cells. There's an > inch of insulation all around the cells. I put a sheet of aluminum on > top of the bottom insulation and Farnum battery heater(s) on top of that. > > The heaters are connected to the incoming AC. I don't think I'll need > them while driving (easily revisited if I need to). Each box has a > temperature probe. The idea will be to turn the heaters on if, when I'm > plugged in, any of the boxes is below say 40F. I haven't decide on the > max it will heat them to yet. > > It will also suppress the charger until the temp is above some temp. > Maybe 45 or 50. > > At $15 each, the Farnams are not inexpensive when you need 10 as I did. > But it's a small price to help protect a $5500 pack. > > --Rick > > On 01/10/2014 10:25 PM, zeke Yewdall wrote: > > I wouldn't expect the batteries to get to 120F when outdoors below > > freezing. That's just what the mats get to indoors when heating only > > themselves. I'd be shooting more for 60f battery temp. And these > > are calb lithiums. > > > > Z > _______________________________________________ > 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/20140113/eb806006/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)
