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)
