/"In a properly designed EV, cold worries shouldn't be a big deal. The EV's battery should have thermal management, maybe even a heater for extremely cold weather operation."/ How would you manage temperature without heating in winter? As you say, it is easy to add heating to battery packs, and I would add relatively inexpensive compared to other expenses in converting a car, so I've been surprised by how many don't bother. With heating you don't notice much difference in winter/summer performance, mainly the effect of increased friction in the drive train in the cold. Battery sag is about the same. I keep the batteries heated to 65F when parked at home, and with 1/2" insulation and their heat capacity they will remain above 50F if parked outside for several hours in temp's in the low 20's. It adds at most a few hundred dollars to a $10k to $20k project, and is much easier than trying to control battery temperature in summer. Thicker insulation is used in colder climes like Canada.
The lithium batteries don't give off much heat so the insulation has some, but not a big effect on their temperature in summer. They usually remain less than 15F above ambient after a 30 minute drive. With increasing heat waves cooling will become an issue. Driving longer distances with fast charging will also make it an issue in summer. That will be much more difficult to address than just adding heating for winter, since I don't think air cooling will be sufficient. I've never not driven my ev in winter because it was too cold, even at around zero F. I have skipped driving it longer distances in summer temps over 100F. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Cold-Charging-Lithium-Experiences-tp4667675p4667719.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. _______________________________________________ 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)
