Peri Hartman via EV wrote:
If you're building from scratch, wouldn't it be just as easy to insulate the battery and provide a small electrical heat source? If well insulated, how much power would it take? 100W or so, or am I completely off.
It would of course depend on the physical size of the pack is, and how well insulated it is. But in general, the batteries already generated waste heat from charging and driving. If the bus is used every day, that may be enough all by itself.
An inch of styrafoam insulation on all sides of my battery box was all it took to keep the lead-acid golf cart batteries in my ComutaVan warm in Minnesota winters, just from the waste heat.
Lithiums are more efficient; but most BMS for them dump lots of waste heat from balancing. So it may work for them as well.
I think the fundamental problem is that big companies simply don't know that battery temperature management is a problem, and they won't listen or learn from the historical experience of others that have tried to do without it -- and failed.
-- In software development, there are two kinds of error: Conceptual errors, implementation errors, and off-by-one errors. (anonymous) -- 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)
