Postby Jeremy » Sun Oct 26, 2008 9:56 am
I don't know whether it's any help, but when I was reading the book on the development history of the Toyota Prius, I was intrigued by the way they dealt with the battery temperature problem. They were faced with the need to retain battery performance over a wide range of ambient temperatures, so opted to take the battery "cooling" air from the passenger compartment (it's the grill on the offside rear seat back).
They found that this was the most energy efficient way of doing it, as in summer, with the air con on, the cabin air was cool, whilst in winter, with the heater on, it was warm. The Prius system effectively recycles wasted warm/cool air from the passenger compartment, air that would normally be expelled via external vents.
Obviously they didn't have to contend with the fumes from wet cells, but the idea might still work for other battery types.
Insulating the outside of the battery compartment might help, too, although a good source of cooling/heating air would be needed when the car is running or being charged.
Jeremy