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Voltdriver · 07-27-2012, 02:46 PM

I don't really think there is a good case that can be made NOT to actively cool the battery. From what I have read, and it could be complete crap, Nissan couldnt get the battery size they needed, and get a 3 person bench seat, with an actively cooled battery. It added too much bulk. As a result, they had to go to a passive cooling system to remove battery bulk and reduce the cost of the car. Nissan claims that it (active cooling) isnt needed, but that is CLEARLY not the case as being seen from the hot climate Leafs.

GM went SUPER CAUTIOUS with their design. By not allowing the user access to the total energy of the battery, any degredation is hidden from the user for several years. By adding in a thermal management system, they are reducing the damage done to the battery by heat.

According to GM, they batteries are actually degrading at a slower rate than they had anticipated (10-30% at 100k miles). It is the reason they REDUCED the cell reserve on the 2013 models. When they reduced the reserve, changed the battery chemistry and added an additional .5 kWh to the size of the battery, it resulted in 3 extra miles of range.

I think GM was genius on this approach.

07-27-2012, 02:46 PM	#36 (permalink)
Voltdriver EcoModding Lurker Join Date: Jul 2012 Location: Raleigh Posts: 14 Thanks: 0 Thanked 9 Times in 1 Post	I don't really think there is a good case that can be made NOT to actively cool the battery. From what I have read, and it could be complete crap, Nissan couldnt get the battery size they needed, and get a 3 person bench seat, with an actively cooled battery. It added too much bulk. As a result, they had to go to a passive cooling system to remove battery bulk and reduce the cost of the car. Nissan claims that it (active cooling) isnt needed, but that is CLEARLY not the case as being seen from the hot climate Leafs. GM went SUPER CAUTIOUS with their design. By not allowing the user access to the total energy of the battery, any degredation is hidden from the user for several years. By adding in a thermal management system, they are reducing the damage done to the battery by heat. According to GM, they batteries are actually degrading at a slower rate than they had anticipated (10-30% at 100k miles). It is the reason they REDUCED the cell reserve on the 2013 models. When they reduced the reserve, changed the battery chemistry and added an additional .5 kWh to the size of the battery, it resulted in 3 extra miles of range. I think GM was genius on this approach.