The new LEAF desert heat tolerance battery should be available April 2014. I like to call it the Lizard battery because it has been tested day and night at 14F to be sure it can take the heat and not lose capacity too fast. This could be a break though for EV batteries. No lost energy for cooling. In fact most liquid cooled batteries don't cool when they are parked. EV world story on the new battery http://www.evworld.com/news.cfm?rssid=31119
Nissan also seems to have the most efficient air conditioning and heating system in the 2013 LEAF. It's a heat pump so it only uses half the energy of most systems. This can be very important at times when you are pushing the range on a hot day i Phoenix AZ.
Nissan along with many others is working on batteries that will have more range and be about the same price. We'll see who has them first and just how good they are very soon. Many say 2015 will be the big break thoughts in battery range.