The Electric Car Battery Cooling Wars Have Begun!

I'm just gonna say it: I'm not crazy about the Nissan Leaf. This all-electric car, with an alleged range of 100 miles on a charge, has never struck me as anything other than a massive attempt on Nissan's part to make up for the fact that the company lacks good transitional hybrid technologies—tech that can move us past the current generation of gas-electric hybrids, toward plug-ins and extended-range hybrids, such as the Chevy Volt.

I've also had some seat-time in a Leaf prototype and I was unimpressed. Now I learn something I didn't know when I was enduring sluggish acceleration and dullsville Euro-hatch styling: the Leaf uses an air-cooling system to manage the temperature of its battery.

This has set of some recent debate in the auto/greentech blogosphere. Earth2Tech reports that Tesla CEO Elon Musk is exasperated by the Leaf, considering its technology primitive. For the record, Tesla battery packs are liquid cooled. As are the battery packs for the Chevy Volt.

Don't write this off as some kind of weird engineering cul de sac. Thermal management is a big deal when it comes to EVs and their advanced, yet still neurotic, batteries. Here's a MINI-E test driver, expressing his concerns:

I have recorded battery temperatures as high as 119 degrees on my MINI-E and performance really suffers when the temperature gets above 105. In fact, the car refused to charge a few weeks ago because the batteries were too hot. Additionally in the winter, the range gets reduced by about 25% when the temperatures drop below 40 degrees. I have even had a few extreme instances on really cold days where the range was reduced by as much as 40%. Again, all this is acceptable for a prototype test car, but how will people react if this happens with the LEAF?

Not well, one assumes. But here's the crux of my problem with the Leaf: I think that Nissan, a small player overall in the global car industry, is trying to seize an incipient market here, and do it in a furious hurry. General Motors, on the other hand, has taken the Volt quite seriously as an engineering challenge, which is why it went with a liquid-cooled battery set-up, versus air-cooled. Ultimately, I think GM is probably stunned that the Volt is even being compared with the Leaf (but hey, that's life).

The larger question is whether temperature management will be the Leaf's Achilles Heel. An EV promising, and delivering, 100 miles per charge is one thing. An EV that can't manage that because its battery gets too hot, and then has to be recharged off the grid for long periods, may actually set full-electrics back, due to the hassles it will introduce.

I'm planning to keep an eye on this as both the Leaf and the Volt get closer to market this year.