Leaf: Plus and Minus

To avoid sending money to the oil cartels, a correspondent for the Christian Science Monitor has purchased a Leaf battery electric vehicle, and posts about it in My Nissan Leaf life, Parts 1, 2, 3 and 4.

Nissan has erected a new lithium-ion cell fabrication plant next to their vehicle assembly plant in Smyrna TN, and sometime in 2012 will start producing the 2013 Leaf in America as well as Japan. The 2011 and 2012 Leafs used battery cells from Automotive Energy Supply Corp (AESC), a joint venture between Nissan and NEC, but the Daily Yomiuri Online claims that the 2013 Leaf will use less expensive Hitachi battery cells instead. Nissan won’t comment, but why build a new cell plant if you’re outsourcing cells? Less expensive cells may enable Nissan to increase the Leaf’s 73-mile EPA rated range or to reduce the Leaf’s asking price.

Meanwhile, the saga of battery capacity loss in Phoenix AZ Leafs continues. Without a Temperature Management System (TMS) for their battery packs, Nissan may have a hard time selling any sort of Leaf in hot climates. Nissan sent a letter to owners that had complained about losing capacity:

… Battery data collected from Nissan LEAFs to date currently indicates that less than 0.3 percent of Nissan LEAFs in the U.S. (including vehicles in service dating back to December, 2010) have experienced a loss of any battery capacity bars. Overall, this universe of vehicles represents a very small fraction of the more than 13,000 Nissan LEAFs on U.S. roads. Also, data received globally from other LEAF vehicles shows that this condition typically occurs to high-mileage cars or those in unique operating situations. …

On the MyNissanLeaf forum, a Leaf owner responded:

You can make statistics support just about any position and although I appreciate the above response from Nissan, stating that only 0.3% of Leaf’s nationwide present with this problem is misleading. Looking at the 42 Leafs … of the approx. 400 vehicles sold/leased in the Phoenix area … shows this issue affects at a minimum, 10% of the cars in Phoenix. Nationwide 1 in 300 (0.3%) cars sold have presented with this issue. In Phoenix, 1 in 10 have this issue and that is only based on known wiki reports. This stat alone demonstrates that this is not a “method and frequency of charging issue, amount of electricity consumed during daily usage issue or a vehicle’s mileage or age issue”. …

Leaf owners may well be abusing their batteries through over-charging and topping off, but it also seems likely that Phoenix’s hot conditions and the lack of temperature management are making use and abuse much harder on the battery. And battery electric vehicles have a tall order satisfying our expectations. In, Battery Performance Deficit Disorder, Tom Murphy of Do the Math blog shows that the physics just doesn’t support them as a replacement for ICE vehicles.

Batteries fail—as certainly as death and taxes. Rechargeable batteries at least offer the possibility of repeating the cycle, so are in this sense more like recurrent taxes than death. But alas, the story cannot repeat indefinitely. One cheerful thought after the other, yes?  But wait, there’s more… Add to their inevitable demise an overall lackluster performance in battery storage technology, and we have ourselves the makings of a blog post on the failure of batteries to live up to their promises.

To set the stage, the specific energy of gasoline—measured in kWh per kg, for instance—is about 400 times higher than that of a lead-acid battery, and about 200 times better than the Lithium-ion battery in the Chevrolet Volt. We should not expect batteries to rival the energy density delivered by our beloved fossil fuels—ever. …

Don’t get me wrong: even though I dwell on the shortcomings of batteries in this post, I still hold a net positive view. … Despite their lackluster performance next to fossil fuel storage, batteries still beat the pants off of mechanical or gravitational storage.

And even though I might appear to be picking on the Chevy Volt by highlighting its deficiencies, I actually rather like the design point …. In fact, I was half way to buying one. By half way, I mean that if the price were cut in half, I would surely have one now.

The real point is that batteries fall pathetically short of our customary fossil fuel energy storage medium. When we wake up to a declining global availability of petroleum, we won’t just switch over to electric cars. We may not be able to collectively afford such a transition, given the huge up-front costs in both money and energy. Where will the prosperity come from? If oil shortages drive recession in the usual fashion, expensive options may be off the table.


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2 responses to “Leaf: Plus and Minus”

  1. cmaukonen says :

    I was thinking. Until an all electric vehicle becomes practical and instead of the current hybrid technology, why not take a clue from the locomotive. When an engine of some sort is there only to generate the electricity needed to power the electric motors that drive the car. If this were done, then the most efficient motor for this task could be used since it would not have to drive the wheels directly. Even some sort of small turbine could be used.

    Just a thought.


    • Donal says :

      That’s essentially how the Volt works. Electric motors drive the wheels. Batteries power the motors. An ICE engine mostly recharges the batteries, but can help power the wheels at very high speeds.


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