Nissan tries to gauge expectations on battery life

leaf-two-of-themeditors-blog-entry3Just got – and filled out – an online survey that indicates Nissan is fishing for information on people’s expectations surrounding the battery pack for the LEAF.

Seems Nissan is trying to determine what type of warranty to offer on the LEAF battery pack. Based on the survey questions, it appears the carmaker is leaning toward two options:

  • A 5-year/60,000 mile warranty, or a more robust 8-year/100,000 mile warranty.

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Again, based on the survey questions, some of which query prospective LEAF buyers about how much they’re willing to pay for extra battery warranty coverage, I have a feeling Nissan is going to opt for the shorter warranty and then pitch LEAF buyers an extended warranty for which you will have to pay more.

Personally, I would feel much better about Nissan and the LEAF if it offered the 8-year/100,000 warranty without charging me extra for it – which is what GM is doing with the Chevy Volt, whose battery will have an 8-year/100,000 mile warranty. This would indicate Nissan has a good amount of confidence in the LEAF battery pack. Of course, if the LEAF pack can’t live up to an 8-year/100,000 mile warranty, then it would be foolish for Nissan to offer such a warranty.

Battery life a true, rubber-hits-the-road issue
Battery life and the anticipated range of the LEAF are true rubber-hits-the-road issues. And reading and responding to the survey questions, which are much more direct, and, one might say, more honest about the current limitations of electric car battery packs, definitely had an impact on me.

leaf-side-viewHere’s one of the survey passages that had a strong effect:

“The rate of battery capacity loss for the Nissan LEAF can vary by individual. For instance, more aggressive acceleration and braking, or extreme hot temperatures over 120 degrees, could cause a more rapid loss of capacity over time. Conversely, smooth driving, or moderate climate, could result in less capacity loss.”

I’m well aware of the fact that how hard one drives an electric car has a big impact on its battery charge capacity, and therefore, its efficiency and range. But it’s nonetheless interesting to see Nissan explicitly writing about these limitations. Generally, if one reads LEAF ads and other marketing materials aimed at the general public, it would seem that the LEAF’s range is 100 miles – period.

Some EV advocates – for instance, Chelsea Sexton – have criticized carmakers for not being as clear about the fact that a LEAF, or a MINI E, etc. might sometimes go 100 or more miles, but other times might make it just 70 or fewer miles – for instance, if it’s very cold out and the driver is cranking the heater and driving the EV very hard.

Will average consumers grasp battery capacity loss?
EV advocates like Sexton fear that average people who know little about EVs won’t understand that driving conditions affect capacity and range. That’s because they don’t understand this issue — or at least don’t pay attention to it — with gasoline cars, which also see reduced fuel economy in extreme cold and heat, and, of course, when they are driven hard.

nissan-li-ion-battery1Sexton’s right to have this worry. So, it’s good to see Nissan be more explicit in this survey about the effects of weather, driving style, etc. on EV range — albeit a bit indirectly, as the carmaker actually refers to battery capacity, not range, though the former clearly is related to the latter.

Another interesting passage from the Nissan LEAF survey also focuses directly on battery pack charging capacity loss. This is a fairly complex issue, one veteran EV-ers know a lot about and discuss quite a bit with one another, on and offline. However, the non-EV expert will need to make a significant adjustment to grasp, and come to terms with, capacity loss. Here’s the passage:

“Assume the Nissan LEAF capacity is 80% after 5 years, or 70% after 8 years, on average, but could be higher or lower depending on these factors [weather, temperature, driving style, etc.].”

The life of an EV battery pack
It’s my understanding that an EV battery pack is not able to effectively power a heavy automobile after it drops to about 70 percent of its charging capacity. If LEAF owners hit this barrier in eight years or less, they’ll have to invest a lot of money in buying a new battery pack pretty early in the car’s life (cars are now easily lasting 15, even 20 years, as my 1992 Acura Integra attests!). This reduces the fueling cost advantage — typically claimed to be about two or three cents a mile as opposed to three or even four times that for a gas car — of owning an EV, even one powered 100 percent by electricity generated by a home solar system, which ours will be.

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I know some current Toyota RAV4 EV owners have gone over 100,000 miles on an original battery pack. But the RAV4 EV packs are nickel metal hydride-based, not lithium ion-based. I also know many RAV4 EV owners have had to replace their battery packs after getting seven or eight years out of those packs – at fairly substantial cost, meaning several thousand dollars.

The reduction in battery charge capacity issue isn’t going to stop me, a big EV, or, really, a big PV+EV advocate, from making the switch to an electric car. But it definitely makes me uncertain about whether we’ll see as much savings by tapping the PV+EV synergy as I might have hoped for.

And, if I’m feeling uncertain, people who are not EV advocates – meaning most people – are likely to experience even greater unease when confronted with the issue of batter capacity loss and having to potentially replace the LEAF’s battery pack after only seven or eight years of driving on it.

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