Nissan has reiterated that its Leaf battery will maintain about 80 percent of its original capacity after five years of use. This comes after a number of drivers reported that their cars indicated battery deterioration after one year, Green Car Reports says. When Nissan first revealed details of the battery, it said it expects the pack will have between 70 and 80 percent capacity left after ten years.
The drivers that reported the issue were all in the rather warm climate of Arizona and had driven the cars fewer than 17,000 miles. Nissan said that the deterioration indicators occurred in fewer than five percent of U.S. Leafs and called the incidents "isolated" in a statement. Nissan added that the deterioration is "non-linear," meaning that, while the battery will lose 20 percent of its capacity after five years, it'll lose just another 10 percent after an additional five years.
Questions about the Nissan Leaf battery packs go back at least two years, when ex-Tesla executive Darryl Siry went on record as saying that the battery pack's thermal management system may prevent it from keeping up that 80-percent threshold over five years. Nissan at the time denied the claim.
And last September, Nissan said the Leaf battery would need some maintenance after five years of steady use, but not replacement. The company estimated that Leaf batteries would still have about 80 percent of its original capacity after 60,000 miles of use, and that if the battery capacity fell below that level, Leaf owners would be able to swap out individual modules and would not need to replace entire battery packs.
Through May, Nissan sold 2,613 Leafs in the U.S. so far in 2012, which was up 21 percent from year-earlier totals but was less than half of the number General Motors sold of its Chevrolet Volt extended-range plug-in through the first five months of the year.