This time last year a hot item of concern among Nissan Leaf owners was the phrase "premature battery capacity loss." Several owners, especially in Phoenix, complained of rapid loss of battery capacity, a Leaf-owner-organized battery capacity test was performed, and eventually several Leaf owners filed a class action lawsuit. A settlement was reached in that lawsuit, with Nissan agreeing to expand battery warranties for the 2011-12 Leaf's, while not admitting the suit had any merit.
At issue is Nissan's claims concerning the useful lifetime of the Leaf battery pack, versus actual battery pack behavior in the field. Specifically, Nissan claims the Leaf will have 80% remaining capacity after 5 years, and 70% remaining capacity after 10 years. However, some Leaf owners were seeing degradation at a faster rate than this. A stink was raised via online message boards, which rose to become news coverage, even involving a Nissan Executive Vice President (Andy Palmer) answering questions from Leaf owners. See Nissan's Andy Palmer explains Leaf battery capacity loss to Chelsea Sexton for the gory details.
The worry is that in some cases battery degradation would render affected Leaf's useless, and those Leaf owners owning an expensive paperweight in their driveway. The degradation seemed to be worse for those who used their cars heavily, frequent fast charging, or frequent fast driving, or even just hot weather.
In making the settlement, Nissan maintains the class action lawsuit had no merit. In any case, the company is extending the warranty to add battery capacity loss to its existing limited warranty for up to 60 months or 60,000 miles, require Nissan to repair the battery to at least 70 percent of its full capacity, and if repair is not possible to replace the pack with a newly manufactured or reconditioned one.
About 18,588 people are covered by the class action settlement, and all will be automatically included in the extended warranty unless they choose to opt out. For example, if they're unhappy with the terms. Browsing the MyNissanLeaf forum, we see that some indeed are unsatisfied by the settlement.
Curiously the settlement terms are identical with a warranty modification Nissan had previously announced on the MyNissanLeaf forum. That announcement also included news of a software upgrade that improves the accuracy of the in-dash battery gauge. This lead some to wonder which came first, the warranty upgrade, or the class action lawsuit settlement? Maybe Nissan was going to offer an extended warranty anyway, because it was facing a Leaf owner community where some had become outright hostile and the company needed a way to sooth the hostilities.