Based on previous promises from Nissan (very few batteries will need to be replaced before 100 K miles. and that cells will be individually replaceable, I will wait to purchase a 3 y/o used 2.0, if they prove to be worth while. http://www.plugincars.com/replacing-ev- ... 22261.html
Simon Sproule, a Nissan vice president, says that it’s unlikely that whole LEAF packs will need to be replaced when the magic 75 to 80 percent threshold is reached. Instead, he said, EV medics can find bad cells and replace them, at a cost of hundreds of dollars, not thousands. I hadn’t heard that before, but LEAF salesman Paul Scott tells me that it’s possible to “replace certain underperforming cells rather than the whole pack.”
Ferry says that not all packs are designed for the replacement of individual cells or modules, though the LEAF pack definitely is. Omo Velev of AeroVironment, who consults with the California Center, said that EV packs are designed to maintain even degradation across all cells, but in practice some go bad faster than others. If enough of them do that, the utility of the while pack is compromised.