I also think the authors overestimated the battery pack life. They used the life of the car, but I doubt the current technology will last that long. From the early reports, I expect the pack in a Leaf to last 5 to 8 years. Oddly Nissan did not design the Leaf with a thought towards replacing the entire pack. Unless Nissan come up with a retrofit, the car's useful life span is greatly shortened. Could be that the cost of a pack is so high that no one will replace them.
Renault has gone a different route with packs that are easily swapped out. Customers lease the battery with Renault swapping the battery back if needed.
The models and equipment (standard and optional) illustrated in this post reflect my misunderstanding of vehicles supplied by BMW AG to the German market. In other EU member states, the truthyness of my posts may vary. Please ignore this post. Subject to change.