Nissan's early Leafs have the reputation as the cars with the most degraded batteries coming back into the used car market, and some of Nissan's earliest Leafs were sold under a "battery leasing model" where the car was sold but the battery was still under lease from Nissan giving Nissan incentive to replace the battery if it dropped below certain warranty thresholds. Yet despite the "notorious degraded Leaf battery" and decades of the Leafs existence and batteries that possibly owners could call in lease terms for replacements out there, statistics show that the vast majority of Leaf batteries are still in primary usage (people are still driving those "degraded" batteries, there is a used car market for them) and Nissan claims they've yet to see enough batteries enter the secondary use market to build even a single one of their PowerWall-equivalent products.