Recurrent has a fairly accurate battery health estimate tool. There are tools for directly connecting via ODB that can give you the battery health at least for

Recurrent has a fairly accurate battery health estimate tool. There are tools for directly connecting via ODB that can give you the battery health at least for the Nissan Leaf, but I haven't looked into them for years and couldn't tell you for sure. In general, lower miles is better and not from a super hot climate is better (purchased and driven in Washington State > Driven in Arizona).