The second occurrence of the same malfunction was just a few days after the warranty period ended.

FORBES: Readers Say

Studies have shown that most major breakdowns occur after the warranty period expires, and that in most cases, the repairs cost "about the same" anyway.

ENGADGET: Earth to consumers: extended warranties are a bad deal

The intent of this warranty is to provide consumers with confidence that despite this normal battery capacity loss, they will be assured of a minimum level of capacity throughout the warranty period.

ENGADGET: Nissan upgrades US Leaf warranties, will 'restore' batteries that lose too much charge

For LEAF vehicles whose batteries have fallen below nine bars during this period, Nissan will repair or replace the battery under warranty with a new or remanufactured battery to restore capacity at or above a minimum of nine bars.

ENGADGET: Nissan upgrades US Leaf warranties, will 'restore' batteries that lose too much charge