Battery lease

With a price of $5499 for a new battery and a $100 monthly payment for 5 years, the interest rate is 3.4852%. http://www.torquenews.com/2250/replacement-battery-cost-bodes-well-used-leaf-market

This assumes the cost of installation is not included in the lease.

Personally, I'd rather buy the battery outright for $6500, and keep the old pack. Sure, it's only got 70% original capacity, but there are dozens of other uses for that kind of a battery.

Some ideas:
1) Time of Use offset: Charge at night, discharge during the day
2) Household battery backup. Be the only house on the block with your lights on
3) UPS. Smaller version of #2
4) RC cars. Come on, you know a model RC Leaf using an actual Leaf battery module sounds awesome.