People are always worried
People are always worried about the battery on the car. That is why I did a 2 year lease and at the time of delivery, I was planning on turning it back in at the end of the lease. After a year with the car now, however, I like it so much that I may extend the lease another year, or buy it...it all depends on what works out best financially.
After 13 months and 13,000 miles, I have experienced no perceivable battery capacity loss...my range remains within 5% of what it was when brand new.
First, consider the cost of fuel. 60,000 miles at 50 miles per gallon and $3.00 per gallon means you will spend $3,600 on gasoline to drive 60,000 miles. With the Leaf, I average about 4.0 Miles per kWh and pay $0.08 per kWh, so my fuel cost is approximately $1,200 to drive 60,000 miles. I will save $2,400 in fuel costs alone over 5 years. Don't forget to multiply your effective hourly wage by the amount of time you will spend standing in the heat, cold, wind and rain at gas stations. Plugging the Leaf in every night and unplugging it every morning while closed up in my insulated garage adds approximately 15 seconds to my day.
Now I hear a new battery can be purchased for $5,500 after a $1,000 core credit for turning in the old battery. If you had to buy a new battery after only 5 years, your battery cost is now $3,100. Any additional life to the battery over 5 years lowers the price that much more. After hearing this effective price on the battery, I'm more inclined to considering a purchase at the end of the lease.
Now, think about this: you buy a new gasoline car and drive it for 5 years. How much will service cost on that vehicle over 5 years? Don't forget to include your effective hourly pay multiplied by time spent servicing it yourself or driving to and from a service center. Since the Nissan Leaf power train has one moving part (the "squirrel cage" rotor of the electric motor) versus the hundreds of moving parts of an internal combustion engine and transmission, maintenance and repair time and expense is significantly reduced. I won't attempt to estimate a number, but the battery effectively becomes that much cheaper.
Finally, consider that once you replace the battery, the car will perform exactly like it did when it was new, as there is essentially no perceivable wear to the drive train. The engine and transmission in a gasoline car will have some mechanical wear on it degrading the performance. Assume you keep each car 20 years and 200,000 miles. When you put your 4th battery in the Leaf, it will once again perform as new. The gasoline car will have mechanical wear of enough significantly that it's performance will be measurably degraded. For example, my car before the Leaf was a 1993 BMW 325i. When new, that car would run 0-60 mph in 7 seconds. At 210,000 miles, 0-60 took 10 seconds. They only way to recover that performance would be a new engine.
Basically, do you want all your costs in one lump sum as a battery purchase, or do you want it all spread out in maintenance costs? For me, I am factoring in the instant torque, relatively quick 0-30 times, quiet and smooth shiftless drive train, comfort of cabin preconditioning, and convenience of never getting gas again. With all these things considered, if I had to do it over, I would buy the leaf again.