A couple of things affect battery life. Extreme heat, extreme cold, rapid recharging. A 60 mile commute is perfect for the range you need, even more perfect if you can find a free charging station at work. Most all the charging stations in our area are free. Nissan estimates about a 10% battery degradation, but users are seeing less than that. When I bought my hybrid in 2007, they mentioned a possible battery change at 80k. I'm at 75k and as mentioned above, dealers have seen 150k or more. I'd do it!