From my experience, which goes back a long time, you don't have to fuss with a battery if it sits in a vehicle over the winter. Just make sure it's fully charged when you shut down. (disconnecting a cable is probably a good idea but I've never done it.) Batteries last about 7 years for me. In fact, my ATV battery is 12 years old and will be sitting outside in the vehicle in temps that'll probably go to -40 at times over the winter. This winter will probably see it die off but we'll see come spring.
