I bought my 04 in Texas in 07 with 110,000 miles now almost 170,000 I try real hard not to drive this truck in our lovely N. In. winters, but do start it and let run for 45 min. to an hour every month or less, as it does sit in the cold. I do wait for a mild day so they don't have to work so hard. Batteries are original as far as I know, with no sign of failure yet. We are going to Alaska in the spring, I've been thinking I should change them, but, if it ain't broke why fix it. I think a good HD jump box sounds like an excellant alternative for insurance only.