I know there is not a perfect answer for this... but here it is.
I've got a 2005 2500 with 110,000 miles and the original batteries. I am going on a trip next week where the temps may easily get down to 15 to 20. (at home it will stay around 40) The batteries are now about 7 years old... no problems. Do I replace them before the trip? How long have your batteries lasted? No unusual stresses on them and they have never been discharged.
Comments and thoughts welcomed.
Thanks,
Richard