I bought my 2003 DRW 3500 in August of 2003. I still have the original factory batteries and cannot believe they have lasted this long. Now that the truck and the batteries are getting older, I am figuring it would be wise to replace them whether they need it or not. I think they call that preventive maintenance? Would it be a good idea to spend the $200+ to replace them now before winter after all this time or just wait till they start going bad and maybe end up being stranded somewhere? Gee, I think I just answered my own question. Has anyone been able to keep the original batteries much longer than 7 years?