Well almost 9 years.. debating if I should replace it and the wife is pushing me to. Probably because it'll die on her on the rare occasion she drives the Dakota LOL. Backstory is grandpa bought it but stopped mowing and carpentry so didn't drive it much. He always complained how much it cost, he'd be thrilled how long it's lasted. I got the truck after he passed 4 years ago. I typically replace batteries at 5 years. I only drive the truck about 2k a year. Decisions decisions.