Quote Originally Posted by Sit-N-Fly View Post
Consumer Reports has recommended the Walmart Everlast brand and that's what I use in my VMI Honda. I replace it every 3 years regardless. Decent price and free installation. Also, a mechanic told me that modern charging systems, particularly in Japanese vehicles, are just barely adequate (due to the never ending quest for better fuel mileage) and become inadequate once all the auxiliary equipment is added in a conversion van. So I bought a Battery Tender and put it on my van on the first and 15th of each month for a couple days. If I don't drive it for a week, the battery definitely suffers. Hell, my father had an Infinity coupe that he let sit for two weeks once while on vacation and it barely cranked over when he started it for the first time after getting back.
Replacing the battery every 3 years is playing it safe. But how do you know you're not replacing a good battery (several years more life in it) with a bad one? Infant mortality is a thing.

My BMW battery is 13 years old and has never failed. I wouldn't be upset if I replaced it earlier than necessary with a better battery (unlikely). But I would be upset if I replaced it with a worse battery (likely). After all, I doubt aftermarket batteries would be so good.

Personally, I will keep the battery until it's ability to hold a charge starts to decrease. A load tester will indicate this. They are inexpensive.