For my particular car, Walmart seems to sell batteries with 1 year, 2 year, and 3 year warranties. ~$70 for the 1 year, ~$110 for the 2 year, and ~$150 for the 3 year. Are these batteries actually different? If the battery with the 3 year warranty actually lasts 3x longer than the battery with a 1 year warranty, I guess it’d be the better deal, but I’m suspicious if they’re actually much different.
It looks like batteries at most other stores are even more expensive with the same warranties.
I don’t think walmart’s warranties are pro-rated. They advertise “3 year free replacement.” A couple years ago, I brought in a ~2 year old battery, and they just gave me a free replacement. All 3 batteries I was looking at have different CCA ratings, but I’m guessing ratings can be fudged too.