The lifespan of any lead acid battery is determined by how much of its lifespan it was kept near fully charged.
The best lead acid battery ever made, and kept at 50% state of charge will not last as long as the least expensive lead acid battery, kept at 99% State of charge.
Most have no idea how much the parasitic draws on any given battery are, nor how little the alternator can really return in that 5 block trip to the store and back.
And thus any claims of longevity of any particular battery brand are largely irrelevant, as there is no supporting data as to how the battery was treated during its lifespan. Either it starts the car, or it does not, that is all 99% of the car driving public ever knows about their battery.
I agree on buying the warranty, but if one is really trying to get the longest lifespan from a battery, they would be better off actually caring how close to 100% SOC the battery got to live its life, rather than caring who made the battery.
The person who cares about the state of charge, and takes measures to keep it near or at 100%, will likely never need the warranty.
Anytime the battery is discharged it is being abused to some degree. The longer it is left discharged and the more it is discharged the faster it loses capacity and ability to crank the engine quickly. Today's FI engines start so quickly that the actual energy needed from the battery is very little, compared to the carbureted days of old. The shortcomings are revealed when cold, or when the compromised battery was discharged more than normal through some incident, like too much stereo with the engine off, or a dome light left on overnight.
Sure some batteries are more resistant to abuse than others, but in large part, starting batteries are all very similar, the difference is in the marketing and the sticker thrown on the case and what the battery distributor feels is the best compromise for their maximum profit.
Interstate has never manufactured a battery, they are a battery marketer. Their flooded starting batteries are largely made by Johnson controls.
Whether this JC battery with an interstate label is the same internally as the Wally world battery with an everstart Sticker on it, is the biggest unknown factor. We know WW forces manufacturers to a price point, but will manufacturers retool their lines to cut the corners to meet WW's price point, and actually still profit?
And as far as avoiding anything with a diehard label on it, well the Die Hard Platinum batteries are relabelled Odyssey AGM batteries, and these are among the best lead acid batteries available. The Die Hard Gold AGM are relabelled Deka Intimidator series, which have a pretty good reputation too.
But drain any battery to 50%, expect short drives to return it to 100%, and it will live a short life, regardless of initial build quality, or how shiny the "130 amp" alternator is.
Because getting any lead acid battery from 80% to 100% takes hours, regardless of the charging source.
