So, what does Sears propose to do with a 100 month battery that died at 64 months? If they're not going to pro-rate it, then they should completely replace at no expense.
And as far as I'm concerned, they may have a new policy on batteries that you buy today, but they still have to honor the warranty that you paid for - you paid for the warranty, not just the battery.
I had them try the same thing on me with some taps. I took two in to be replaced and they said taps no longer had a lifetime warranty. I said show me, so we opened up a set, and that's what the paperwork said. However, the rest of story was that they had given the new taps a new part number. The lifetime warranty still applied to my older part numbered taps as far as I was concerned. After a lot of arguing, they had to agree with me and gave me new taps. And of course the new taps had the new part numbers without a lifetime warranty.......
Bill