I have never--"never"--had a WalMart battery outlast it's warranty period. They ALWAYS fail before the warranty expires. Some might consider this an advantage because you get a free replacement. The problem is that most people, like me, lose their receipts. WalMart will not honor their warranty. They even print the date of manufacture on the battery. But if you don't have a receipt, even if the battery fails before the date of manufacture, WalMart won't honor it's commitment.
So, I am done buying WalMart batteries. I took my expired battery to the WalMart in Grand Junction, Colorado tonight, March 6, 2009. The battery was clearly dead. The date of manufacture was less than three years ago. But WalMart would not replace the battery.
I put my battery back in my shopping cart, and determined to never buy another battery again from WalMart.
By the way, they do the same thing with tires. They change the brand of tires every couple years, so when your tire wears out, they don't have an equivalent replacement. I wound up paying extra to "upgrade" my worn tires, because they no longer carry my originally purchased tire brand.
Review about: Walmart Replacement.
Monetary Loss: $75.