I bought 2 group 31 platinum diehards March 2013. had to have both of them replaced last week. One of them would not hold a charge under load, and on the second battery, the negative post cracked off inside the battery and was visibly loose on top at the clamp, second battery also had a crack on the top of the case that had liquid bubbling from inside the battery.
Great part was i called the closest sear to me, asked them to put 2 batteries aside for me as i would be down over the next few days. As it turned out i was able to make the drive (about 1.5 hrs) the following day. Sure enough the batteries were put aside with my name on them, the guy at the counter filled out the return/exchange paperwork, and i was on my way with the new batteries. What surprised was that they didn't even test the batteries i was returning…they took my word on the condition of the batteries.
Also something of interest, i was told that my warranty was still based on the original purchase date, but if i had another problem with the batteries within the original 3 yr period, i could come back, pay a pro-rated amount, and the warranty would start all over again. Now i hope that isn't necessary, but with the amount of electronics in my truck, it wouldn't surprise if these batteries have a short life as well.
dealing with sears was easy, i think it is the first time that i didn't get screwed by some fine print
very pleased overall with my experience.