I go directly to my local Interstate warehouse and can usually buy "blems" for about 2/3 the regular price. Most of them have a scratch in the case, a little piece torn off of one of the stickers, or a small nick in one of the lead terminal posts - some kind of minor cosmetic "issue" that has no effect on their performance, and they come with the standard 3 year warranty.Many of us here that are Costco members already know this, but the Costco warehouses sell Interstate batteries with a 3 year, no questions asked free replacement policy. [That REALLY made a big difference when I had to replace
the 2 batteries in my 2002 Ford Power stroke diesel truck.] I believe their price is better than about any other place that sells batteries.
I've always had good luck with Interstate, and the "show up with your old battery and your card and here's a new [or 2] battery" is pretty much a no brainer- as long as it's within the 3 year period.
Buckshot Bill
I buy ALL my vehicle batteries there.