A previous poster mentioned Autozone Duralast battery warranty - warranty on the red ones is 2 years free, 5 years prorated; gold ones are 3 free, 5 prorated. If replaced free, the warranty term is the remaining term on your original purchase. If you get a prorated battery, you get the full new warranty term, and you pay based on the original price on the battery, not the current price. That may be a $30 difference in your favor! If an employee tells you different, ask for the manager.
As a former AZ employee, I can say I probably sold a thousand batteries and replaced 200 under warranty. (just guessing!) Is that good performance? I don't know, but the warranty replacement is no questions asked, no hassle. If you have a wierd problem with your truck (like killing 3 batteries in a year while the charging system tests good), well, 3 replacements is about all you'll get before they tell you to get your junk diagnosed by a profesional. But they're probably right and that's not a bad deal overall.
Another warranty note: if you buy an AZ battery, your info is stored by phone number and name in their computer system, accessible from any store anywhere. You don't need a receipt. If you change phone numbers, drop by a store and have them change the records on your previous pruchases before you forget the old number!
Warranty is not transferrable. If you buy a truck with batteries under warranty, ask the seller for the phone number he uses for his warranty, and note that with his name. Write it on the batteries with a sharpie. If they go bad, pretend you're him and you'll get his warranty. Obviously the name on your credit card won't match his; if anyone notices, just tell them it's your friend's truck and you're fixing it for him.
Have you ever bought a battery and not turned in a core? That info is all in the computer too. Want beer money? Find a junk battery and turn it in for your 5-year-old core charge refund! I've taken lawnmower battery cores on car batteries. As long as there's something to put the barcode sticker on, it doesn't matter. YMMV, but ask for a manager if you don't get what you want.
My truck came with fresh Interstates, and so did my golf cart, but when replacement time comes, I'll probably shop at Autozone... As I said, I am a FORMER employee and not a stockholder. I get no benefit from anything I just wrote. It's a sucky place to work, but not a bad place to buy parts.
I saw an informative article on charging Optima batteries. I don't have a link to it right now, but if your Optima is dead and won't take a charge, hook your charger to a regular battery, then run jumper cables from the regular battery to your Optima. Apparently battery chargers often can't "see" a dead Optima and won't turn on!
HTH a little.
kevin