there are bout 6 battery manufactures in the US, they make all the batteries. They all make good and cheap batteries and brand them for specific buyers. Most chains (costco, walmart, car parts store of your choice) wont even have the same battery manufacture at all locations. They often wont even use the same one year to year. Depending on location its often cheaper to buy from the manufacture closer to you. So just a "example" Store A in Washington will get its batteries from a California manufacture, while Same Store chain in Texas will get its from a Oklahoma manufacture who is not affiliated with the one in California. They use the same branding, but are made different inside. SO in the end its possible the Walmart battery is the same one Costco sells, or Advanced auto depending on locations. Dont expect the high end Walmart battery to match the low end one someplace else, but its possible the $99 Walmart battery thats 800 CCA is the same as the Advanced auto one that's 800CCA for $120. All this info is out there (google) but is not going to appear on the first page, you do have to dig a little. I have had TERRIBLE luck with walmart batteries, but they have a 5 year warranty , 3 years free replacement (if you buy the best ones they have, and they are generally $30-60 less then the best from others), in the last few years i have had to replace 3-4 of them, but its always been free.. so I cant say I have been screwed, but i have had to take them out and replace them. I used DELCO for years and had good luck but they dont seem to be around anymore. If you read reviews, it seems DIE HARDS from sears are almost always rated high and not horrible priced. I know many guys who swear by Optima's too, but 2X the price of most battires I have never bought one. My truck has a 10 year old Roadrunner in it (fleet farm) that has started the truck in 30 below and such for 10 ND winters.. it was a cheap azz 600 CCA that i payed $49 for. Some mention Interstate, they are one of the manufactures, so they should (you would think) make the best for themselves.. never bought one as they are also about $60 more then walmart (but maybe i should). I think its a bit of crap shoot, you got a good one at STORE X last year doesnt mean it will be the same this year.