This is kinda CPR on an old thread, but I think it might be useful... On 4/15/2023 I looked at a bunch of batteries on the WalMart rack in Butte MT, and all were JCI serial.
I swap batteries around in my "fleet" with the things that "have" to start - regardless (primary vehicles, fire pump) getting the new ones about every 5 years, and doing my best to use what's left of the uncertain life of batteries among the rest of my uses (local and property vehicles, backup generators, battery backups). I've come close to getting everything to be able to use a 34/78 dual terminal one way or another. My old Chevy Lumina with the washer reservoir formed around the side terminal (only) battery, and the new Ford Fusion with the short battery shoved under the windshield, are irritating exceptions. There's really no need for either and think about how much better off we'd all be if there was one mass produced battery that fit all of our ICE vehicles!
I don't know what was going on in the early years of this century with Costco and their batteries, but I recently turned in a 34/78 battery that did 10+ years of abusive good service (plus another 7+ years of scraping by), and today I decided to keep another Costco battery because it passed a load test (28 f) and still started my (property only) truck - placed in service in 2004! These had 100 month warranties, and I believe they were EP batteries. I wish I could by a few more of those. Costco is now Interstate.
Today I settled for a JC 78 series 600 CCA Value cheapie from WM, and an Exide brand of 34/78 DT 800 CCA from the ranch store that was having a 20% off sale - $58 and $71 respectively. I might be my own worst enemy in trying to get quality products on the market! The problem is that the selection is limited in my market, I can't pay more than double for something not twice as good, and what I bought I think will work for their intended application (the cheapie batt is going in an end of life vehicle, and because it isn't DT, I can't swap it out),
The two batteries I purchased today were to replace a 9 year old Exide brand that suddenly leaked and died. That battery was the one that replaced another Exide (I believe) brand that also leaked and had proactively replaced the Costco battery from 2004 that was granted a stay of execution today since it was still working perfectly. The other battery is to rotate back a 9 year old Exide brand that is still going strong, but is in a role too critical for its age. I can't really fault the batteries dying, but I could do without the leaking!
Thinking back, I don't think I've had a life or leakage disappointment with the EP batteries, and that says a lot, because I run them to the bitter end, and leaks, especially, are a PITA. I was hoping to buy at least one today, but also having other things to do, I had to settle for what I could find. Batteries are a mixed lot, but from what I can see, there are differences in what's on the market. I believe that EP is making a quality product,