There are not that many battery manufactures-in the world, yet alone in this country. They are made under contract for the retailer-per their specs. There is no such thing as one battery make is better in all instances than another. Group sizes are made differently and variables will always enter the picture. That stated when someone tells me to buy a car makers battery, I tell them what to go do with themselves.

I have even had very good luck with Walmart batteries in the past. For the large batteries such as in our X5, I prefer Interstate which I have in both of mine, and in one of my cars. Is it the best? There are those who experiences failure with Interstate, and all of the AGM batteries out there.. It just happens. Have had numerous Exide made batteries as well. But Interstate has been good to me, and they have a large network for warranty purposes-though I have not had to utilize it. I look at the specs, reserve, CCA, and warranty, and buy once I'm comfortable. BTW-I sold Exide for many years. I also try to buy a replacement every 3 years for each vehicle.

I live a few miles away from the East Penn Mfg battery plant. I buy their "blems" at the factory store and always ask them to do a carbon load test on them to confirm charge; they even print out a little ticket with the results; they come with a warranty.

The counter staff confirmed they make batteries for at least a dozen retailers but declined to name them. The blems used to be about half price, even the AGM stuff, but lately it's more like a 10% discount off retail. No branding on the case, just an ugly white sticker proclaiming "The Usable". The plant is ginormous.

I gave up on Duralast last year, the quality has gone down so much that it barely lasted 2-3y. Plus the Duralast price has gone through the roof at $130-$140/each.

I found a better alternative: EXIDE L3, which you can find at local Home depot or Menards hardware store for $90! I used Exide in my kids car (1998 Volvo S70) and it has been 3y without issues, this car parks outside and exposed to all kinds of weather!