Walmart Batteries: Our area Walmarts were selling Exide manufactured batteries, while other parts of the country were getting ones from Johnson Controls.
About 8 years ago I bought a Johnson Controls battery from Walmart, it still is working well in my ski-boat, even though it was the cheapie one year warranty battery. Then our local store began stocking Exides, of course all those that I have bought have corroded the terminals, failed very early, etc.
Our luck has changed, our local walmart is again stocking Johnson Controls batteries. Their batteries have always listed the manufacturer on the label....
You can also tell with a charger and a digital voltmeter, Exides are lead-antimony construction, and the J.C. batteries are lead-calcium. All the manufacturers, except Exide, have switched to lead-calcium, and the differences are clear on your digital voltmeter....I have posted the info on a previous post.