Car batteries have become commodities. Good/Better/Best product segments for each application, differentiated by cosmetics, brand labels and warranty terms from retailer to retailer.
The handful of the largest manufacturers will produce them in whatever factory makes the most sense to them at that point in time, whether in-house, or a joint venture, especially for a company with global reach like Clarios (remember their Saudi-made batteries from a few years back? Also joined in the past by Germany and Spain.).
A big marketing and distribution company like Interstate chooses from those suppliers for whatever applications they wish to cover; they've been a big JCI customer in the past, but now one can see the Exide and Enersys batteries in their offerings.
Retailers like Walmart and Costco do the same, by either going directly to the manufacturers, or engaging with another distributor like Costco does with Interstate.
The result can be multiple layers of middlemen, which adds to the muddiness of the waters surrounding who made/got what, from whom, etc.
The only certainty is to look at what sits on the rack in front of you, courtesy of whatever the regional distribution chain provides, at the particular point in time, because it's likely to change at some point in the future, to suit whatever the supplier can and does deliver.