Most batteries on the market are manufactured by only a few companies, regardless whose name is on them. Johnson Controls Inc. and Exide are the two big players, with Johnson Controls being the top dog. JCI produces batteries for Autozone, O'Reillys, Advance Auto, Wal-Mart, Sears, Interstate, AC Delco, plus oem batteries for the Big 3. They also own Optima. Exide makes TSC and Napa. Pretty much all lead/acid battery manufacturing has moved to Mexico, due to EPA regulations, though some specialty batteries are being made in the US again (Optima, Enersys).
