The majority of car batteries are created by 3 manufacturers - Delphi, Exide and Johnson Controls Industries. Delphi makes some EverStart models sold in Walmart and ACDelco. Johnson Control Industries makes Duralast seen in Autozone stores, Diehard - sold in Sears, Kirkland - the Costco brand, Motorcraft - which Ford sells, some of the EverStarts, and Interstate. Exide makes Exide batteries, Champion, Napa and even a % of the EverStart batteries.
Johnson controls they are sold in wallmart As of April, 2010, East Penn makes all the Everstart batteries - at least in the Northeast stores.
Excide makes their batteries at this moment 11/2013.
Bosch
The OEM batteries for Audi are either Varta or Moll.
Johnson Controls
East penn
Johnson Controls Inc. makes AutoCraft Gold Battery, OPTIMA, Interstate, Motorcraft, & Energizer car batteries.
Johnson Controls inc
Johnson Controls
Exide
Interstate Battery Company
Interstate is a battery company making their own batteries since 1950.