Diehard is a premium brand of automotive battery marketed by Sears Holdings Corporation. A small variety of cars, the most popular kind of automobile. ... Four double-A (AA) batteries In science and technology, a battery is a device that stores energy and makes it available in an electrical form. ... Sears Holdings Corporation (NASDAQ: SHLD) is the third largest retailer in the United States, behind Wal-Mart and The Home Depot. ...

The brand dates to the 1960s. In its earliest years, the brand was guaranteed to last "forever", that is, as long as the original owner still owned the car in which it was originally installed, far more generous than traditional pro rata battery warranties. When drivers began to keep automobiles for longer periods than had been traditional previously (due to both their rising cost and hence longer financing contracts, and their improved durability), the cost of this policy became prohibitive and it was discontinued. However the brand line was kept and expanded; it now includes medium-priced, medium-duty batteries as well as the premium-priced, heavy duty line with which it was begun., and in recent years has been expanded to include other, non-automotive batteries as well. The 1960s, or The Sixties, in its most obvious sense refers to the decade between 1960 and 1969, but the expression has taken on a wider meaning over the past twenty years. ... In business, a warranty is a guarantee of the reliability of a product. ...

Diehard is also the name of a random number generator test suite http://www.stat.fsu.edu/pub/diehard/