This is true, however some manufactures pay for the ones that test better. When I was around 20 years old I worked at a factory making shop vacs for sears and home depot, the sears branded ones the electric motor had to test above a certain level, all of those below that were put on the Ridgid branded ones.
I could have bought a duracell battery at Sams Club that was identical to the sears battery for much less money, but knowing the above I chose to spend the money on the name brand. Both even have the same warranty.
Duracell AGM Automotive Battery - Group Size 47 (H5) - Sam's Club
Sears.com
