A battery that doesn't get cycled frequently, or is left in a discharged condition for a long period of time forms crystals of lead sulfate on the plates. That's not normal, as the spongy lead sulfate that forms during normal discharge recombines into the acid easily when the battery is recharged. Sulfate crystals are extremely hard to re-dissolve and they reduce the reserve capacity of the battery by weakening the acid concentration. A sulfated battery absolutely will not pass a high-discharge load test.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!