Well, batteries are not meant to sit on a bench for months at a time, and without being in a car or on a charger, they will self-discharge. If they sit too long and their voltage gets too low, they 'sulfate' and are essentially ruined internally.

Charge the battery for a day without running the car. Then, still without starting the car, measure the voltage. If it is not 12-14 volts, the battery is not good, although it may be 'new' in age.

Thanks Jim. I am going to put it on the charger tonight. I'll let you know what happens.

Thanks again for the info.