this might sound stupid...but did you read the directions on properly filling and charging the battery the 1st time.... Apparently, most people do not and the batteries will not last.... THIS COMING FROM THE WALMART GUY....
Most people, just take them home, fill them up with the acid and charge them, that's not the way you should do it....
Step one.... fill with acid... allow acid to sit for atleast one full hour...
Step two.... check acid level, fill to proper level....
Step three.... your 1st full charge should be done on a motorcycle trickle charger.
I think that's what the directions stated...regardless... read the directions and follow them... When the Walmart guy told me that, I ended up buying a $17.00 motor cycle charger... I will say, I haven't had any problems with the battery all season...