I had an alternator fail about 60 miles from home in the morning. I turned around, shut off as much electronics as I could. When I was about 2 miles from home, we had a downpour. The wipers would barely move. Once home, I charged the battery overnight with a 6A charger. The next morning, the car wouldn't even crank.
So, I headed down to Advance Auto parts with my 35 month-old battery. The guy tested it and said it needed to be charged. I told him that I charged it over night with a 6A charger. He told me that 'Those Things' won't charge a battery. And, I said "Then why do you (they) call them battery chargers?"
He also told me that he wouldn't honor the warranty, so I went to the next closest Advance place, and they exchanged the $125 battery with no questions asked.
The only thing that I didn't do before I charged it was measure the battery voltage. After the overnight charge, it measured 10.7 VDC, so I assume that one cell had shorted out. Since the newer batteries didn't have the caps to check/add electrolyte, I couldn't measure the specific gravity on each cell to determine the failing cell... Ron