My wife's car has been in storage for a month or so & the battery died. I bought a die hard brand automatic battery maintenance box, hooked it up & got no blinking lights. According to the manual, the most likely cause is a dead cell & it recommends I have the battery checked. Before I yank the battery & drag it to autozone, is it really possible that a cell went bad already? Or did I maybe get a bunk maintainer box? The battery is only about 3 years old, duralast brand & it's never had problems before. What are the odds on this? Thanks!