I purchased my boat at the beginning of last season - new deep cycle battery (wet cell) connected to an alternator on the Atomic 4. No electronics- just nav lights and a few cabin lights. No problems last year with battery. I stored it in my basement over the winter. I charged it up last month - used an automatic 2A/10A charger. Put it in the boat and it started the boat fine. The next time I went to start the boat - it would operate the blower but would not start the motor. I started the motor with a portable power source, ran the motor for a while hoping the alternator would charge it up, but still no luck. Is this battery toast?