Yesterday I fueled the bike up for a ride. When I went to start it, it started but something did not sound right so I shut it off. I tried to restart it but it wouldn't start and the starter would not shut off. I turned the key off and hit the kill switch and still the starter kept turning over. I was in the process of removing the seat to disconnect the battery when the battery finally gave up. First time I've ever trailered my bike, I wasn't happy. I brought it home and threw the battery tender on it and left for the day. Came home later and it fired right up like nothing ever happened. Any ideas what happened or what to look for?