Hi, I am posting this on behalf of my boyfriend and we are both fairly inexperienced with boat mechanics. We tried to start the boat up for the first time since the winter and are having issues. When turnin the key power is being received by the stero, fish finder, leg lifts but it won't turn over or start. Also the negative on the battery gets really hot and begins to smoke/ spark. We have cleaned the battery posts, terminals etc and no luck. Not sure what to try next as we have googled the problem and seems like there could be many seperate issues causing the problem. Can anyone suggest what we could check next to narrow it down or anyone have had this issue themselves? Thanks in advance.