I bought a 2001 Yamaha V star 100 Classic about a month and a half ago. I've been learning to ride and last Saturday I took my longest ride yet (about 150 miles that day) with my father in-law. We had just split ways and I was headed home. Going about 60 down the highway when I notice my speedometer is jumping all around. The motor was still running fine. As I'm watching the speedometer I notice the odometer and gauge light blinking on and off. I pull off the freeway. I took the battery cover off and the brand new battery was bulging and steaming. I quickly took it out. Towed bike home and am now wondering what's next. I'm brand new to motorcycles. What should I do to diagnose it? I don't know if it was just a bad battery? I think it's probably an overcharging issue from something in the electrical system. Where should I start? Let me say, I'm on a tight budget (I did just buy a motorcycle!) and I really want to find the problem using the cheapest option available. I don't want to pay to have it diagnosed if it's just a bad battery, but I don't want to ruin another battery if it's something else...where should I start? Hopefully, I don't sound too stupid. Any help would be greatly appreciated.