I charged the battery on my dad’s 1994 Honda 300 and drove fro about an hour. After killing the engine I turned the key back on to check to see if the battery had enough power to crank.

When i hit the starter button a shot sound about as loud as a 22 rifle come from the under the seat and a small amount of smoke came from the battery case. Now with the key on their is no power.

I opened the battery case and the battery looks ok and I did not see any melted wires.

Any ideas on what happened?

Thanks.