Yesterday evening I attempted to start my generator to let it run and get some stabilized fuel in the lines and carb. The second I hit the start button from inside the cabin at the panel, I hear a very loud bang that scared the &@€* out of me. Couldn't get up those stairs fast enough, open the main access hatch to see and smell acrid smoke and acid. The generator battery EXPLODED!! There were battery parts and acid everywhere. Took a couple of hours with a baking soda and distilled water solution to get it all cleaned up. My question is just how common is this? One piece of the battery top shows that it was a deep cycle battery, why wouldn't that battery have been a starting battery?