Took the quad out for a test hop a little bit ago. It was too dark, so I just went up and hovered, checked controls for a few secs and landed. Picked up the quad, unplugged everything and set it on one of our deck tables. A short time (with a minute (?) I hear a distinct, "PFFFFFFFFFTTTTT!" turned my head and the battery was off gassing. I grabbed the quad, ripped off the battery and threw it into the yard. Here's the result. It is quite painful. Be careful out there!