I was charging my vision spinner 2 at work. And i left it unattended for maybe an hour. When i got back to it it was so hot that i couldnt touch it and the plastic of the charger was melting! I unplugged as fast as i could and once it cooled down i noticed some of the juice had leaked onto the battery and was burnt pitch black. Im assuming that this was the cause of a possible short circuit. just wanted to give you guys fair warning to check for any juice on the battery before charging. Who knows what would have happened had i got there later than i did