12V battery

Be very careful when handling electronics. Especially higher voltage stuff like the 12V battery I was connecting components to last week... hehe.. some wires came loose while I was adjusting the position of the vehicle and somehow touched. Those 2 wires were the ones coming right out of the battery terminals. Whoa, you could see the sparks as the wires touched, and some smoke instantly as the rubber on the thin wires melted away. A quick-thinking moment belied urgency of the matter and I decided my body resistance was way higher than that to be shocked, but I had discounted the amout of heat generated by the short-circuiting wires. A grab with my left hand failed to dislodge the wires (when 2 wires short-circuit they are held together by a force that is roughly proportional to the increasing current passing through them). Another tug with my right hand, but to no avail. Finally I grabbed the pliers (with rubber-coated arms) and pulled. The black wire broke near the battery terminal. Perhaps it was my exertion of force. Perhaps it was the wire itself melting due to the intense heat. Almost all the rubber had gone by now (just a few seconds; definitely less than half a minute), leaving the exposed connecting wires. I guess it was a combination of my tugging and the wire itself starting to melt. If the battery got too hot (ie if the wires were thicker and hence could hold lots of current) it may have exploded.

So, be careful about exposed contacts. In fact, be doubly careful, as even if you've been singly careful it may not be enough.

I ended up with a minor laceration on my right index finger and a little bit of scald-lke swelling on my left index finger. And our project and all were still very much intact.