ok, my friend crashed his T-Rex 700 and severely deformed his on-board lipo battery. However, there was no leaked. He decided that the battery is done because it might explode while charging.

So we came up with the idea of trying to make the lipo catch on fire. Not a smart idea. We removed the dean's connector and connected the positive and the negative together and then threw it pretty far. Seconds after, we saw a tiny bit of smoke and then that was it. Nothing after all. We walked close to the battery 30 minutes after, it was just sitting there looking like a normal lipo.

We thought maybe there's some kind of internal protection thing that automatically disconnects when temperature reaches certain point.

We were expecting at least a little fire, but instead it was only a tiny bit smoke.

Sounds like you're trying to hurt yourself.

It was one of my friends, he's one of those guys that likes these dangerous act. Me and my other smarter friends were standing way back watching him.

LOL, nothing wrong with a little fun though

im geussing the batt had internal dammage so not a lot happened,

the lug

If you are into doing dangerous / stupid stuff, you could always microwave it like these guys did:

http://www.youtube.com/watch?v=BRwyiR-FnhQ

Stay safe... always safety first

That is really dangerous and stupid.

What might have actually happened was that as the battery was shorted, the wires, solder tabs, etc. became so hot, the solder melted and they become disconnected, interrupting the short. In essence, the person who was shorting it out 'got lucky', since it could have burned his hands or vented before he threw it.

but it shouldnt catch on fire so fast right? I had an incident when the dean connector on my lipo came off during landing. I didnt know what happened when the truck stopped running. So I walked over and saw that the positive and negative were touching and there were some sparks too. From the time it shorted to the time I walked over was at least 10 seconds. I just separate the wires and have been using that lipo for months now without any problems.

If there were sparks, it is a sign that the connection between the (touching) wires might not have been that good. If the wires weren't hot when you seperated them, that is another indication that not a great deal of current was traveling though them.

Too many "it depends" things, no two shorting events are going to be the same and it's hard to come up with rules as to what is going to happen, other than just saying "Don't do it" or "avoid it if possible".

my thoughts exactally

the lug

I'm suprized the door didnt blow off the microwave? People really do stupid things with Lipo's after they are toast, because
once they are swolen you cant ship them back, heck would anyone want to in the first place.

One of the guys at the track took a swolen lipo and took a BB gun to it, it shot flames 2FT in the air.[X(]
We were at a safe distance so nobody was injured. whatever you do, dont charge a lipo on the nimh setting either, it will puff.

I've had a couple of helicopter lipo's short out, once in my pocket trying to warm it up on a cold day.the balance tap wires came apart!!.. thankfully it was a smaller capacity pack but it was 3S.. I felt the heat of the wires before anything "blew" up and quickly took the battery out of my pocket.. The battery was no good after that.. something internal shorted but the battery did not blow up or even puff... wasn't worth trying to fix it.. the helicopter cost alot more than the battery and I wasn't going to risk it... I've seen a few video's on lipo fires and most seem to be from over charging or compromising the battery.. ( breaking the silver foil).. seems that air reacts violently with the lithium in the battery and causes a fire...

That is true for any alkali metal, just be glad it is not potassium or cesium... lithium is the least reactive (relatively) out of all those metals.

Though in a normal LiPo under typical conditions, I think the Lithium is in ion form so it's not terribly reactive. If you overcharge it, that's when you start to get actual lithium in the metal form.