Li-Po fire!

[Dedcalm]

Mate was flying his Li-Po (1600mah) powered Zoom400 heli the other evening and after about 30-60 seconds of flight power dropped off so he landed it. Battery pack was making a squeeking noise then started smoking and as he backed off it turned the Zoom400 into a Roman Candle! 4ft flames!
Luckily the damage to the Zoom was only a few parts, 3 servo's, Rx & Gyro and is being repaired currently.

I have heard that Li-Po can catch fire if charged incorrectly but have not heard of fire during after discharge.

Rob

[Raptorite]

Hi Rob,

At the 3d masters this year the comentator (I forget his name) was talking facts and figures about the various electric helis being demonstrated, two in particular were the Heinseleit 3DMP and the Mikado logo.

During these demo's the chap was saying that the optimum running conditions for these li-po cells is to be maintained at a constant 20 degrees celsius before flight and during flight they heat up to about 60 degrees celsius under normal load. He then went on to say that they were actually too hot to be handled for at least 20 minutes after the flight

From that point of view I am not entirely surprised to hear of one catch fire during usage, quite apart from the inherant risks involved in the charging process !

Personally I think that if these li-po's are so good at storing and releasing such huge amounts of power in a short amount of time, why do they get so hot, surely lots of the stored engery is being wasted in generating all that heat.

My zoom does have lithium cells, but these are lithium-Ion's not the more volatile polymers, they probably dont give quite the same amount of punch that the polymers do, but from what little flying Ive done with it so far thats fine with me.

Cheers,

Pete.

[Dedcalm]

I agree that they must be wasting energy as heat but then all cells heat up during high current drain so guess it is "normal". Li-Po is new technology so I guess it will improve over time, as all things do.

Interestingly the chap saw smoke and backed off before it turned firework, some people may be tempted to try to save their heli/plank and this could cause serious injury.

I believe that the contents are prone to fire is exposed to air which would explain the metal bag that they sit in, maybe vibration wore a hole ?!?!?

Rob