Why do batteries puff up? been using the same battery for a while and recently it started to puff up after flight.

batteries usually puffs when its over-discharged....or when the motor demands so much power that the battery cant handle, gets over-heated, than puffs. they also puff when they are about to die. its days are numbered once it puffs. now lets sing puff the magic dragon ....lol

Is it safe to use them once they start puffing? I have two that suddenly started puffing after flights - I have continued to charge and use them and they don't seem to be any different - still get the same flight times and performance out of them - They're just a little "bigger" after the flight than before the flight.

My intention is to continue using them till they die - I just don't want them bursting into flames either on the bench or in the air taking the plane out in a fire ball.

SansHeli.

many do continue to use them after they puff, some dont. For me,it depends. Ifit still charges and balances ok on the chargerthen you're good.Youcan tell when a pack is really dieing. it loses all its punch and charges quicker than normal.

Yeah and if pushed too hard, you get to see Puff's magic smoke too.....

For the OP; I'd trash 'em. You only need to see a Li-Po fire once and it should convince you not to push your luck.

here's a quickvideo of a puff battery I had recently. It was a brand new hobbymate 3800kv motor on 13T pinion. my headspeed was somewhere around 3500rpm[X(] I should of only flown for 3.5 minutes but my timer was set to 5 min.

[youtube]http://www.youtube.com/watch?v=UZpzdUpb20s[/youtube]</p>

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