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Slightly puffed Lipolys??

Old 10-04-2011, 10:45 AM
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av8tor1977
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Default Slightly puffed Lipolys??

Please forgive me if this has been covered before, I did a search and didn't find anything....

I have 5 LiPoly batteries that are only 4 months old, but I had to be away from home this summer, and it got so hot in the house that they are slightly puffed. (Yeah, I know, incredible huh??!!)

Anyway, I have had Lipoly batteries in this condition before, and they won't hold up to a flying discharge rate. I can cycle them on my Accu-Cycle Elite drawing 300 mah, and they show normal capacity. But if you put them in an airplane pulling say 10 or 15C and they go flat in short order.

So, my question is since they do hold up for a lower discharge rate, would they be ok to use as a flight pack in a glow or gas powered plane??? Or are they just plain trashed, done deal?

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AV8TOR
Old 10-05-2011, 04:10 AM
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aeajr
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Default RE: Slightly puffed Lipolys??

A hot house should not damage your battery packs. Even in Death Valley I would not expect a hot house to damage Lipo packs.

Not sure how slight is slightly puffed. But puffing, in my experience is caused bydrawing the packs at or over their C rate, running them too low too often or getting them out of balance which causes over charging in some of the cells.

But putting that aside, if the puffing is SLIGHT and they seem to have their rated capacity but can't deliver their C rated currents reliably something has caused them to rise in internal resistence. That would make me suspect their reliability.

You could probably use them as bench packs for radio set-up or perhaps to drive a field charger but I would not rely on them for a receiver pack in any plane I value. You just don't know what is going on inside and if they fail .... by by airplane.
Old 10-05-2011, 09:39 AM
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av8tor1977
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Default RE: Slightly puffed Lipolys??

Well, I can assure you that's what happened. These batteries have never been "overdrawn" in current because they are receiver/servo flight packs. All of them were fine the last time I charged them, before leaving the house for the summer. Upon returning, all my batteries in a cooler chest on the cool(er) kitchen floor were fine. All the battery packs that were in the airplanes are puffed up.

It can hit 120 degrees here, and an un-airconditioned house could conceiveably hit 140 degrees or more inside, which would be enough to hurt the batteries. Upon arriving home I also found candles that were melted. A friend of mine lost a bunch of batteries the same way last summer. The batteries were in his large travel trailer that he had converted into a workshop.

Anyway, you are right. It is not worth chancing using them in a plane... Bummer! []

Thanks,
AV8TOR
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Old 10-05-2011, 05:37 PM
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Default RE: Slightly puffed Lipolys??

You learn something new every day.

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