[NSRCA-discussion] Battery puffing question?

[Stuart Chale]

Puffing only at too low a voltage is info I received from a 
manufacturer.  Not sure if it is fact or just a way for them not to 
uphold their warranty  :)
I have had cells fail in my pattern packs but never by puffing.
I have had a few indoor packs puff after sitting around for a long 
time.  Unsure if they were charged or not prior to sitting.
Stuart

Verne Koester wrote:
> Stuart,
> I've had cells puff with the pack just sitting on the bench. In one 
> case, the pack was brand new and I hadn't even soldered a connector to 
> it yet. I checked the voltage and it was about 19.5v on a 5-cell,. 
> Another time was my fault when I left a pack fully charged for about a 
> month because of lousy weather at the end of last season. The 
> manufacturer replaced both of those packs at no charge.
>
> In any event, with what Anthony described, I don't think I'd tempt 
> fate by putting a charger on it.
>
> Verne Koester
>
>
> ----- Original Message ----- From: "Stuart Chale" <schale at optonline.net>
> To: <aabdu at sbcglobal.net>; "General pattern discussion" 
> <nsrca-discussion at lists.nsrca.org>
> Sent: Saturday, November 01, 2008 6:40 PM
> Subject: Re: [NSRCA-discussion] Battery puffing question?
>
>
>> As lipos get older and weaker (we then push them harder) they will 
>> tend to swell a bit when hot but should return to normal when cool.  
>> If they stay puffed up then at least 1 cell has gone bad.  I have 
>> been told that cells only puff when they are flown to too low a 
>> voltage.  If always kept at 3.6/3.7 per cell at the end of the 
>> flight, 80% or so of usable power, then they should not puff.  They 
>> still may weaken and fail but shouldn't puff up.  Are you sure that 
>> you charged the pack before flying?  That would be the quickest way 
>> to go well below the safe voltage limit.  Flying 2 flights without 
>> recharging :)
>>
>> Stuart Chale
>>
>>
>> Anthony Abdullah wrote:
>>> I have a Zippy-H 2200mah 3S pack that I use in a small electric 
>>> plane. I was flying it today and it the plane lost power pretty 
>>> quickly. I landed and noticed that the battery had puffed on me. It 
>>> was warm to the touch but not hot. I let it cool but it is still a 
>>> little puffy almost like a ziplock bag with a little air in it.
>>>
>>> Question: Should I try to cycle the pack or just chuck it and move 
>>> on? Are Lipos kaput once they puff or can they still be used? I 
>>> didn't abuse the pack and it barely flew long enough to warm up.
>>>
>>> Thanks for any info and suggestions.
>>> Anthony
>>>
>>> _______________________________________________
>>> NSRCA-discussion mailing list
>>> NSRCA-discussion at lists.nsrca.org
>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>>
>>>
>>>
>>
>> _______________________________________________
>> NSRCA-discussion mailing list
>> NSRCA-discussion at lists.nsrca.org
>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>
>
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>
>