[NSRCA-discussion] Lipo fire

John Gayer jgghome at comcast.net
Mon Jun 13 18:17:16 AKDT 2016 

Use a small wire tie to bind the balance cable to a power wire. The 
wires may still break but it should be outside the battery and 
relatively easy to fix. Also less likely to short.


On 6/13/2016 7:14 PM, Wayne Galligan via NSRCA-discussion wrote:
> Hobby People batteries are the worst for the balance leads breaking 
> loose at the solder point.  Wires to short and stiff.
> Wayne
> *From:* Chris Moon via NSRCA-discussion 
> <mailto:nsrca-discussion at lists.nsrca.org>
> *Sent:* Monday, June 13, 2016 7:43 PM
> *To:* Robert Green <mailto:robcase1 at cox.net> ; 'General pattern 
> discussion' <mailto:nsrca-discussion at lists.nsrca.org>
> *Subject:* Re: [NSRCA-discussion] Lipo fire
>
> Robert,
>
> That's a good question as there probably isn't a realistic method of 
> knowing.  All one can do is get high quality batteries (not implying 
> yours were not) as they tend to have the more flexible multi stranded 
> balance wire vs the cheaper stiffer wire that is usually put onto 
> cheaper packs. The more flexible wire will help with fatigue issues. I 
> have to tell you that I had sample packs from some factories that I 
> put outside on my concrete patio as soon as I cut the shrink wrapper 
> off of them and saw the quality of the workmanship inside, just unsafe 
> to even have sitting inside.
>
> I guess the seemingly over concerned user who keeps his packs in a 
> fire proof canister or sack may be onto something as you really can't 
> tell when a lead might break off internally and short. Alternatively, 
> you can cut off the shrink wrap and inspect new packs and then 
> reshrink wrap them with a clear shrink wrap so you can see as much 
> inside as possible.  The chances of a balance lead breaking internally 
> and shorting itself and starting a fire is admittedly minuscule but 
> the price of being wrong can be very high and I'm just glad everyone 
> there is ok.
>
> Chris
>
>
> On 6/13/2016 5:58 PM, Robert Green wrote:
>>
>> Chris,
>>
>> i would agree that this is where something happened.  I wish i knew 
>> from looking at hte pack after pulling it off the charger that 
>> something was wrong. i wonder what a good warning system would look like.
>>
>> ------------------------------------------------------------------------
>>
>> *From:*Chris Moon [mailto:cjm767driver at hotmail.com]
>> *Sent:* Monday, June 13, 2016 2:56 PM
>> *To:* Robert Green; General pattern discussion
>> *Subject:* Re: [NSRCA-discussion] Lipo fire
>>
>> Glad everyone is ok there Robert.
>>
>> I have handled and dissected hundreds of different packs during my 
>> time in business, evaluating samples etc and I can say with certainty 
>> the weakest link in our batteries are the balance leads and their 
>> connections to the individual cells. These are very thin wires that 
>> typically are spot soldered to tiny tabs on the cells and crimped 
>> into tiny pin connectors. Insulation of the balance wires inside a 
>> pack is usually a thin piece of cellophane looking tape.There is 
>> little to no strain relief for the wires and we handle and flex them 
>> every time they are charged. I have seen many break off and touch 
>> others creating sparks and possibly could have lead to fires if they 
>> were pressed together long enough.  I would bet this is what happened 
>> to Robert's pack.  The batteries themselves must pass through pretty 
>> rigorous testing including being crushed with a metal blade without 
>> catching on fire before they will be transported from China. These 
>> testing documents accompany every large battery shipment so it is 
>> highly unlikely one would spontaneously combust. With an older pack, 
>> it most definitely sounds like an internal short of balance leads.
>>
>> Chris
>>
>> On 6/13/2016 11:15 AM, Robert Green via NSRCA-discussion wrote:
>>
>>> Hey guys wanted to let you know about an incident I had over the 
>>> weekend that caused some high concern.  I flew four flights 
>>> yesterday, then returned home.  I thought I would go back out later 
>>> and fly three more, so I charged three more batteries.  The three 
>>> batteries on was planning on using, were flown the previous day, and 
>>> were not overly discharged.  I took my kids to the movies as my wife 
>>> did not want to go, and that turned out to be the best thing for the 
>>> family.  One of my 2014 packs decided that it no longer wanted to 
>>> live and decided to catch fire all by itself.  I have always thought 
>>> that the best time for these to catch fire, would be during the 
>>> charge cycle.  This incident happened almost an hour after charging 
>>> the pack.  Keep in mind that after I charged the pack, there were 
>>> immediately put into my flight box for storage until I got back from 
>>> the movies. After I took them off the charger, the batteries did not 
>>> see warm in any way, cool to the touch.  I have had these batteries 
>>> for two and as far as I can remember - they where not damaged in any 
>>> way.  Due to my wifes' heroic action, the house did not catch on 
>>> fire like my toolbox did.  She brought them out to the drive way 
>>> water on them to kill the flames.  I have been pretty cavalier with 
>>> packs, leaving them out once they are charged and not putting them 
>>> in something safe for storage....those days are done.  If this can 
>>> happen to a battery sitting with a stored charge, I will not longer 
>>> leave my house or family unprotected.
>>>
>>> I bought a safe yesterday, but apparently that may not be the best 
>>> thing for them either as the battery give off a gas and they need to 
>>> breathe.  In other words if you left them in a safe you may be 
>>> creating a bomb scenario. What I did was - several years ago, I 
>>> bought a metal ammo case.  I removed 3/4 of the rubber around the 
>>> case allowing for the exchange of air to occur.
>>>
>>> If any one has any other creative ideas on how they store there 
>>> lipos, please contribute to this thread as I think it is important 
>>> as a community that we spread the message that this technology which 
>>> has been proven to be safe for the most part also can be dangerous.
>>>
>>> thanks,
>>>
>>> Robert
>>>
>>>
>>>
>>>
>>> _______________________________________________
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>>> NSRCA-discussion at lists.nsrca.org 
>>> <mailto:NSRCA-discussion at lists.nsrca.org>
>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>
>
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