# what was that popping sound GP3300



## RCMits (Jan 1, 1970)

i charge 3300's no problem.. day in n day out from week to week. i cycle them, i have my own style, and it works great for my stock racing schedule.

soo......tonight.....

i never heard this sound before. i found some 2 older 3300's laying around that haven't seen a charger for about 5 months. 

i did a lower flat charge on them on my T30 at 5amps with a .03/.05 cutoff. at about the 29 minute mark, the temperature was about 108 degrees and i thought i heard a small crystalized sounding crack.... thought it was something outside as im charging near a window.

at about the 33 minute mark, the temperature was about 114 degrees and i heard another crackle sound, and then another. i took it off the charger at about 36 minutes with a temp of 118.

what da heck was the crackling sound?! scared me.. didnt see anything leaking or burned.. i've never heard it before... :| maybe im just being super paranoid from the lack of sleep. maybe i just never payed attention.. cuz usually my house has alot of noise... today its VERY quiet....LOL.

hmmm...


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## lazerpunk (Mar 2, 2005)

The last time I heard that was when a friend was charging on his older T-30 and it did not detect a peak and kept on charging. We heard the sound everyone looked around, found the problem and then it sounded like a shotgun going off when the battery exploded and put a hole in the drywall with one of the cells.. So be carefull.


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## eri3f0g (Feb 12, 2004)

I have had a similar experience with some of my older packs. (honestly due to my budget most of my packs are becoming 'older') Mine would do that pop during normal charging but as you stated the temps weren't out of line. I would then put them on my discharger with a 20+ load on them and thats when I could see the "one" cell that was the culprit. On a full discharge from being peaked one of the cells would run about 20degrees higher. I disassembled the pack, removed the culprit, and installed another one and my problem was solved. 


If I was to speculate I would say that the crackle/pop is the cell preparing to vent or mildly venting.


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## RCMits (Jan 1, 1970)

lazerpunk said:


> The last time I heard that was when a friend was charging on his older T-30 and it did not detect a peak and kept on charging. We heard the sound everyone looked around, found the problem and then it sounded like a shotgun going off when the battery exploded and put a hole in the drywall with one of the cells.. So be carefull.


oh it wasnt like a shotgun crackle loud, it sounded mildly like someone stepping on glass 30 feet away, but none-the-less it sounded odd. maybe it was venting and just "re-crystalizing" or something other... 

discharged it before going to bed, and ran one cycle this morning before work, and it didnt do it... but one cell felt a bit warmer than the others. 

maybe its just older pack trying to jump back to life.


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## tommckay (Sep 26, 2001)

I had a stick pack do that the last time I charged it. it is scary thinking it might go Boom! I took mine off the charger & let them rest then peaked them on my best charger. They performed great... still a little worried about them though.


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## RCMits (Jan 1, 1970)

FYI, i cycled it at 4 amps... yeah i know low... 2 times, and then did it at the normal 6 amps.. no more sound. i think it was just cuz they were sitting around for ages.. i dunno.. *shudder*

anyone wanna donate some new cells to me? *grin*


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## Norm (Nov 3, 2004)

that one cell is prob. dead by now. compare it to another pack and see how it runs. if it runs like a trinity sport pack...its junked.


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## RCMits (Jan 1, 1970)

whats funny is my 2400's nicads that i still have run strong (only for practice) but still.. =)


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## BradJ (Mar 30, 2004)

I had a old pack of 3300s go off like 17 shotguns, knocked my table down, blew the lights off the ceiling. Blew the north wall clear out of the building we were in and while we were outside filling out the police reports the building burned down killing 8 people including 3 orphans. Well, maybe not exactly like that.


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## burbs (Apr 21, 2002)

my guess is the cell was venting,, i have heard this before.. sometimes one of the cells will charge faster then the others.. it gets over heated inside, and it will try to release the exes gasses.. I would say as long as you didnt see anything leaking you should be fine.. when it really vents it makes a hissing sound.. I saw a buddy have one that did go off like a shotgun.. it blew the whole inside of the cell out like a bullet.. It scared the crap out of us, and no one got hit with debris... But it sure was cool to see after.. I wonder if his pack with one totally hollowed out cell will still keep up .. ah ha


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