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Old 12-06-2005, 02:47 AM   #1
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Default Battery "Shelf-Short" Question

i have a pack of sanyo 3600mah batts (side by side)..
i charged it at 3.6amps since its not very stable and cant take high amps charging ..

BUT .. here comes the problem ..
after charging the batt,i let it to cool abit and it was luke warm..
thinking tat it was cool enuf ... i chucked it into my speedmind bag which has foam cushioning ...

bout and hour later when i took it out, it was freaking hot .. like something shorted the battery.
i checked the bag for any loose metal chip of somesort but there wasnt any.
How could it self shorted by itself ?
this is juz one account.

ANother acount is after the 1st account.
Knowing tat my batts can stay in the controller bag when warm ..
i left it in my MR-4TC when LUKE warm..
its almost to room tempurature already ..

An hour later .. the same thing happened ..
it seem to have shorted out of nowhere ..
and now the battery is damaged and lost lots of capacity.

I m damn sure tat there's no possibility of any chunks of metal shorting the beatt.

How is it possible tat the battery sort of get shorted juz like tat ?
i m super confused.
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Old 12-06-2005, 07:43 AM   #2
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I cant answer why your pack is doing that. But I can say get rid of it fast. I lost All my gear last December 15th 04 due to a shorted pack. It started a fire and almost lost my garage also
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Old 12-06-2005, 08:33 AM   #3
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I remember seeing the pix of Howards incident, I still think about it everytime Im putting batteries away......
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Old 12-06-2005, 11:23 AM   #4
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interesting post... I don't have any clues but I have a question for you.

after the 1st time they self shorted did you quickly discharge them and then tray the pack?

secondly when I travel to and from my track I have like 50% or 500secs of charge time on them and then discharge them @ the track to do a full charge... personally storing fully charged packs sounds extreamly dangerious after reading this.
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Old 12-06-2005, 03:41 PM   #5
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I have seen this occasionally.. The reason if ound was the battery bars.. i had it happen to two farely new packs.. the battery bar workedits way through the shrink wrap on the cell.. it shorted out on the casing of the cell and cause it to basically blow up... i was there when it happened so no major damage was done..

check all your battery bars and make sure they are not touching the battery in any place other then the place soldered.. the heat from the iron when building the pack can cause the bar to melt through the shrink wrap when building..
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Old 12-06-2005, 04:31 PM   #6
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Quote:
Originally Posted by Deznuts05
interesting post... I don't have any clues but I have a question for you.

after the 1st time they self shorted did you quickly discharge them and then tray the pack?

secondly when I travel to and from my track I have like 50% or 500secs of charge time on them and then discharge them @ the track to do a full charge... personally storing fully charged packs sounds extreamly dangerious after reading this.
No.. i didnt tray it ..
i didnt have the appropriate equipment at tat moment.
I juz charged my pack at home and went to straight to track (bout 15 to 30mins away).

When it heated up during the 1st account, i left it to cool and connected it to my car ...
it has no power at all ..
seems discharged and the energy in the batt burned up by itself ..
like a set of batteries tat went flat after a day of playing.

later tat day ... i discharged and charged the battery ...and my charger shows that the battery peaked at 2300+ mah ...
and when i went to track .. it lost its punch and loads of playtime..

I have been tinking about this for days ..
how the hell could it happen

Last edited by lost; 12-06-2005 at 04:42 PM.
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Old 12-06-2005, 04:33 PM   #7
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Quote:
Originally Posted by burbs
I have seen this occasionally.. The reason if ound was the battery bars.. i had it happen to two farely new packs.. the battery bar workedits way through the shrink wrap on the cell.. it shorted out on the casing of the cell and cause it to basically blow up... i was there when it happened so no major damage was done..

check all your battery bars and make sure they are not touching the battery in any place other then the place soldered.. the heat from the iron when building the pack can cause the bar to melt through the shrink wrap when building..

I was sure tat my battery bars were alright..
if they werent alright ..
how my batts were to work before these accounts?

i m still confused ...

Last edited by lost; 12-06-2005 at 04:43 PM.
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Old 12-06-2005, 04:36 PM   #8
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Quote:
Originally Posted by howard hudson
I cant answer why your pack is doing that. But I can say get rid of it fast. I lost All my gear last December 15th 04 due to a shorted pack. It started a fire and almost lost my garage also

man ... sorry to hear bout tat..
it muz have been damn bad since u can even remember the day it happened.

anyway .. the Annivasary of your garaaged burn is coming..

jokin ..
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Old 12-06-2005, 05:58 PM   #9
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There could have been a small rock that got in between the cells and scratched the shrink wrap and caused them to short against each other. Plus, depending on how hot it got, it could have split the shrink wrap. I've found that you don't ever want to put a battery that's even the slightest bit warm into any confined space where air can't get to it. I had a pack vent in my battery case a few years ago and ruin about $400 in batteries because it was still warm when I put it away and packed my stuff up. That was the one and only time I ever did that.
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Old 12-07-2005, 12:26 AM   #10
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Quote:
Originally Posted by Jon Kerr
There could have been a small rock that got in between the cells and scratched the shrink wrap and caused them to short against each other. Plus, depending on how hot it got, it could have split the shrink wrap. I've found that you don't ever want to put a battery that's even the slightest bit warm into any confined space where air can't get to it. I had a pack vent in my battery case a few years ago and ruin about $400 in batteries because it was still warm when I put it away and packed my stuff up. That was the one and only time I ever did that.
i am sure tat my batt pack didnt have any small stuff or anything tat caused the short. I checked throughly thrice and the shrink wrap still looks new and unscratched.

So, u also had similar accounts of batteries heating up by itself. Wad could have caused this ?

Sadz... people out there.. never store your batts with any slightest heat after charging !!

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Old 12-07-2005, 01:05 AM   #11
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Quote:
Originally Posted by howard hudson
I cant answer why your pack is doing that. But I can say get rid of it fast. I lost All my gear last December 15th 04 due to a shorted pack. It started a fire and almost lost my garage also

I better store my batteries better. They're individually wrapped in paper tossed in a box full of rc parts, sitting in my basements. Disaster waiting to happen...
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