Salvagable or too dangerous - Shorted Lipo Pack with Small Vent Hole

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bakaneko   100 W

100 W
Posts: 203
Joined: Oct 25 2018 6:25pm

Salvagable or too dangerous - Shorted Lipo Pack with Small Vent Hole

Post by bakaneko » Aug 15 2020 6:11pm

Sigh, so I frocked up. The crap electrical tape I used to insulate between terminals of my 4s pack somehow came loose and shorted with another cell in the pack. So, it actually was slightly smoking before I was able to pry apart the short. But, the result is one of the packs has a small hole where it vented and electrolyte is oozing from it (if you press the cell).

I assume this is now too dangerous to use though it still holds voltage and I is rideable though I notice a bigger voltage sag now than before. Think this is repairable or no? I assume I need to seal the small hole (black dot in picture) but that needs to not leak when I press the pack... Problem is that it is right at the edge of the cell pouch so hard to get tape on it.

Lesson learned is to not rely on electrical tape and add another stronger tape over that as well as some more insulation between tabs. I will replace both the one with the whole and the one below it too.
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Tommm   100 kW

100 kW
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Joined: Apr 03 2018 2:32am

Re: Salvagable or too dangerous - Shorted Lipo Pack with Small Vent Hole

Post by Tommm » Aug 16 2020 9:46am

Lipo is dangerous from the day you buy it. Legacy tech for diy.

bakaneko   100 W

100 W
Posts: 203
Joined: Oct 25 2018 6:25pm

Re: Salvagable or too dangerous - Shorted Lipo Pack with Small Vent Hole

Post by bakaneko » Aug 16 2020 5:42pm

Its a LiFePo pack from LG Chem, which goes into many EVs. People make DIY powerwalls with this that are literally fastened to a flammable wall. A pure LiPo pack is dangerous I agree but this isnt that. I sealed it back up with hot glue and then taped it but the packaging of the cell pouch is compromised and the internal resistance is extremely high. I will just replace the cell pouch or make the bike into a 14s from 16s so 60V to 52V. I learned my lesson with insulating the tabs properly...

https://www.youtube.com/watch?v=Qzt9RZ0FQyM

Note in this video, a puncture test, over voltage, and short circuit did not result in explosion or fire. Just venting of fumes which is what I encountered in my short scenario which was briefer than in these test.

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