LiPo battery pack destroyed?

[akio123008]

I've just shorted out a bunch of LiPo batteries and I've got no clue what's wrong with them now.

 

I had four 3.5 Ah 25C 11.1v 3s batteries connected in parallel in order to power a car starter which I was using as a traction motor for my bicycle. (I know that's far from optimal, but that's what I was using those batteries for) The system worked brilliantly, until a mechanical issue caused a short. The short only lasted for a very short amount of time, as I was able to rip out the battery pack quite quickly.

 

There are no signs of damaged LiPo cells (no bulging for example). However, there's no voltage across the terminals of any of my four batteries (0.0000 volts). Also, when I plug in a LiPo charge indicator through the balance leads, the device tells me it's a 2 cell battery, with each cell being about 4 volts. I suspect there may be some internal wiring that's gone up in smoke, meaning that the third cell in each pack is disconnected now. What's so strange though, is how every one of the four batteries has exactly the same issue. What are you guys' thoughts on this?

[WereCatf]

3 minutes ago, akio123008 said:

I suspect there may be some internal wiring that's gone up in smoke, meaning that the third cell in each pack is disconnected now. What's so strange though, is how every one of the four batteries has exactly the same issue. What are you guys' thoughts on this?

Could be a wire that melted, could be a fuse -- if the fuse is at the end of the 3rd cell, you'd see exactly the kind of results you're seeing. The only way of knowing for sure is opening the packs up and checking.

[KarathKasun]

The batteries are likely internally open circuited by a protection mechanism or by failure inside the cells.  Dead shorts destroy LiPo's VERY quickly.

[akio123008]

14 minutes ago, WereCatf said:

Could be a wire that melted, could be a fuse -- if the fuse is at the end of the 3rd cell, you'd see exactly the kind of results you're seeing. The only way of knowing for sure is opening the packs up and checking.

That's what I suspected too, I guess I'll open them up then. 

[akio123008]

33 minutes ago, WereCatf said:

Could be a wire that melted, could be a fuse -- if the fuse is at the end of the 3rd cell, you'd see exactly the kind of results you're seeing. The only way of knowing for sure is opening the packs up and checking.

Yep. turned out that the third cell wasn't hooked up anymore. I've opened up one of the batteries and found that all cells are fine using a multimeter. Thanks for the help!

[WereCatf]

1 minute ago, akio123008 said:

Thanks for the help!

You're welcome!

[julie tylor]

you can check more info about Lipo Battery Maintenance from https://blog.ampow.com/lipo-battery-maintenance/