Anatomy of a burning LiPo

The anatomy of a burning LiPo

Recently I had occasion to see a lithium polymer (LiPo) battery pack swell up quite a bit and get a bit “squishy”, and knew that was its death knell.  So I cut off the battery leads, one wire at a time to avoid shorting through the jaws of the wire cutter, and stripped off the decorative shrink wrap and the inner white plastic protective film.  That left me with only the thin foil like covering on the cells.  I soaked the pack in a bucket of tap water for two days, and then remembered I should have used salt water

When I removed the cells from the bath I saw the water was a yucky brown color so I figured they were done for.  I then proceeded to poke holes in the thin foil covering of each cell (there were four) using a long handled garden rake.  This resulted in a burst of unhealthy looking white smoke shooting out each hole I made.

 About the time the smoking stopped a funny thing happened---jets of fire erupted from the holes and burned pretty vigorously for about sixty seconds.  Fortunately I was outdoors and the cells were on a stone gravel surface.  All in all it was an interesting bit of fireworks.

So the moral of this story is twofold:  1) if your LiPo swells up or looks misshapen, dispose of it promptly, and 2) charge these cells outdoors and definitely out of your airplane.

Call me if you have any questions.

Dawson Gillaspy

945-0329