Shorted Ni-MH PP3, should I be worried?


Newly Enlightened
May 12, 2017
I was about to use one of my 7dayshop 250mAh Ni-MH PP3 batteries when it fell and shorted its contacts across a bolt that was lying on my workbench. I didn't notice for a few seconds, but when I did I quickly stood the battery up and felt it cautiously with the back of my hand. It was not hot, but it smelled a bit weird. I binned it (recycled), but I am worrying whether I have caused any injury to myself by taking a whiff of the battery after it shorted. It didn't give off any visible vapors (smoke), it just smelled like adhesive/old medicine. Should I be worrying?


Newly Enlightened
Dec 28, 2012
New York

I don't think you should be worried. First, NiMH cells don't vent all that easily, and second, the NiMH chemistry isn't volatile the way Li-ion is and generally doesn't catch fire or explode even under abusive conditions. A brief short, even if it winds up generating enough heat to melt a bit of plastic or adhesive, is unlikely to destabilize the battery in such a way that would make it a hazard.

You may have slightly reduced the service life of the battery due to the extreme load, but I would not be worried about safety, not even a bit. In fact, I would probably just continue using the battery as normal.

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