I have a question about my Electrical Engineering Stack Exchange post: Probability of explosion of a 100 µF, 25V capacitor when powered at 5V

I'm not sure as to why it was closed (it's also debated in the comments). But still, I have modified based on what to the person who closed it wrote. Is there anything more I should do?

I just need some information on the probability of an exploding capacitor. And if anybody has information on the associated decibel amount 5 cm from the source I'd be glad to be helped.

There's not much information available on the internet ...


1 Answer 1


I don't think there is a chance to reopen this question because there are only opinion based information around.

I assume, nobody has ever measured the sound level of the little "plopp", that such a capacitor produces. And this happens only under heavy AC load current, wrong polarity, overvoltage or too high temperatures. The word "explosion" is not really appropriate here. Big motor or X-capacitor failures are more spectacular.

If there is no fuse in the supply path, an excessive current can cause fire, but this does not make a loud sound either.

In your application heavy AC load current cannot be fully excluded. There is no datasheet, no circuit diagram and no specification of the used motor.

I once received a batch (750) of capacitors (D=10 mm, H=12.5mm) with internal manufacturer faults. They all popped open after half a year of continous use. I could not prove it, but I assume they had a wrong polarity marking. This was not even as loud as normal speech.

In a safety context sometimes the polarity of capacitors is verified before the placement. I made a tester for the big capacitors used in airbags, that provide the ignition energy in a crash when the battery fails.

So I understand why you are worried about this, but as long as you buy electronics from such sources you are not on the safe side anyway.

  • \$\begingroup\$ Thanks! Is there a way for me to understand how powerful that "plop" would be? \$\endgroup\$
    – talhos137
    Jan 8 at 23:51
  • 1
    \$\begingroup\$ I would describe it this way: If I hold a thumb horizontally tight bewteen my lips, create a little negative pressure and pull it out quickly, I produce a similar sound level but the frequency band is lower than that of the capacitor sound :) \$\endgroup\$
    – Jens
    Jan 9 at 0:04
  • \$\begingroup\$ Haha :) Seems pretty harmless when described like this, no? Do you think I should avoid using this board at all or maybe do you have another replacement idea? \$\endgroup\$
    – talhos137
    Jan 9 at 0:10
  • \$\begingroup\$ I'm sure there's a function between capacitance and pyrotechnic side-effects in case of errors. The more energy it holds, the bigger the plop. \$\endgroup\$
    – Lundin
    Jan 11 at 11:56
  • \$\begingroup\$ That's probable, but very hard to find. And we can't really benefit from the community of this website since the question has been closed. If you have any information on that matter I'd be very happy to know :) \$\endgroup\$
    – talhos137
    Jan 13 at 1:47

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