Author Options:

Is it possible to feel a zap from a watch battery and LED? Answered

Here's the setup: one LED with its leads tied by conductive threads to magnets which stick to a watch battery, in contact with skin for multiple hours. 

I had somebody say that this somehow was zapping them (enough to leave a rash).  Is this possible?  I've handled lit LEDs with watch batteries a lot (even underwater) and never felt a thing!  No spark, no zap, no shock, nothing.  So have I just been lucky?  Can this setup actually zap you enough to feel it, or even irritate your skin?  Or was the zapping perhaps an allergic reaction to the nickel magnets which was mistaken for being sparked?


The forums are retiring in 2021 and are now closed for new topics and comments.

8 years ago

If someone said they got a rash, I'd bet they have a nickel allergy. AFAIK, conductive thread is made with a few materials, and nickel is a common one which a lot of people are very sensitive to; and the result is called "contact dermatitis". (I get this with any exposure to nickel).


Reply 8 years ago


You probably might feel a little tickle from a 3V battery on some kind of mucosa - like your mouth or, ... errr, ... well, some other areas (works with a 4.5V or 9V battery on your tongue, never tested anything anywhere else.. :-)

Otherwise , you will need some kind of voltage multiplying circuit - some oscillator and capacitors and/or inductors. Just a battery, an LED and some wires - no. The LED would be fried before you notice something.

The allergic reaction on the other hand - if you are sensible, nickel can give you a nasty rash, especially if it is in contact with the skin for longer periods.

You will notice a zap immediately, while an allergic reaction will take a while to build up.