Introduction: Test the Strength of a 9V Battery With Your Tongue

Picture of Test the Strength of a 9V Battery With Your Tongue

Wondering if your battery is running out of juice?  Stick it to your tongue briefly to know for sure.

First inspect the battery for any noticeable signs of degradation, rust, battery acid, etc.  If the battery seems reasonably clean, stick it to your tongue.  You will feel a slight jolt and metallic taste.  You'll probably need to calibrate your tongue by testing a fresh battery and a dead battery to get an idea of what to expect.

Luckily my friend SHIFT! was around today to demonstrate.  Notice his pained facial expression in the first image, this is definitely a new battery.  In the second image he seems unfazed, this battery should disposed of.


nflpanthersfan (author)2017-03-18

Those faces he made are not what he would actually make if he was not doing it for demonstration perposes, i tried it and its only a small momentary "burning" feeling on my tongue

KirstyH12 (author)2017-02-08

Yum yum.

chaparro78 (author)2015-03-13

I did it with a crank generator 100 volts and 10 people holding hands... cool

tbarot (author)2014-03-30

I had a battery lying around and thought of trying it and just loved it. it's a new experience for me and I tried it 3-4 times

KGuy (author)2013-07-01 father told me to do this when I was young. I remember looking at him thinking it was a joke.....but his face was very serious. I still love this way to test it :P

KemikalzAreFun (author)2013-05-10

I may be a little weird, but when I was younger I used to do this for fun... When you're homeschooled you don't have to many friends to hang with... This was fun :P

iceng (author)2012-12-06

So as a teenager I wanted to make an electrical Popsicle to alleviate sugar from kids teeth.

In the experimental process my tongue learned  to tell positive from negative and
voltage within 2 volts up to a painful 12VDC.  Also DC and AC.

BTW 52 ibles in just a little less then a year ... WOW


junaidi81 (author)2012-09-27

yeah. me too. i was a kid once. cool.

ejp1087 (author)2012-08-10

I do this all the time to check 9V batteries. I don't see why some people think this is dangerous. I even had one guy warn me that I'm going to kill my self after he saw me do it once :) 9V batteries can't put out all that much current, and the current that does come out just goes from one spot on your tongue to another spot less than an inch away. Sure it might sting a little (it more just tastes funny) but it's nowhere near your heart or brain so you'll be just fine.

youn_link (author)2012-08-02

this is dangerus and irresponsible, and belive me is crazy do this with brakets

lord_kian (author)2012-07-23

This is a good but not ac cúrate método to test a battery a battery solución is buy a cheap multimeter

Steven.Work (author)2012-07-06

Warning - there is a larger voltage battery which is the same shape and general form then the regular 9 volts. 24V - I think. This procedure above will knock you on your bottom.

caitlinsdad (author)2012-07-03

Are the results back for testing with a car battery?

mohitdaksh (author)caitlinsdad2012-07-04


I think his eyes popped out! All I need now is someone who would like to test my 9V batteries!

wfelix (author)2012-07-03

I was a kid once...

About This Instructable




Bio: I'm a grad student at the Center for Bits and Atoms at MIT Media Lab. Before that I worked at Instructables, writing code for ... More »
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