Thanks for stopping by.
If you went through the details of the article, it is not really relevant to the amount of Voltage, it drills down to the actual amps/electrical circuit, combined with the resistance of the recipient's body.
In such situations, 12V batteries can cause some risk (12V being a car battery), and even one delicate experiment with a 9V battery proved fatal as explained in the post.
Feel free to check out the references if in need for further explanations
Thanks again!Hey there @Hornblende