Fire at Michigan State Champs

[Kevin Sevcik]

Originally Posted by Jaci

When a high amperage electrical circuit shorts, touching the metal chassis of the robot is a good way to become less alive.

You might be badly burned if the frame is hot, but Ohm's law plus physiology says you're extremely unlikely to suffer any injury from the electricity itself. Wikipedia says the resistance of wet skin is about 1 kOhms. So a 12V battery can push, say, 12 mA through you. The chart on that page notes that 12 mA of AC would be noticeable after a few seconds, but not deadly. It's important to note that DC is much less dangerous in this regard than AC. Unless you have wires connected directly to your heart[1], it takes a lot more DC to kill you than AC. If anyone is doubtful, I can hold a demonstration at Champs where I will bravely grab both terminals of a robot battery with either hand an suffer no ill effects.

Mind you there's plenty of other dangers from the battery, but they're all the fire, explosion, direct-short causing a welding arc sort.

TL;DR: The robot battery (and your car battery[2]) aren't going to electrocute you unless you stab a positive and negative wire from them into your heart. In which case you have plenty of other problems besides.

[1]I have before. It was weird.
[2]Had a dead battery once in college and got a jump from a doctor. He gave me the same electrocution warning. And he should know, because he's a doctor. I didn't argue because I wanted to get home.