this post was submitted on 31 Jan 2024
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Considering that a 12V battery has an internal resistance of 20 milliohms, the potential current through this thing would be approximately 600A.
It might be too hot to handle (pun intended)
You can also get that from just the label. The CCA rating (cold cranking amps) is the max current that specific battery can supply in short bursts. 600 CCA is pretty typical, but I've seen up to 900 in the batteries I ship.
Is it really 600 amps? That seems rather high. I do know that the one time I shocked myself on a car battery, it rocked my world much more than getting shocked by a 110v outlet.
V = IR Assuming 12.6V 12.6 = I* 0.02 I = 630
So yeah, it could hit 600A, if only until it got hot enough to melt something or change the chemistry
Well that explains why it hurt so much.
They say amps are what kills you. It's not true. You need a trifecta of current, Voltage and resistance. And usually it has to go through your heart, causing an arrithmea. Though I have seen people get their hands blown off on a 400V system.
Your body has a very high resistance. If your hands are sweaty and you place them directly on a couple of 12V terminals you might get a tingle (I've done this several times on accident on 24V bateries).
That's why I always laugh at the movie trope of people being tortured with battery cables.
But there's more. Electricity takes the path of least resistance so in this case it would probably bypass your body altogether.
But as soon as you connect this you'll get a giant spark (basically how welders work). If that doesn't perturb you and you somehow successfully connected this, it would get REALLY hot and burn you before it shocked you.
It has been 20+ years since it happened, but I'm pretty sure I was standing in a little puddle, or my hands were wet (can't remember which), and my wrench just happened to bump the positive terminal and it was like "POW! Right in the brain!". Thankfully I didn't latch on or anything. It was instantaneous, and over in half a second, but it rocked my world for that half second or whatever it was.
My guess is you were burned more than shocked.
Wait you can get shocked on a car battery??? I thought 12V was too low for you to feel.