When connecting a car battery charger
The correct method is NOT to switch it on at the mains, grasp both metal clips firmly, and connect them both at once.


Edit: Something very similar is true of turning the power off before changing a lightbulb in an inaccessible socket.
( MatJ LOOK, Fri 24 Sep 2010, 12:49, 7 replies)

But surely it's only 12 volts?
(jono_h, Fri 24 Sep 2010, 14:48, closed)

perhaps
but quite a bit of current
( The Incredible Sulk Finally remembered his password on, Fri 24 Sep 2010, 16:42, closed)

Yep
The current theoretically needed to kill a human is only in the ~5mA reigon, and a car battery charger puts out waaaay more than that. Fortunately, the "clench hands and jerk" reaction meant that I released the clips again and pulled them free.
( MatJ LOOK, Sat 25 Sep 2010, 0:36, closed)

If the 5mA is true,
At 12v your body would need to have a resistance of 2400 ohms or less.

Now the car battery torture scenes are ruined for me.
(Frample Tromwibbler climbs an obstacle like old people fuck, Sun 26 Sep 2010, 14:57, closed)

Apparently...
You need a current of something like 70mA - 700mA to trigger ventricular fibrillation. Anything over 1A will start causing burns and cellular damage. This is for externally applied electrical currents. On the other hand, it only needs 10µA applied directly to the heart to start it a-fluttering.

All info is cribbed directly from Wikipedia and Sir Itchalot makes no claim as to the accuracy or otherwise of said information. I thank you, ladies and gentlemen.
(Sir Itchalot has a very self-referential signature, Wed 29 Sep 2010, 17:04, closed)

. .
they use 12V car batteries to torture people !
(Bitter and Twisted, Fri 24 Sep 2010, 19:16, closed)

Changing a light shade.
So, i've got the lamp shade on and i'm screwing on the retaining ring. As it's a tight fit and the bulb was hot, i took it out. was only a quick job so didn't even turn the light of - just used a cloth to unscrew the bulb. As there's no bulb in, i have my thumb up the bottom just rotating my wrist getting the ring on. Slowly, as my wrist tightens the ring, it's edging toward the terminals inside. I wasn't awae of this until the shock hit me and leapt down my arm feeling like being beaten by 50 people very qiuckly. Itthrew me off the chair I was standing on. Cunfused for a second, I went to the switch, turned it off and got back to work. The mental shock hit me about 10 minutes later!
(sunray18, Sat 25 Sep 2010, 14:33, closed)