[acranox]

Another factor I haven't seen mentioned in the responses yet is safety to human bodies. You (or your kid) can stick a wet finger in a 12V DC charger socket in your car and not get an electric shock, including any of the exposed contacts under the hood, including the battery terminals. But once you're up to 40-60V, the risk of electric shock to humans is actually something that needs to be factored in.

[R0b0t1]

You'll get a shock if wet slightly below 9V. It just stays on your skin. Voltage penetrates dry skin at around 50V, and this is the legal definition of high voltage.

[HeyLaughingBoy]

Something I learned around 12 years old, licking the terminals of a 9V battery :-)

[oehtXRwMkIs]

What amperage are we talking about here? Discussions of electrical safety solely in terms of voltage is nonsense.

[marsokod]

Amperage is set by the resistance of the human body. That's in the order of 2kOhm, so at 50V, you get a current of 25mA. That's in the zone where it becomes quite intense for you.

At 12V, we are just talking about 6mA, where you can feel the electricity but it should not be hurting too much.

[oehtXRwMkIs]

Thanks, that makes sense.

[YZF]

40V is still fine IIRC. I think 48V is the threshold.