If I am correct what happens to a nail powered by a battery which makes it electromagnetic might be part of what the Hall Effect is

If you have ever made one of these by taking the positive and negative wires together on a large like 16 penny nail and powered it by a DC battery (very low voltage like 12 volts or below) (I have done this for science class) which makes the nail electromagnetic as long as the power is flowing through that nail might be part of what they are talking about in regard to the "Hall Effect".

There are many strange things that can happen especially when you are using DC rather than AC where you have to be very careful. However, usually most regular cars at least are only 12 volt batteries so this isn't as big of a problem. But, the kind of Batteries in a Tesla if you became a part of a short likely could kill you very quickly because you couldn't get off it because of what it might do to your muscles and your heart might stop permanently or you might suffer a fatal stroke.

Remember your muscles are all electrical and when you short out your nerves through voltage often you are done for and dead or severely maimed in various ways.