Battery, jump leads = Welder

[Dorset Lad]

I certainly wouldn't want to be doing this infront of the batteries as the guy in the vid was doing. If the rod was to "stick" to the work as happens in stick welding, you have effectively short circuited the battery. Lead acid batteries have a nasty habbit of exploding when you short circuit them or at the very least getting extreamly hot. You could melt the insulation off of the leads too.
In my oppinion this is something for dire emergencies only.