Car spotlight, 12v cable, small bit of wire from bulb to switch, makeshift handle, on/off switch and a motorbike battery is all you need
Little bit of wire from the halogen bulb to 1 side of the switch, then big wire from bottom of switch to battery.
Other wire core going direct to the back of the lamp to make the current.
Attach handle to spotlight and link to battery
Switch it on and away you go
I remember making them over 15 years ago now, god I feel old