Hi i wanted to make a little hand heater for walking in the cold. The plan is to make a little clay square and put some wire in it, fire the clay and that should give me a good temperature conductor.
I know i should use nichrome for this but ive noticed that copper wire actually heats up very fast too using a 18650 battery( i used 20 gauge bare copper wire and a 3000mah 3.7v fully charged 18650, as soon as i touched the terminals, 5 inches of copper wire got burning hot).
My question is why not use copper wire? It gets hot and hardly has any resistance, but i would put a resistor in there too just to not overheat the battery, i would also use the hand heater in bursts( not continuously), so is copper wire a bad idea for a hand heater? Why?