Phone Battery Foil Paper Take the battery out of a cell phone. Cut or tear a long thin strip of the foil. Foil paper can be found from cigarettes and chocolate packaging and various other products. Make the ends so they can easily make contact with the phone battery. Carefully crumple the strip, so that the flame will not easily be blown out. Attach the ends of the strip to the positive and negative terminals on the battery. As the current passes through the foil paper it heats it up and ignites it. The foil paper gets hot very quickly and you can burn yourself if you are not careful. This can also be done with other batteries not just cell phone batteries.