I am trying to develop a product that would use a portable heating element. For example: If I wanted to use a coil burner, is there a way I could make it cordless using lets say a rechargeable battery? It does not necessarily have to be a coil burner. It just has to been something that can heat up to 400-600 degrees. Weight is also an issue. I can't have it portable using something the size or weight of a car battery. Thanks for any help.