Hello, I don't know much about electronic devices, so please don't laugh at my question
Is there a battery operated kettle or cup to boil water? And if not, could something like this be created? Because I personally have never seen it anywhere. I am constantly traveling (on trains) and lugging full thermos bottles on my back is very taxing. Such a wonderful kettle or mug that would somehow boil water on its own, without a socket or electricity, e.g. with a battery or something similar, would make life much easier.
