I think the gadget in the amazon link above is only for drawing or
propelling water without heating up the water, right? You'll still need
sort of propane or a heating element that connects to a heat source
(car cigarette burner or a flame or an oven), right?
The link below indicates it's possible to heat up water with just batteries:
anyone know where I can buy a ready-made water heater (for shower)
that operates purely on batteries?