Our electric kettle for boiling water for tea or coffee has what looks like a minimum mark at 0.8 litres (though on closer inspection it says “mini” rather than “min”!). I try to save energy by boiling no more than the amount actually needed for my drink, which is often as little as ca. 0.3 litres, but always enough to cover the base, and have seen no ill-effects so far.
For what it is worth, the kettle in question is a Moulinex Subito made in China rated 2-2.4 kW where the element is concealed under an almost flat stainless steel bottom, but I suspect that pretty much any similar kettle would behave the same way.
Is there any danger in this? If it does depend on the model, what features matter?