I have noticed an increase this kind of device recently. I seem to remember from when I played with this that its main issue was loss. IE there is no way to closely couple the windings enough to transfer enough power to make it worthwhile. so has there been some revolution here, or is it just some kind of clever marketing of power wasting rubbish? I mean, induction hobs could be repurposed as battery chargers using a plastic plate with a winding inside?
I was thinking about eye great leccy in bathrooms debate. One other odd thing is that Kitchens have power sockets and water and nobody seems to worry about that, and yes people do get killed due to this aspect due to accidents like power cables dropping into sinks or dodgy cowboy practices in fitted kitchens. Brian