I don't agree that it's wasting
lots of power. The resistor is not mounted on a heatsink and I can still hold it. Probably burning off a few watts only. I prefer the standardisation and the fact I can fit four of these tiny supplies in a nice black ABS box. I've ordered two boxes as well to fiddle with. I'll take some power readings to see how many watts it is using and work out effciency in/out.
EDIT
Just checked them Mains consumption is 50W according to my meter for a 220ma 167V dc output into Battery.
So 50W input power translates into 36.74W output power. 73.5% effciency.
I've just ordered another 8 of these psu's to make up a total of three grid chargers, one for me and two for customers
