Originally Posted by
Wilbur Bud
I don't know about the efficiency, but its been my experience that most automotive headlights like the ones linked tend to start at about 50 watts, and it creates too much drain for the battery I'm willing to carry. Lots of light, but probably more than I need.
That would be true for real automotive headlights. But the lights linked in the OP don't qualify. According to the answers provided in the links, the lights shown have a current draw of 0.1 and 0.15 A respectively, or wattages of 1.2W and 1.8W. So not much of a battery drain at all, but also not likely to be putting out a whole lot of light. At under 2W, I'd rather be looking at something like the Planet Bike Blaze which runs on a couple NiMH AA cells.