Originally Posted by
hamster
USB is de facto standard for midrange lights. Cheap lights use batteries because they are weak and they can last a while on standard batteries without burning a hole in your pocket (one AA battery is 3 Wh, 2 AA batteries will power a 60 lumen light for 6 hours.) High end lights require custom chargers. In the middle, it's all USB.
I've got to agree with mrbubbles on USB. USB is relatively new and isn't any kind of standard, de facto or otherwise, especially when you consider what the market has to offer. Midrange lights aren't in the $60 to $100 range anymore. That's high end compared to what's available for $20. Even weak "cheap" lights that run on AA are expensive (and worthless, IMO) compared what's available on the market. The Cree's that are currently available put out 10 times the light that the "cheap" lights put out for about half the cost. There's a little more bother in charging and maintaining them but that's minimal.
Originally Posted by
hamster
150 lumens per watt is a spherical cow, you don't see those outside labs or theoretical papers. 60 lumens per watt is what you see in the real world.
Well, heck, my old overvolted 12V MR16 put out 60 lumens per watt. I may have to dust them off again
