It is interesting to read all the comments on AA bike lights. I found that the Cateye 5 LED light was a little dim. I had expected it to be really good from all the info I had heard on it last year. So looking for a powerful LED flashlight I came across several AA conversion modules. I have included a description of my method and the Luxeon units that I used. I also have on my web page comparison photos of different lights that I use. While the pages are more for my cheap homemade 20 watt bikelight, look toward the bottom for the info on the AA units. See my web page: http://www.krabach.info/bike_light/bike_light.htm