vr, no you are correct. It's just that the circuitry is built into these lights. I know mine has a little PCB in it.

I didn't get to report yesterday, but here is what is going on. I have ridden a couple of days with the Phillips Energy Saver MR-16, the yellowish one in the picture above. Although I prefer the whiter light of the Solux, the Phillips does, as advertised, seem to put out the light equivalent to a 35W lamp but draws only 20W. As long as I am using a 5 AH battery it will probably be my primary lamp. The 20W Phillips provided good light for 2 hours, 20 minutes compared to 1:20 for the 35W Solux. For the other trivia geeks out there, I tested my system with each Lamp. According to my meter, the 20W Phillips draws 1.6 amps and the 35W Solux 2.9 amps, confirming the results of the formula.

The latest on switches. I stopped by the marine store, too, and found nothing that looked useful. Everything is too big and open on the back. In looking at a handlebar mount remote switch from an old Vistalite set it looks like all they did was embed a switch in rubber then snap a cover over it with a rubber membrane over the switch itself. I plan to try something similar, basically take a small switch of appropriate power rating, slather it with liquid tape, mount it, then slip a piece of innertube over it. I have fashioned a bracket to mount the switch and the light. It's not as elegant as I hope to eventually make, but it will serve as a test bed for now.

All of my splices are just twisted and wrapped with tape for now. As I decide something is working I will solder and liquid tape, perhaps with shrink tube over that for cosmetics. I am keeping all connections tucked out of harm's (and water's) way, all in a Tyvek envelope inside my bar bag with the little battery.

You know if you just need to run a 20W or less light for an hour or less, there are some little 2.3 AH SLAs that are small and light. Check out some of the little batteries here:
http://www.sciplus.com/category.cfm?...3&category=134
and the page after it.
I'm tempted to buy some of the small ones and parallel them. There's even a 2000mah (2 AH) nimh 7.2 pack that one could series for 14.4 and try some of that overvoltaging stuff. The mind boggles at the possibilities...