Got the idea for these two small lights after I ran across a couple of oddly shaped lipo batteries. Unlike the typical lipos I've seen, these two are longer and thicker rather than being flat:
I had some left over copper tubing from a water line replacement and found that the battery would fit in perfectly. Made one in all copper and one with a copper body and brass caps. Next to a Quarck CR2 mini for comparison:
Made the all copper light with an older XR-E and the copper and brass light with a newer XP-G2. The XP-G2 is a bit taller to accommodate the longer reflector it needed:
I don't have a shot of the circuit but I am using the controller from a X-light Micro, driving a P channel mosfet. The XR-E is running at 380mah on a fully charged battery, the XP-G2 is running around 900mah. The batteries are rated at 220mah but 4x discharge isn't that much of a stretch for a lipo. This is what the inside looks like on each light. The blue LED is a beacon that lights up the switch cap to help locate the lights in the dark (the small silicone and Glow Inc X10 fob hanging off of the Quark is it's version of a beacon). The blue LED runs on approximately 5 micro amps on a fully charged battery so it would take years to run the battery down:
The heat sink is fairly thin but it contacts the copper tube its entire length and it seems to do a good job transferring heat to the body.The lights will definitely get toasty after running for very long on high.
Uses a really tiny power jack to recharge the batteries. I've been charging it with a computer controlled hobby charger to help get the most life out of the batteries. That white ring inside is polypropylene to assist in diffusing and distributing the beacon light:
Since everything is soldered up inside, there are no springs to contact the battery and I have been able to get away without having to machine threads to hold the switch cap on. Basically I crimped the brass switch cap very slightly in a vice to provide 4 hold down points. There is an inner seal that fits over the switch and inside the copper tube and an outer seal that acts as the switch cap that goes between the end cap and the inner tube. The split ring just provides extra metal to hold the outer cap in place. Not sure how water resistant it actually is but I have tested it down to about a foot of water and one cycle through the washer (that test was purely an accident) and it did not leak:
The high beam shot is from about 15 feet away. Couldn't get the camera to focus very well but you get the idea; tight center spot with lots of spill. The XR-E looks pretty similar although much dimmer. It's difficult to do the X-Light Micro controller justice with pictures instead of video but this is a high and low beam shot. The low was too low for the camera to get a picture of the beam at all, so just a shot of the business end: