New to the forum. Thought I'd share... Having built a couple of sets of HID automotive headlamps, I had some leftover parts kicking around and an old 10 million CP spot/flood light. The 12v SLA battery was junk and I hadn't used the light in years. Time for an upgrade...! I picked up a new battery, LED volt meter and some spare HID parts around the basement. The original bulb was a 55/85w H4 automotive type bulb. I replaced it with a 35w 5000k tilting HID burner and a slim ballast that tucked nicely under the reflector dish. I carved a window in the top of the housing to put my LED volt meter to watch the charge and discharge states. One of the existing power switches now drives the ballast, and the other the tilting magnet to give me the spot/flood light output. The internet says HID bulbs are 3.5x brighter than halogen, so I've created what? A 35,000,000 candlepower monster? The original run time was just about an hour with the halogen. I timed the conversion at just about 2 hours runtime until the ballast shuts down at around 8.5v... Enjoy!