Go back to SuperBrightLEDs and read through their FAQs and info pages. 3watt Luxeon LEDs are not as efficient per watt as Halogens. They spell out why. Mostly when a single LED runs that hot they are less efficient. Their multiple (up to 36) LED arrays are designed to run cool, thus efficient. But if you want real power stick to halogen/incandescent bulbs in MR16 and larger sizes. I ran a 100 watt, 6 volt, PAR36 bulb light for years til I cracked it. The store had just sold 12 to Hawaiian Airlines for wing tip landing lights when I got mine. In the Denver winter I could warm my fingers in front of it. Used a 13 pound battery tho.