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3 x 1 Watt 12V MR16 CREE XLamp XR-E WHITE 240 Lumen LED on ebay $22+tax+$5shipping
vs.
Xenon MR16 Watts: 10W Volts: 12V Amps: 0.830 P/N: 881210 from www.sailboatstuff.com $4.95+tax+shipping.

I have been using the 10W halogen/xenon bulb (30 degree) for a year and a half mostly for pre dawn commuting. No problems, but I was looking for a little more light and longer battery life both for commuting, and for long distance rides 200 miles+, where extended night time riding is common. The LED bulb states 3.6 Watts consumption, although I have not verified this. I am running this off a batteryspace NiMH 12V 4500mAh. So at 3.6W, I'll be looking at 15 hours max runtime. I am curious what happens as the voltage drops on an LED bulb? How do I know the battery is low?

The CREE 3x1 watt LED MR16 bulb at 15 degree was impressive, although I had to take a hammer to my optronics housing.. few strikes with a steel 12mm socket as a spacer to knock the ceramic MR16 socket holder back a millimeter or 2. YMMV. The LED MR16 bulb also has a protective glass cover held in place by 3 screws, which is needed with the Optronics lenseless holder. Only drawback I see is the "fins" on the bulb allow water to enter the housing. This could be sealed with some silicon, but I plan to leave it as is for now for air cooling. The housing is always pointing downward, so water should not collect.

Notice in the photos that the LED bulb has better vision outside the 15 degree range, even compared to the 30 degree 10W halogen. You can see more detail to the left of the board on the left side. In addition to that super bright focused spot.

CREE 3x1 watt LED 15 degree


10W halogen 30 degree


CREE 3x1 watt LED out of box


LED bulb in Optronics housing


SharpT