Watts is just volts x amps - but LED's run on amperage, not voltage. You want more light out of an LED? Run more amps thru it. You can also cook it this way! Good LED lights have an amp regulator on them (rather than just a simple resistor), really good lights also have a temp sensor which will dial back the amps when you're about to cook the LEDs due to lack of cooling. IIRC, the life of the LED also drops as the amps go up - just like the old halogen bulbs when overvolted!
+1,, good question. Edit - Just seen your response wadester. So if more light requires more amps, more amps at the same voltage (12 I'm assuming) means more watts consumed. How can 1 change and not the other 2? If 2 lights use the same LED's, have the same output in lumens and run at the same voltage how can they not consume the same amount of watts? I'm not trying to be a smartass or anything, just curious as well because from my understanding something sounds off. I'm no expert by any definition so the problem very well could be in my understanding of it.
Part of that is how you read light emission specs. Are either of the light mfg's in possession of test reports of the light emission of their device? Or are they quoting the specs of the LED mfg for light output? I haven't pulled spec sheets for those LEDs, but I bet it says "900 lumen output" on it. You want to claim something else? Pay for a lab to rate your device - with enough samples to truly have a statistical validity.
In comparing lights output in Lumens with how many watts they consume, you are comparing the efficiency of the conversion of electrical power to light. Assuming that all the measurements are accurate, if one light puts out more lumens than another for the same wattage, then it is more efficient. The wasted watts don't just disappear however, they are converted into another form of energy, most likely heat. This is why fluorescents and LEDs produce so much more light and are cooler (generally) than halogens and incandescents. Just because two lamps use the same type of LED (and not that I have done any research on this but I would guess that Cree makes many different grades of LED with different efficiencies and quality control levels) is not the whole story. The electronics package that drives the LED could be more or less efficient too. Less efficient means more heat and heat is the enemy of electronics. So maybe you should look for the lamp that uses the least watts? I doubt that the difference between the best and worst lamps amounts to more than a few watts in the driver board, but that is just opinion, based on the idea that if the board was producing huge amounts of heat in such a small space, even great heat sinking would not save it. So Lumens per watt is the best way to compare lamps? Wait, there's more mud here. Lumens are a measure of the total light output of a source - in ALL directions. Even if the manufacturers are being truthful and accurate in what they state, the key to performance is getting the photons where you want them - the design and quality of the lens is the main variable here. A better measure of light output in a given direction is Lux, which measures the amount of light falling on a surface. As light from a lamp typically disperses with distance, more so with a flood beam than a spot beam, to compare output between lamps you would have to measure lux at the same distance from the source, and probably pretty close to reduce the errors of beam patterns. So what happens to the light that doesn't go where you want it to? It disperses uselessly (or usefully, depending on what you are trying to illuminate) or it bounces around inside the lamp and creates more heat. If manufacturers are not quoting Lux, (and some do provide isolux diagrams - Lux maps, if they can be trusted or compared) and everything else is open to interpretation, what is the best way to choose lights. For my money, I guess I would keep wattage iin mind if my electrical supply was marginal...then look at beam patterns, ruggedness, customer satisfaction, return policies etc. that's where sites like advrider are a real resource.
Had a crash today. Bike hit hard and slid into fist sized rocks. Lights are still working albeit pointing in the wrong direction.
First ride home tonight in the dark. NICE!!! Question for the crowd: What tricks are out there to help keep the rotary dimmer from moving so easily? I mounted my dimmer on the left bar, near the turn signal and sometimes bump it with the tip of my glove when I activate or cancel the directional. Was thinking o ring or plastic wire wrap around the body of the first switch to rub against the side of it and provide some resistance to rotation. Thoughts? Jon Sent from my Galaxy Nexus using Tapatalk 2
Glad to hear you are happy with the light How about a pic of your installation? Oring doesn't work very well as the knob overhangs the edge of the box and the oring will roll under the knob. I'd recommend moving it to a location that is out of the way, perhaps just rotating the box in place would work?
same here.... sent two emails today that I was returning a brand new flickering light and wanted to change out the wireless dimmer for rotary. Hopefully you will let my shipping cost for the defective light cover the difference in the dimmer cost. Also you said in an email i had to wait for a repair.... really?
The xm-l line is very efficient, but there are others out there that provide more lumens per chip. The xm-l line produces one of the highest lm/w. In the line the xm-l u2 is king of lm. Pushing chips to full potential produces a ton of heat on the upper limits and doesn't give many more lm.
The mystery remains*. Why AdvMonster model 60 with 4 Cree Xm-l T6 absorbs 29 watts while BD declares 44 watts for its Squadron light with same powerleds and lumens? The Advmonster data is real, I've tested it (more or less 30 watts depending on the actual voltage), and BD doesn't have any interest on declaring an higher consumption with same lumens. Anyway as far to now I'm glad of the AdvM light which is probably the smallest 3,600 lumens led headlight, and that's very good for off road motorcycles. *And curiosities grow: the led beam, despite its power, seems to me less deep than my feeble halogen high beam. I mean the possibility to distinguish something on the horizon. Maybe the parabolic reflector, or the led light for itself, determines an high contrasted beam without transitional zones.
Finally got around to installing my model 44s. Loving them so far! Each one individually is brighter than my stock headlight and combined its even better. The beam pattern is not ideal for roads, but I haven't seem any aux lights that have headlight like beam pattern.
