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  1. #1
    Senior Member patrick07's Avatar
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    Can A 3W LED = 145 Lumens?

    I was at my local Menard's picking up conduit hangers for a DIY flashlight-headlight setup and walked through the flashlight section. I was ready to get a Rayovac 1W Outdoorsman Extreme until I could get something better but my wife saw this 3W / 145 lumen light for $12.99. I figured I needed another light for the house even if the packaging turned out to be a lie so I got that one instead.

    It did turn out to be a fairly bright, bluish light and had a nice combo of flood and spot. It worked well enough on an unlit street so that I could make out the both edges of the road but I think the moon played a role in that as well. I couldn't outrun it at 18 mph so it should work okay.

    Anyway, are 145 lumens even possible on 2 AA with a 3W LED? It seems really far fetched.

    I'm going to post a picture of the package in a minute....

    Last edited by patrick07; 11-06-08 at 07:45 PM.
    ...

  2. #2
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    Yes, the latest LEDs put out over 200 lumens when running at 3 watts. However, it appears that many manufacturers say "3W LED" meaning the LED they used is capable of operating up to 3W, but its doubtful they are actually running it that high. At 3 watts two AA should give about 1.5 hours runtime depending on the efficiency of the driving circuitry. That might give you an idea of what wattage its really running at.

  3. #3
    Senior Member patrick07's Avatar
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    Quote Originally Posted by ellerbro View Post
    Yes, the latest LEDs put out over 200 lumens when running at 3 watts. However, it appears that many manufacturers say "3W LED" meaning the LED they used is capable of operating up to 3W, but its doubtful they are actually running it that high. At 3 watts two AA should give about 1.5 hours runtime depending on the efficiency of the driving circuitry. That might give you an idea of what wattage its really running at.
    Ah, thank you! That's what I was looking for. I'm still new to lighting and didn't do very well with circuits in school. This fog came up every time I looked at circuit diagrams in physics.

    Thanks again for the info. Every bit will help me make informed decisions about run time, beam shape, and intensity on my winter light setup.

    Sincerely,
    Patrick

    EDIT: Is there anyway of finding out the manufacturer of the LED?
    ...

  4. #4
    aka Phil Jungels Wanderer's Avatar
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    Look on the emitter. If it is a CREE, it will say so, usually on the board it is attached to.

    How about posting a pic of the light itself?

  5. #5
    Senior Member patrick07's Avatar
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    The entire light is just under 6 inches long. In the second picture, the emitter board is press-fit into the lens cap so taking it out without damage seems impossible. There were some markings on the underside but I have no idea what those are. The barrel of the light is just textured aluminum with an anti-roll bezel. There are two o-rings on the inside of the lens cap and the battery cap, presumably to make it water resistant.
    ...

  6. #6
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    Quote Originally Posted by patrick07 View Post
    EDIT: Is there anyway of finding out the manufacturer of the LED?
    Take a close-up picture of the LED looking directly into the front of the flashlight. Someone will be able to tell the make by looking at it.

  7. #7
    Safety Zealot wyeast's Avatar
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    Realistically, you're probably looking at anywhere from 60-100 lumens from a 2AA light. Those already exist (Inova Bolt 2AA, Coleman MAX 2AA). You could go higher, tho' more often those are driven by CR123's or some other battery that can handle the amps better and/or they are using more efficient emitters that are usually too expensive to show up in generic store-branded lights.

    At $12.99 (regular price?) I would be quite surprised if it was anything better than a LuxIII, K2, or an XR-C type of Cree, which probably puts you closer to 45-80 lumens.

  8. #8
    Senior Member GTALuigi's Avatar
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    yes i do have a cheappy $12 3W, and it does pretty damn good at aprox 180 lumens
    but now that i switched to the P7, it's... still holding up quite nicely

    the P7 at high, and medium beats it hands down
    but the P7 on low, is dimmer than the 3W at High
    they both about the same when both are set to Low
    Mu SL Gone in 10 sec!
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