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Thread: Any ideas why L1 advertised for 5hrs but gets 1.5

  1. #1

    Default Any ideas why L1 advertised for 5hrs but gets 1.5

    I was sort of sad about the 5 hour misprint???
    The graph shows 1.5 approx hours in the manual that comes with it.

    I would have returned mine but I am so pleased with it I am keeping it.

    I have had 3 LS from another mfg fail within a week...so I am thrilled to get anything that works. I was about ready to give up on LS's. The color is nice and white with a very slight tinge of purple when using a new battery.

    FOR ME...I am finding that it is exactly what I want. I use the low-beam function most of time. Now that I have played with it for a week I am sold on it. I really like not burning through the batteries as low works for me most of the time.


    I put a 3/4 dead 123 in it and noticed that the L1 will blink on and off at a regular slow rate.....but the light will keep quite bright as it ramps down. Has anyone else noticed this?

    You need to have an almost dead battery and let it sit for awhile for the L1 to start to blink. I assume it is the voltage regulation circuit doing its thing.


  2. #2
    Flashaholic*
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    Default Re: Any ideas why L1 advertised for 5hrs but gets 1.5

    There is no way that a 1W Luxeon can run for 5 hours at full brightness on a single 123. A perfect circuit (driving at 400mA) would allow runtimes in the neighbourhood of 2.5 hours (probably even less). I think Surefire has tried to be very candid about their runtimes (as evidenced by the graph you mentioned). My understanding is that the L1 will provide 5 hours of useable light (and 1.5 hrs at full brightness). I admit I don't like the term 'useable light' but the 5 hour figure is quite useful to know.

    Cheers.

  3. #3

    Default Re: Any ideas why L1 advertised for 5hrs but gets 1.5

    Thanks Montezuma.

    I am finding that I am getting MORE than the 1.5 hours.
    I use the bright intermittently however.
    I was wondering about the following....

    1) Get 2 L1's.
    2) Get 2 brand new 123's.
    3) On the first L1, turn it on 5 min at a time, 3 times
    a day...for 6 days.
    4) On the second L1, turn it on for 30 min at a time one
    time a day...for 3 days
    5) Stop on both when you reach total time of 1.5 hours

    Question...which L1 would be brighter after the test?

  4. #4
    Flashaholic Mister T's Avatar
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    Default Re: Any ideas why L1 advertised for 5hrs but gets 1.5

    The first one will be brighter [img]/ubbthreads/images/graemlins/eek.gif[/img] (thats what i think)
    I wonder if they use a step-up controller and what its efficiency may be. The KL1 uses a buck-boost which has a lower efficiency and it runs for 1.5 hours too. Confusing. [img]/ubbthreads/images/graemlins/confused.gif[/img]

  5. #5

    Default Re: Any ideas why L1 advertised for 5hrs but gets 1.5

    I got this information in a private email...
    This is sort of what I have been getting....


    [ QUOTE ]

    The L1 kinda has a mind of it's own..... what you are describing is quite common.... there are several "about to go dead"
    behaviors for the L1. SureFire has no explanation, yet



    [/ QUOTE ]

  6. #6
    Flashaholic*
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    Default Re: Any ideas why L1 advertised for 5hrs but gets 1.5

    Interesting experiment. I would not be suprised if the second L1 appears brighter. Here is my twisted (and unconfirmed) reasoning. On the average the second L1 runs hotter. This means that its average Vf is slightly lower. Since we are using a current regulator the overall drain on the battery is slightly lower. The battery on the second L1 would therefore be fresher. Then again how the heck should I know? [img]/ubbthreads/images/graemlins/grin.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

    Cheers.

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