ArmyTek        
Results 1 to 22 of 22

Thread: 3 cells in an L4

  1. #1
    Enlightened Wiz's Avatar
    Join Date
    Dec 2003
    Location
    England, UK.
    Posts
    70

    Default 3 cells in an L4

    I have seen a body tube extender on eBay for the "e" series Surefire, which allows you to run 3 CR123s in a L4. I know that this should work fine with an KL1 as they have a voltage input range of 3 - 10 volts and so should just result in longer run times, but has anyone tried three cells in a L4? Would I get extended run times or am I likely to fry it? [img]/ubbthreads/images/graemlins/eek.gif[/img]

    Any help greatly appreciated...

  2. #2
    Flashaholic* chamenos's Avatar
    Join Date
    Aug 2002
    Location
    Singapore
    Posts
    2,143

    Default Re: 3 cells in an L4

    if i'm not wrong you'll smoke the KL4 if you run it on 9 volts [img]/ubbthreads/images/graemlins/tongue.gif[/img]

  3. #3
    Enlightened Wiz's Avatar
    Join Date
    Dec 2003
    Location
    England, UK.
    Posts
    70

    Default Re: 3 cells in an L4

    Shame [img]/ubbthreads/images/graemlins/frown.gif[/img]

  4. #4
    *Flashaholic* IsaacHayes's Avatar
    Join Date
    Jan 2003
    Location
    Missouri
    Posts
    5,876

    Default Re: 3 cells in an L4

    I belive it is only a Boost circuit. So it will overdrive it... Might not smoke the LED (circuit, not sure) but you won't be able to run it very long without it getting too hot for the LED.

    The KL1 is both boost/buck. (boost for 1 123) (buck for 2-3 123's).

  5. #5
    *Retired* The_LED_Museum's Avatar
    Join Date
    Aug 2000
    Location
    Federal Way WA. USA
    Posts
    19,418

    Default Re: 3 cells in an L4

    I think you'll let out all the magic smoke in your KL4 bezel if you try to run it on three cells. [img]/ubbthreads/images/graemlins/frown.gif[/img] [img]/ubbthreads/images/graemlins/jpshakehead.gif[/img] [img]/ubbthreads/images/graemlins/frown.gif[/img]
    My opinion is much the same as IsaacHayes's in this regard.

    However, I've never tried to run the KL4 with three cells, so I haven't smoked one and have no specific evidence to prove the KL4 would indeed get smoked on three cells. I *think* it would, but I have no proof to that effect.

  6. #6
    Flashaholic*
    Join Date
    Apr 2003
    Location
    Central FL, USA
    Posts
    931

    Default Re: 3 cells in an L4

    I've read that people have tried it and got a very bright light, but as others [including SF] have already said it probably won't last very long. Not recommended.

  7. #7
    Flashaholic* Stanley's Avatar
    Join Date
    Jul 2003
    Location
    Canberra, Australia
    Posts
    1,532

    Default Re: 3 cells in an L4

    It'll run the KL4, and like what others have said, it is not recommended. IIRC, while it may not necessary smoke your KL4, but it would probably shorten the lifespan of the LED. So, use at your own risk, I suppose...

  8. #8
    Flashaholic*
    Join Date
    Feb 2001
    Location
    Perth, Western Australia
    Posts
    1,208

    Default Re: 3 cells in an L4

    IIRC, the circuit description for the KL4 suggested that it was boost only and that any battery voltage above the Vf of the LED would send it in to direct drive. In direct drive with 9V, the 5W LED should survive with sufficient heatsinking, but the KL4 head does not provide sufficient heat sinking, so you'll most likely fry the LED in a few minutes.

  9. #9
    Flashaholic
    Join Date
    Dec 2003
    Location
    Raleigh, NC formerly Kent, England
    Posts
    204

    Default Re: 3 cells in an L4

    These are the same answers that I got when I remember asking the same. It was the first thing that went through my mind when I heard about the L4 - big disappointment.

    All these bright LEDs are great, but I guess I am still only partially excited when I get 65 lumens for about an hour then a bit of trailing brightness. We've been there for a long time with incandescents!!

    For those folks that aren't doing special ops and SWAT entries where 20 mins per HOLA is fine...being able to get good long runtimes as well as good performance has to be a goal here. Show me 150-300 lumens with 2-3 hours run-time in a package the size of an M6 and I'm more interested...I guess that the now infamous U2 will sort of get close because the variable output will enable much longer run-times when you aren't needing to blind folks...

    The irony of all this is that my KL4 is on an E1e body for even less run-time, but then it qualifies by being "super tiny".

  10. #10
    Flashaholic
    Join Date
    Dec 2003
    Location
    Raleigh, NC formerly Kent, England
    Posts
    204

    Default Re: 3 cells in an L4

    OK, so I had to try it...

    KL4+vitalgear 3x123 just for a few seconds...

    In a word.....Amazing.

    Totally different flashlight.

    With the broad pattern at a much, much brighter level, it felt like running my M6 indoors and I don't say that lightly. I've no idea what it was putting out but it left my P91 (200) looking decidedly dim.

    Maybe, if you can risk the possible loss one day, it's worth it for short periods of bright light...

    Wow, I wish I hadn't tried that...


    Simon

  11. #11
    Flashaholic*
    Join Date
    Oct 2003
    Location
    Denmark
    Posts
    846

    Default Re: 3 cells in an L4

    How about the dc-dc converter - Is it still regulating with normal 6V pack or is it fried to permanent wide open?

    Jan

  12. #12
    Flashaholic*
    Join Date
    Jul 2003
    Location
    Louisiana
    Posts
    3,635

    Default Re: 3 cells in an L4

    The L4 has a boost circuit in it, so running it with 3 cells is pretty much running it in DD. This can't be good for the circuit. For things to work correctly, Vf of the lux much exceed Vin.

    Depending on the Vf of your lux, you could toast it pretty quickly. As for the board, I think you're risking damage to it.

  13. #13
    Flashaholic*
    Join Date
    Sep 2002
    Location
    Mesa, AZ
    Posts
    3,454

    Default Re: 3 cells in an L4

    Biggest risk to the board is the shottky diode. Though they're pretty robust, if it pops, you take out the controller with it. Personally, I'd be more worried about the circuit than the Lux since I believe the circuit is the weak link. On the other hand if the Lux pops, it too could potentially take the circuit with it. Not worth the few seconds of s**ts and giggles for the potential of hours of crying afterwards [img]/ubbthreads/images/graemlins/grin.gif[/img]

  14. #14
    Enlightened Wiz's Avatar
    Join Date
    Dec 2003
    Location
    England, UK.
    Posts
    70

    Default Re: 3 cells in an L4

    TnC run 5 watt leds in direct drive from 3 123 cells ( http://tnccustomproducts.com/Merchan...tegory_Code=5F )so the Lux should be ok, or am I missing something...?

  15. #15
    Flashaholic*
    Join Date
    Sep 2002
    Location
    Mesa, AZ
    Posts
    3,454

    Default Re: 3 cells in an L4

    Yes, the Lux may be OK. There's other things in the circuit that may or may not be able to take the excess current. It will probably be OK, but...

  16. #16
    Flashaholic* Klaus's Avatar
    Join Date
    Sep 2001
    Location
    Germany
    Posts
    1,998

    Default Re: 3 cells in an L4

    With three fresh Lithiums cells and/or 2 fresh and fully charged LiIons youŽll fry the circuit - been there, done that. The KL4 will still run nicely in DD mode then with the above stated cells but no longer will do any boosting anymore, so no more 2x123 or single LiIons then.

    And its not the Diode as far as I can tell - Chris, I happily sent you the fried circuit for a post-mortem check on whatever blew if you are interested to find out.

    Klaus

  17. #17
    Flashaholic*
    Join Date
    Sep 2002
    Location
    Mesa, AZ
    Posts
    3,454

    Default Re: 3 cells in an L4

    Klaus,

    Yes, I'd like to find out what blew. So how long did it run on 3x123's? Was it for a few seconds/minutes or longer?

    CM

  18. #18
    Flashaholic* Klaus's Avatar
    Join Date
    Sep 2001
    Location
    Germany
    Posts
    1,998

    Default Re: 3 cells in an L4

    IŽll email you and ship it Thuesday

    Klaus

  19. #19
    Moderator
    Join Date
    Feb 2003
    Location
    CA
    Posts
    11,877

    Default Re: 3 cells in an L4

    Klaus, did PK send you a copy of his response to me re running three 123's in the KL4. This was when KL4 first came out and I was wondering about three 123's? He said he was sending copy to a fellow CPF'er in Germany.

    Bill

  20. #20
    Flashaholic* Klaus's Avatar
    Join Date
    Sep 2001
    Location
    Germany
    Posts
    1,998

    Default Re: 3 cells in an L4

    Yup that was me - I did feedback to him what happened to me later then - I donŽt think SF did extended testing of non supported configurations though, quite understandably. PK did help me out very friendly on the issue as did one unnamed fellow flashaholic as well so my KL4 is back in working order for a while already.

    Klaus

  21. #21
    Moderator
    Join Date
    Feb 2003
    Location
    CA
    Posts
    11,877

    Default Re: 3 cells in an L4

    Yeah, he was not sure if harmful or not at that time. I lost track of development, and never knew if the buck-boost, like the KL1, was used in any other SF circuits. He did say, at the time, that the KL5 would be a different circuit, or was it KL6. Not sure.

    B

  22. #22
    Flashaholic* Klaus's Avatar
    Join Date
    Sep 2001
    Location
    Germany
    Posts
    1,998

    Default Re: 3 cells in an L4

    I think there wasnŽt too much testing done and PK certainly wasnŽt missleading us - but again - a "proof" circuit is going out to CM as I type and probably heŽll find what let out the magic smoke - chances are this part could get a beefier replacement and while the LED will still get too hot when hotrodding the circuit with 3x123 / 2 LIons it at least wonŽt get fried anymore then - thanks to CM for looking into this for us [img]/ubbthreads/images/graemlins/thumbsup.gif[/img]

    Klaus

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •