SF L4: how long have you run continuously?

I have the 2-stage McGizmo cap thingie. Running a Pila 168S.

On high, which of course is how the L4 is intended to be run, it does get pretty hot.

How long have you run yours continuously? What happens to all this heat?

Cognitive,
While I don't have the L4, but the closest I have is my KL1 running on my E2e. I run it on R123s (talk about guilt free), and when fully charged, it does get a bit hot when running continuously for even a short while (which is supposed to be a good sign, as it shows that the heat is being transferred onto the surface). I would say that you won't have to worry about the heat, as the surface of the bezel is supposed to disperse the heat. My KL1 (old version) has 'fins' around the head, and this helps disperse the heat even more. Also, if you're holding the light in your hand, your hand acts partly as a conductor to help with the heat as well... Hope that helps with your 2nd question...

cognitivefun,

I've dug up one of my old posts that might be of interest to you. The 50 hours is now up to about 100 hours with the original output still intact. I have switched to an L5 for night walk duty, so I wont be continuing the test.

Jan

Jan, did you run the L4 for 50/55 minutes contant on, without any break?

Does someone know what is surefire's advise in that? is it really safe to run constant on for 50 minutes?

SF has told me that it's "ok". I have run back to back runs with the light just sitting on a tabletop. It gets scorching. So far, so good. I'd say I am at 50-75 battery changes. The light runs hotter on a pila cell than primary ones.

rastaman,

Yes. I'm running my L4 (and also my L5)(Not at the same time mind you /ubbthreads/images/graemlins/grin.gif) for 50 minutes constant on until the Pila cell is used up. Then I switch it off for a minute to change the cell, and on we go again. The L4 doesn't really get very hot because I'm walking with it, so I suppose it's cooled by a constant flow of air. it never gets uncomfortably hot.

Jan

this is such great information, thank you very much

ok, that sounds good. thanks for all the answers.

I ran mine for 2h 45m doing a runtime plot.

I've had mine on for a maximum of 3 minutes at once. i really need to order some CR123s from the battery station!! /ubbthreads/images/graemlins/grin.gif

2h 45m Roy? Hmm... tot the L4 drops out of regulation at about 1 to 1.5 hours? Sounds like its time to reconsider the L4 now... /ubbthreads/images/graemlins/broke.gif

I said that I ran it for 2h 45m......I did'nt say it was in regulation that long! /ubbthreads/images/graemlins/naughty.gif

I have ran batts dead in mine.
and yes, it will get HOT!!!

Damn near feels like its gonna burn you.
Alittle hot for my taste, but only cuz I fear for the LED.

Should be fine though, they are ment to do that. Though, I would think it will wear on the LED over time, and yes, it will have a shorter life than if it wasnt getting so hot. But, I wouldnt worry about it.

[ QUOTE ]
jtice said:
I have ran batts dead in mine.
and yes, it will get HOT!!!

Damn near feels like its gonna burn you.
Alittle hot for my taste, but only cuz I fear for the LED.


[/ QUOTE ]


I run mine quite a bit on Pilas so it runs hotter than on primaries. At times the L4 is asked to pump out the photons through a few battery changes a night. To protect the LED and control the heat I employ liquid cooling. Heat is the enemy! Your hand wraped around the head of the lght and a healthy heart pumping the coolant will keep the LED happy. I've lost a L4 due to heat issues. Heat is the enemy!

I run a Pila 168s in mine,
NOOO i would never recommend placing it on a table etc and let it run.
Your right, your hand can draw ALOT of heat out of it.

Lost one huh? think it was due to heat? did you leave it sit?