KL4 rated life in L4

I did a search on this topic and there seems to be a lot of debates. I tried SureFire tech support: 5,000 hours is the answer. Could this be the result of underdriving the KL4 in L4?

[ QUOTE ]
Dear sir,
It has been rated for 5,000 hours.

If you have any further questions do not hesitate to write back or call us at
1-800-828-8809. We are dedicated to providing world-class customer service and
welcome future inquiries or comments.

Stuart Yager
Technical Support


[/ QUOTE ]

I wonder if surefire considers the KL4 a Lamp assy. Because they dont offically warenty their bulbs.
What I'm getting at is: after my KL4 dies, will they replace it?

7 month. Will you leave it on for that long? Will you spend over $10000? /ubbthreads/images/graemlins/wink2.gif

I was initially thinking ... only 5,000 hours ... then I slowly understood what FC. meant by $10000. 9,230 batteries ... at $1.25 each that's $11,537.50.
I think I'll loose the L4 before I burn it out.

If Surefire did warranty it for 5,000 hours I'd love to know how you'd know if you'd had it on for that long or not after owning and using it for fifteen or twenty years.

Another perspective. Take a P60 LA at a bargain price of $10 which runs say 20 hours. 5000 hours/20 hours=250 lamp changes. At $10 per lamp ===> $2500 in light bulbs. You can buy a lot of KL4's for $2500. Now the rated life doesn't say anything about diminishing light output. LED's have what's called Lumen maintenance and that's something that's rarely talked about here. How much light output will there be at 5000 hours? 70%? 50%? If your light put out 80 lumens out of the box and only had 50% of its light at 5000 hours, that's only 40 lumens. Just a few more things to think about.

It is all moot, especially to the flashaholic. By the time the 5,000 hours is up you will have bought several new generations of LED flashlight's. The L5 is just around the corner now.

By the time the 5,000 hours is up the L4 will be considered an old technology, power sucking, heat generating, dim light.

My L4 strangely started to develop donut hole /ubbthreads/images/graemlins/frown.gif At atart, when I just receive it, it is pure white, without any visible green tint. Now, after 5 times battery change, I can see the donut hole (green darker tint) rather clearly. I find it rather strange...

Bernhard,

That is strange...

Al

Bernhard - mine has always been that way: look carefully:



If you look directly at the center it appears rather even. If you look at the 6" ring, you'll notice that the center is dimmer. Lux readings conform this - 580 in the ceater, 600 about 4" from center at one meter.

Perhaps yours was always like this and you've just noticed it?

What I'm saying is,,suppose I buy an L4 and a month or 6 months down the road, it dies. Now anybody with a calculator can set and figure out how many batteries the average L4 will go through and what it will cost, this issue has been beat to death, this is for an L4 that actually runs it's entire lifespan.
What about the L4s that werent quite up to spec and give out early.If surefire considers the KL4 a lamp,(And officially they dont cover lamps even though they do give out freebee replacements often) Your stuck with an 90 dollar paper weight. Or better yet If you bought the entire L4, A hundred and thirty dollar fishing sinker.

Bernhard,

mine did the same after a night of heavy use - still waiting for replacement though - SF claims they haven´t any at hand /ubbthreads/images/graemlins/frown.gif

And regarding the calculation of LED life and cost - using an L4 with rechargeables does change that picture IMO.

Klaus

I just got an L4 from TAD today. Quick service BTW.

Must repeat to self over and over: the KL1 is still useful, the KL1 is still useful.

Whew! That was rough.

Actually the L4 is now the light by the front door and will probably be my EDC although the KL1 is by no means dead.

It provides a terrific amount of light for times where you don't need a lot of illumination that might destroy your night vision e.g., camping. Plus the KL1 provides longer life for an equal number of batteries.

Still the L4 is the bomb and the KL5 & 6 should be too. I am very impressed and I humbly submit that I am reaffirming my role as a minion of pk.

At my current level of use, my L4 had better outlive me. If I changed batteries once a week, that would be roughly a century of use... and I don't change them nearly that often.

David <><

Quickbeam: My L4 donut hole, now, was worse than yours /ubbthreads/images/graemlins/frown.gif
Klaus: Wow, I thougt it was just me. I'm pretty sure that at first, my L4 was pure white with no donut hole whatsoever.
I even try to compare it to my bluish KL1, I thought maybe if my eyes white balance has been adjusted to blueish beam of KL1, I can pick up the slightest green tint on my new L4, and still cannot pic up even slight green tint on it.

Beretta may be able to give his opinion, as he try and compare it to two of his other L4, and my unit has brighter and whiter center hotspot, according to him.

Maybe I will consider to ask for replacement as well...

Bernard-

I just got a KL4 head from another CPF member, mine is the same as yours a slightly darker hole in the middle. I don't know how many battery changes this head has seen.

GregR