How to Mod a New L5 to produce more than 120 lumens?

I'm seriously thinking of ordering the new Surefire L5. However, I would definitely like more than 120 lumens. Is this possible? If so, what is the best way to accomplish this?



Thanks!!

Have the bias upped to approximately 1 amp to the led. This would probably give you more than 120 lumens. These are real lumens we are talking about not lumens at the emiter, per specs. Losses of all kinds can bring a Seoul P4 or Cree P4 rated at 200+ lumens at 1 amp to the led, down to 120 or so lumens out the front. At this point I am not assured that Surefire is totally accurate (don't kill me) about a 120 lumens rating for the soon to arrive new L5. Maybe if it is run at 1 amp to the led, but not sure that Surefire will want to go to that high of a bias. Of course maybe Sirefire will use the Cree Q3 emiter.

Bill

Thanks for the suggestion. I was thinking of something a little simpler for my newbie brain; like a drop in for higher lumens. Please, more suggestions everyone.
Thanks!

Uh....my L5 with 2xRCR123's is OVER 120 lumens as it is. I get about 110 actual lumens on 1x17670 cell, and closer to 150 out the front when I use 2xRCR123's. If you are not getting close to 100 lumens out of your L5, I think you have a problem :huh2:

Well, I am going to be ordering the new L5 and want to be able to increase lumens to over 120. Also want good runtime. Is there anything out there that can accomplish this?

Surefire will be bringing out a new Cree-based L5 quite soon I believe.
(maybe a few weeks' time)

This may stomp over the existing one.

Just thought I'd mention this as you may feel a bit let down if your
new light becomes "obsolete" almost immediately.

Strauss, I do believe that my KL5 is doing over 100 lumens, and I am sure that you L5 with two RCR123 is at least doing 150 lumens. If you use a DMM and read the amperage at the tail cap end (tailcap removed) you will find that the KL5 is pulling more mA's, quite a few more mA's, than the L5 with two CR123's so in effect is running DD, not regulating. If your L5 is regulating with two RCR123's the mA reading will be lower with two RCR123's than two CR123's. I tried two RCR123's and the light output was amazing, about 70% more (bounce with lightmeter). The head got unusually hot in a few minutes. The L5's (KL5) that appear to be runninng in regulation with two LiIon's probably have a fairly high vf emiter. The KL5 has a boost circuit.

Bill

Gordov2 said:

I'm seriously thinking of ordering the new Surefire L5. However, I would definitely like more than 120 lumens. Is this possible? If so, what is the best way to accomplish this?

Click to expand...

I have six different lights which have either a Cree or SSC LED which all measure between 105 and 120 lumens in a Quickbeam light box, five minutes after turn-on. I have only one, a direct drive light running a SSC LED from an RCR123 battery, which is over 120 lumens -- it measures about 140. I haven't measured the current, but I'm certain it's overdriving the LED. My conclusion is that about 120 lumens is about all you'll get from a single Cree or SSC LED if you keep the current within the 1 amp spec, and have normal reflector and lens losses. You'd have to overdrive it quite badly to push the lumen output up by 20%, which is just barely enough to notice, if you can detect the difference at all. You'd also take quite a hit in run time for that very modest increase.

c_c

Gordov2 said:

Well, I am going to be ordering the new L5 and want to be able to increase lumens to over 120. Also want good runtime. Is there anything out there that can accomplish this?

Click to expand...

SureFire garantees a minimum of true 120 lumens for the new L5. We're most likely find out that these new lights will produce more than that in real life-- as usual with any SureFire product. The old L5 is rated at 100 lumens, but a lot of people have measured an actual output of around 120-130 lumens.