How Many Lumens is this Putting Out?

I bought a Q5 drop-in from Lighthound for an old Surefire 6P. How many
Lumens is this producing? Thanks for the info

need more details... specifically which drop in?

Surprisingly led binning isn't the only thing that determines brightness. I found that out when my Q5 606A outshined my Q5 drop in. How much power is driven to the led is what matters. In this case the 606A drives about 800 mA to the led at 3.5 volts which translates to 2.8 watts. The Q5 drop-in drives only 500 mA at 3.2 volts to the led, only 1.6 watts. This means less light, not a ton less since at lower power the leds are more efficient but it is noticeable.

I have a directly driven P4 led drop in, and on a fresh 18650 it draws 1.6 amps at 3.9 volts at the emitter(It's probably slightly more if you acount for the .1 ohm resistance of the multimeter) but that's 6.24 watts of power with no power losses due to a convertor. This thing is bright but can get dangerously hot if tailstanding, surprisingly you own hand can wick away enough heat to keep the light cool because I've specially heatsinked it. Extrapolating from the cree led chart which maxes out at 1 amp, this led should emit about 300 lumens, which means about 270 lumens out the front of my light, it's about right according to my camera's light meter.

But all we're saying is your results may vary, but you can get a good idea of how bright your light is by measuring how much current it pulls.

As others have said, depends on many more factors than just "Q5"

Tell us what batteries you are using to drive it, what state of charge they are in, and what the current across the tailcap is, then we can give a rough approximation of lumens

Eric

If it's this drop-in, then 750 mA which means around 190 lumen at the LED, or 130-150 out the front.