xm-l at 3A and 4A under real condition

LED Flashlights – General Info
1

I just made a quick test with an xm-l T5 at 3A and 4A, the tests lasted for 7 minutes in both cases, initial body temperatures were the same in any case

I was curious how change (decrease) the overall brightness with difference current.

The led is in a TR-500 TR-1200 dropin, so the heat transfer isn't the best, but acceptable.

Just for comparition, I made the same test with a Jetbeam BC 40.

here is the result (in relative brightness):

here are the accelerated videos:

at 3A

at 4A

edit:

What happens, when I remove the battery holder tube and loose the head a little.

Ignore the initial brightness, maybe I didn't put the light to exactly the same position.

More important that how decreases the brightness with worse heat dissipation.

videos:

3A

4A

2

According to your tests the XM-L T5 is brighter than T6 and brighter than any XM-L U2.

Selfbuilt estimates arount 760-800 lumens for some 3.3A driven XM-L U2 flashlights.

3

okay, it is only relative brightness

4

interesting data, thanks

5

After 7 minutes stabilize to 11% brightness increase and the current draw is with 33.3% more.

The higher amps should be theoretically more useful in dedicated throwers since they concentrate the light more. On a floodier light a 100 lumen gain will be harder to detect by the eye.

6

Most interesting!

7

People should buy more of the DRY. hehe.... Sealed

What....7 minutes? I already chicken out at the 2nd or 3rd minute, gets too hot over here with the local high temperatures. But that's ok....

But wow, you dared to use P60s for this. Salute!

8

Okay, I see the failure in my first post. It is a TR-1200 TR-500 drop-in, much bigger. ;)

like this:

9

Oh...ok, and the body tube is definitely more massive (relative to a single XM-L) to soak up the heat as well as has at least 3X more surface area. Coz actually i really wanted to ask why the drop isn't as much, my P60s dive like there is no tomorrow due to heat.

And btw, would you kindly share your XR-E 0.5A - 1.9A video as well? I really like how the output scales from 1A to 1.5A. I haven't done any experimental recordings but from "feeling and playing around" I knew that generally it is ok to drive to about 1.4-1.5A even for a P60 size light. I have a Dereelight DBS v3 aspheric that is driven to about 1.5A. Thanks bro, all your effort is much appreciated!