What is causing this module to do this?

As you can see from this video, from the second this laser is turned on, the current starts to drop almost instantly.
This test was done with fresh batteries that where putting out a total of 12 volts.
The driver is a Rckstr
The diode is a LOC 20X or 22X...not sure.
The heat sink being used was this.


Here is the video.


Any ideas as to what is causing this? The batteries are good...I am 100% sure of that.
Also, as far as I can tell, heat doesn't seem to be the issue

Thanks for your help.
Iskor12

Are those 10440 batteries that I see in that picture? And is it 3 X 10440?

If so, you want to start with checking the battery holder to see if the little plastic taps are preventing the positive end of the batteries on any of them from making good contact. See this picture:


Then try swapping out all three batteries with three new (charged ones) Sometimes a battery will show full voltage, but fails when a load is put on it.

So try those things first. If it's is not that, then there is a problem with the driver...
Jay

.....and if it still does it use the volt meter across the batteries to see if the voltage stays up when you switch the laser on.

Regards rog8811

Thanks for your help guys....I turns out that it was the batteries.....even though they where brand new....DX must be selling some bad ones right now.