Ah, I see. Certainly no rattle there on my sample, and I did do several rounds of testing using the charging port.no the round power port for the power plug. I guess this power plug has little contacts in it and you can hear them moving a litte on my SRA40. But the pwoer port works well, so it must be normal.
I explain my testing methodology in more detail on my Methods page on flashlightreviews.ca. Simply put, you will need some sort of integrating chamber to collect all the light, a data-logging light meter (with sensor appropriately shielded from direct light), and a calibration standard to produce meaningful comparative results. You will also need to have a way to generate the graphs from the raw data (i.e., familiarity with data graphing software)Great review,this JetBeam flashlight looks really good ,It seems that Selfbuilt have done a lot of review here,how do you test the runtime,I am curious about it,want to test my torch in this way.:twothumbs