Streamlight Protac HPL USB sustained output??

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Dec 5, 2008
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The 1,000 lumen is not a regulated output according to their own fact sheet.
You'll have to dig deep into the fact sheet to find the graph but it starts at 1,000 lm, then plummets to 500 lm or so in 7 1/2 minutes. Whether this is the function of freshly off the charger 4.2v cell or it's thermal, I don't know. They don't tell you anything about the recovery curve (i.e. if you run it for 5 minutes, rest for a minute, then restart, where does it start?)

Given this characteristics, I would've assumed much similar runtime between high and medium if the high quickly plummets to 500 lm and medium is only 400 lm. They don't show you the curve for medium or low modes.

This light can use the proprietary 18650 based cell that can be charged in the light, any protected 18650 or 2xCR123A.
Is the curve any different for 6v operation (CR123A)?

HPL USB.jpg
 
The 1,000 lumen is not a regulated output according to their own fact sheet.
You'll have to dig deep into the fact sheet to find the graph but it starts at 1,000 lm, then plummets to 500 lm or so in 7 1/2 minutes. Whether this is the function of freshly off the charger 4.2v cell or it's thermal, I don't know. They don't tell you anything about the recovery curve (i.e. if you run it for 5 minutes, rest for a minute, then restart, where does it start?)

Given this characteristics, I would've assumed much similar runtime between high and medium if the high quickly plummets to 500 lm and medium is only 400 lm. They don't show you the curve for medium or low modes.

This light can use the proprietary 18650 based cell that can be charged in the light, any protected 18650 or 2xCR123A.
Is the curve any different for 6v operation (CR123A)?

View attachment 28288

I'm no expert, but I think I understand the run-time for the two highest outputs perhaps seeming inconsistent. Per the Fact Sheet it is rated per FL1-2019 of course, and the way I understand it is: After the initial short period at a given / stated output (minimum 30 sec.), the run-time is then rated down to 10% (which is also stated on the Fact Sheet) of that applicable initial rated output. So the maximum output of 1000 lumens is run-time rated down to 10% of that, which is 100. For the medium output which is maximum 400 lumens, after its initial qualification period at that value, its run-time is rated down to 10% of that value, which is 40 lumens. Therefore, given each of the two output levels, the run-time for 400 spends some of its time running at levels lower than levels the 1000 L test ever even gets down to, in addition to not running at the higher levels, and that also adds to its rated run-time.

The initial / rated highest value of the output being tested must maintain that value for at least 30 seconds, as that's when the run-time clock starts. Following that, that ramp-down looks to me like it occurs over a period of maybe 8-10 minutes(?), which is likely comparable with competitive lights.

Personally I consider the output to be very well regulated during most of the period of its run-time output / graph - meaning regulated output with respect to / despite decreasing power supply voltage from the cell(s). That's my understanding of the definition of 'regulated'.

I too haven't noticed any published output data using CR123As, but it's nice it's designed to accomodate them.
 
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I'm running some tests right now. I'm unable to produce the drastic drop indicated in the graph. The graph is terrible. No in-between scale. No indication of it being logarithmic or linear even.
 
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