Surefire E1D runtime question

SO I found this online and it shows the runtime is at a steady decrease. I'm wondering is this because of thermal regulation, as in if the light were turned off and back on in a few minutes, would it be back to full brightness?

It looks like Jim Bashan's text beneath that chart indicates that it is related to battery depletion (i.e. voltage drop). Seems typical. I suspect that if it were turned off and then back on, the light would return to full output, but only for a short while until the voltage sagged again.

Definitely voltage sag.
I imagine if Jim were to use a LiFePO4 cell the runtime would be shorter, but output would be a lot flatter.

Edit:
He did use a LiFePO4. I posted without looking at the link, just remembering the E1D output curve from memory.

In actual use, it's just as described: turning it off gets me to full power again when the battery recovers, while leaving a long tail of decreasing outout till battery exhaustion.

I like this better than full output for X amount of time then rapid decline to nothing, so I use primaries exclusively in my E1D.

Here's a 16340 runtime graph i did a while back for what it is worth. When i carry my eb1 or e1d i carry a primary only for back up and just plan on having a full 30 mins of constant brightness with my 16340

Thanks for the graph Jose.
What brand 16340 did you use?

Modernflame said:

It looks like Jim Bashan's text beneath that chart indicates that it is related to battery depletion (i.e. voltage drop). Seems typical. I suspect that if it were turned off and then back on, the light would return to full output, but only for a short while until the voltage sagged again.

Click to expand...

Ahhh that makes sense. So is there no way to regulate the voltage through boost/buck drivers to keep a constant current?

BugoutBoys said:

Ahhh that makes sense. So is there no way to regulate the voltage through boost/buck drivers to keep a constant current?

Click to expand...

You mean with a primary cell?
That would probably just involve lowering max output, so current demand would be lowered as well so the primary can sustain it better.
Sort of like the older E1L that runs flat for 6 hrs.

RobertMM said:

Thanks for the graph Jose.
What brand 16340 did you use?

Click to expand...

Efest imr 700mah, not the best battery but they do ok. Still trying to figure out a good one, sucks no big name brands make them.

Jose Marin said:

Efest imr 700mah, not the best battery but they do ok. Still trying to figure out a good one, sucks no big name brands make them.

Click to expand...

I've got an answer:
Fenix 700mAh ARB L16-700 cells.

Tested by HKJ to have around 750mAh at 100mA draw, and over 700mAh at 1Amp draw.

By comparison, I think I remember the Efests have only 500+ actual mAh as tested by HKJ too at the Batteries section of CPF.

Cool i just picked up 4 of those actually but havent done any runtime tests on them yet, thanks for the tip