KL4 with 1 CR123

The KL4 seems to run surprisingly well and much longer than I would have expected on just one CR123 battery. But, I'm at a loss to explain why. Explanations?

It is underdriven so it runs cooler and doesn't drain the battery as fast. It is definitely not as bright as 2x123.

I no longer have an ARC LSH, how does it compare? I suspect it is at least close to the same output as an ARC LSH when it is run on a single 123.

The KL1 is supposed to run for 90 minutes on one 123, and 4 hrs on 2 x 123.
If you take a current measurement, you'll find that to be completely coherent with the stated runtimes.

I found out a different result, and this is true for ALL multiple cells regulated lights, that if the batteries are not well "paired" in capacity and internal resistance, they will last much shorter than what is supposed, especially for pulsed - EDC use.

I switched from a E2e+KL1 to an L1 for one of my EDC, since I use "cheap" 123s.
The SF L1, for the same brightness, draws 900 mA in high mode from a 123 - The Arc LSH-P, with a much better throw and tint, draws 500 mA.
I found that I am using the SF L1 mostly in low mode - where it draws only 15 - 20 mA, so a 123 cell now lasts me forever...

Of course, the picture will change with the new LS4...

Anthony