The Truth About Run Time

[NH Shooter]

How long a light will run is an important consideration regardless of the intended use. This is especially true for lights that are left on and used for considerable periods of time.

ANSI FL1 is the standard used by flashlight manufacturers to specify the run time of their lights. It defines the test for run time as follows;

The duraton of time from the initial light output value – defined as 30 seconds after the point the device is first turned on – using fresh batteries, until the light output reaches 10% of the initial value.

But how meaningful are these numbers?

I conducted a series of run time tests using the Malkoff E2XTD direct-drive head used on Fat Boy, and the E2HT head used on Dagger, powered by an Orbtronic IMR 18350 1200mAh flat top cell.

Of course both the Fat Boy and Dagger are intended for personal security where their high-candela output is critical. The photo below illustrates the difference between 100% output of the E2HT on a fresh cell vs. allowing the cell to get depleted to 10% of the original output level;



It's obvious to me that at 10% of the initial output, the light isn't going to be very useful for a self-defense application. It should also be noted that at 10% output, the cell is almost entirely depleted.

Here are two graphs based on my run time test data that we can get a better feel for the usable run time of these lights. Using the ANSI standard and freshly-charged Orbtronic 18350 cells, these are the results I obtained;





The E2XTD is a direct drive head (3.5 - 4.2 volts), meaning there is no voltage regulation. This maximizes output on a fully-charged cell, but output continuously declines as the cell voltage drops. For the Fat Boy model, the ANSI FL1 run time is 19 minutes, but I would suggest 12 minutes as the usable run time. Keeping a fully-charged cell in it at all times is certainly going to maximize its effectiveness.

The E2HT has a voltage range of 3.5 to 6.0 volts, so it can be used with a pair of CR123 batteries in an E2 body. As you can see in the graphs, the voltage regulation provides a substantial plateau in its output between 6 and 16 minutes of run time. For the Dagger model the ANSI FL1 run time is 27 minutes, but I would suggest 18 minutes as the usable run time. Recharging the cell before 16 minutes of run time will not have much impact on its performance.

***For most lights, I would reduce the manufacturer's ANSI FL1 run time by 35% to arrive at a more meaningful value.***

Carrying spare cells to maximize the performance and run time of these lights is an excellent idea. The "external fuel tank" below is part of the 18350 Fuel Pack offered with the purchase of these lights;




I hope you find this information useful, and as always thanks for taking a look!

[BillSWPA]

When the ANSI standard came out, it was heavily and correctly criticized on Candlepowerforums for favoring poorly designed lights. A well-regulated light with a flat output curve that produces the stated lumens for the stated runtime will look worse than a direct drive light producing 10% of the stated output at the end of the stated runtime.

The Malkoff heads actually output the stated lumens for the stated runtime. The purchaser has a very accurate description of what is being purchased.

I suspect that many do not understand that the cheap light described as having 300 lumens and a runtime of 1 hour is not producing 300 lumens for 1 hour, is likely producing far fewer lumens after 30 minutes, and is only producing 30 lumens at 1 hour. If we have a reason to need 300 lumens, getting only 30 is not good. It is borderline deceptive.