TK75 Runtime Tests

Here’s are a few runtime tests so that you can see what you might expect running the TK75 in the real world. All tests were done using Panasonic 3400 cells with Orbtronic¬†protection.

Run times estimated by Fenix are using their own 2600 mah cells. The advertised runtimes are as follows:

Low: 200h @ 18 lumens
Medium: 12h @ 400 lumens
High: 4h @ 1100 lumens
Turbo: 1h 15 min lumens

TK75 Runtime on High

I set the TK75 on high and let it run until it stepped down to medium. The light ran for a total of 4 hours and 46 Minutes. Fenix rates the light for 4 hours on high, so I was impressed with the bonus 46 minutes of run time from 3400mAH cells charged up to 4.18v.

TK75 Runtime Test – High – Near Freezing

At 40 degrees the TK75 ran for only 4 hours and 25 minutes. You might have expected it to perform more poorly, but at high the flashlight puts out heat to make it slightly warm; maybe 80-90 degrees Fahrenheit. I think this heat dispersed through the body of the flashlight allowed the batteries to stay at a decent temperature. It probably would have performed much worse at a more extreme temperature such as 0.


TK75 Med Run Time Test

Fenix TK75 flashlight using 3400 mAh Batteries. Total runtime was 14 hrs and 43 Minutes.

2 hours and 43 minutes longer than the advertised run time. I was happy with this!

With the Run time Kit

Fenix provides a run time kit that extends the flashlight and allows you to double the run time. They actually suggest that you can more than double the run time with a run time kit because their is less pressure on the cells with more cells in parallel.

In the case of the Panasonic cells there wasn’t much of a pickup in runtime. Probably because the cells do a good job with the high current flow.

I ran the High test with a run-time kit and got 9hrs 43minutes. So if you have Panasonic batteries you might as well only get the runtime kit if you will be using turbo quite a bit. Otherwise it’s easier to just carry extra cells.

This was the end of my TK75 runtime testing because I didn’t have the patience to test the 200h runtime on low and wasn’t brave enough to test running continuously on turbo for 1hr and 15 minutes. The TK75 steps down automatically every 20 minutes or so so it would have been a pain to sit there and restart it every 20 minutes!


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