New Fenix XM-L flashlights - TK21, TK41 and TK70

[CyberCT]

Something interesting I came accross, the TK70 on high mode (930 lumens) puts out more light than the TK41 on turbo (800 lumens), and uses less current (TK70: 1,930 mah; TK41: 2,234 mah) while doing so. Look at the graphs posted by HKJ here:

http://www.candlepowerforums.com/vb...-TK70-with-measurements-and-outdoor-beamshots
http://www.candlepowerforums.com/vb...-TK41-with-measurements-and-outdoor-beamshots

I guess that because even though the XML can be driven twice as hard as the XPG, the higher it is being driven past the 50% mark, the less efficient it becomes. So the TK70 driving 3 XMLs at 643.3 mah (1,930 mah from the driver / 3 LEDs) is more efficient than the TK41 driving 1 XML at 2,234 mah, while providing more light. And the TK70 can be run on 3 batteries and the head does not get hot at all running on high mode while the head of the TK41 does get hot running on turbo. And the TK70 will last twice as long as the TK41 on high mode too.

 

[HKJ]

Something interesting I came accross, the TK70 on high mode (930 lumens) puts out more light than the TK41 on turbo (800 lumens), and uses less current (TK70: 1,930 mah; TK41: 2,234 mah) while doing so.

There is two factors:
1) Efficiency of led is higher at low current, you can find a curve in the data sheet.
2) The TK70 is never and probably uses a higher bin led.

There is also a third factor, but I do not believe it affects my measurements:
Temperature: a led has less output at higher temperature.

 

[CyberCT]

HKJ, using 3 vs 4 batteries in the TK70 should not affect the current driven to the LED by the driver, correct? The only thing affected is the load on the batteries.

Both the TK70 and TK41 both use the XML-T6 binned LEDs though. Unless you mean the T6 LEDs picked by Fenix for the TK70 are at the top range of the T6 class, right below the U2 class.

 

[HKJ]

HKJ, using 3 vs 4 batteries in the TK70 should not affect the current driven to the LED by the driver, correct? The only thing affected is the load on the batteries.

Yes, as long as the battery voltage is high enough to sustain the selected brightness.

 

[CyberCT]

Yes, as long as the battery voltage is high enough to sustain the selected brightness.

The TK60 which is essentially the TK41 but with either 3 or 4 D batteries, will run on turbo mode for almost 3 hours on 3 D batteries. And that drives the LED harder than the TK70 on high, so it shouldn't be a problem. Seeing how the beam pattern of the TK70 is like the TK35's beam (floodier than TK41) on steroids, the TK70 is going to make an awesome snorkeling light. Can't wait until the weather gets warmer to take it into the river. The high mode alone will slightly beat the TK40/35 with double the runtime. Turbo mode of the TK70 will be too bright for swimming close to crevaces and such underwater so high mode will do well there.

 

[kj2]

A week ago, I bought the AOD-L diffuser for my TK41. Very happy with it, but wanted to know if Fenix also would come with a orange one. got this a answer;
" Sorry to tell you that we don't have orange diffuser now. But we have red diffuser.... " - So no orange, but a red one is coming??

 

[csmyth3025]

Hi all,

Last October I sought out your advice concerning the suitability of the Fenix TK-41 for use in my job as a (night shift) sewage plant operator. First, thanks for your excellent responses. I'm happy to report that this flashlight seems to have been designed for exactly my type of usage. Most of the time I use the low setting for reading guages, checking for seal water leaks, etc (fairly close-up work in dimly lit areas). What surprised me was the number of times I've used the high and turbo settings to inspect equipment and process conditions at a distance - something I was never able to do before. Fenix has saved me from needlessly climbing a lot of steps and ladders.

I use my flashlight frequently for short periods (30 seconds to a minute, usually) throughout my shift. Occasionally I may use it for 2-3 minutes (sometimes in high or tubo). I've been doing this for the last five months and I'm still using the same AA batteries that came in the box!

I'm a very satisfied Fenix customer.

Chris

 

[Samy]

Hi all,

Last October I sought out your advice concerning the suitability of the Fenix TK-41 for use in my job as a (night shift) sewage plant operator. First, thanks for your excellent responses. I'm happy to report that this flashlight seems to have been designed for exactly my type of usage. Most of the time I use the low setting for reading guages, checking for seal water leaks, etc (fairly close-up work in dimly lit areas). What surprised me was the number of times I've used the high and turbo settings to inspect equipment and process conditions at a distance - something I was never able to do before. Fenix has saved me from needlessly climbing a lot of steps and ladders.

I use my flashlight frequently for short periods (30 seconds to a minute, usually) throughout my shift. Occasionally I may use it for 2-3 minutes (sometimes in high or tubo). I've been doing this for the last five months and I'm still using the same AA batteries that came in the box!

I'm a very satisfied Fenix customer.

Chris

Great to hear! I use my TK 41 every night too, it's a really excellent light!

Cheers

 

[kj2]

Question; Does somebody know, if the XTAR protected 18650 (3100mAh) will fit in the TK21?

 

[kj2]

Fenix on their Facebook; "Fenix is designing one accessory making TK70 compatible with Extended Runtime Kit. Stay tuned!" - Wonder what it is