specialk
Newly Enlightened
Does running the LoD Q4 on high for 30 minutes or more hard on the led or cause premature dimming of the led?
Fenix L0D Q4 running on high
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Marduke
Flashaholic
no. If you're worried, keep you hand on the light as a heat sink.
LEDninja
Flashlight Enthusiast
As long as you use regular AAAs no problem.
If you use 3.6V 10440 lithium ions, it is a different matter.
If you use 3.6V 10440 lithium ions, it is a different matter.
Luminescent
Enlightened
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- Jun 26, 2007
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Everything posted so far is right on the button, i.e. if you stay with standard alkaline or NiMH cells, it's almost impossible to hurt the L0D.
This is because, unlike some of the other Fenix lights where Turbo is an overdrive situation, the L0D-Q4 is actually UNDERDRIVING the LED emitter even in it's highest mode. The L0D-Q4 only runs 75 lumens from a Q4 emitter rated at 100 lumens at 350ma (and which can handle even more current in a larger light with more heatsinking).
I have done runtime tests at full output till the battery ran flat several times with my L0D-Q4, and it only get's a little bit warm if you keep it in a position where it has reasonably good airflow (I set it on the edge of a box with the head hanging over the edge so it will have free airflow).
As has been mentioned already, running the L0D on a 10440 is another matter, because this significantly OVERDRIVES the emitter. Some L0D's have been fried by 10440's, because they just couldn't handle the high voltage and current levels from the 10440's. They either die outright or loose the lower modes (because the PWM MosFet fries and shorts out).
Even folks who get lucky with their L0D and find it works on 10440's can get a real unpleasant surprise if the light accidentally turns on in their pocket. With the heat trapped in an enclosed space like your pocket, an L0D running on a 10440 will get literally smoking hot in pretty short order.
If you want a little more brightness and don't mind paying a couple bucks each for disposables, the Energizer L92 aaa lithium cells are GREAT. Energizer L92's don't overstress the L0D because they run a different chemistry which gives them the same voltage as standard alkalines.
So, if you stay with Alkaline, NiMH, or L92's, you can use the highest mode on your L0D as much as you want.
This is because, unlike some of the other Fenix lights where Turbo is an overdrive situation, the L0D-Q4 is actually UNDERDRIVING the LED emitter even in it's highest mode. The L0D-Q4 only runs 75 lumens from a Q4 emitter rated at 100 lumens at 350ma (and which can handle even more current in a larger light with more heatsinking).
I have done runtime tests at full output till the battery ran flat several times with my L0D-Q4, and it only get's a little bit warm if you keep it in a position where it has reasonably good airflow (I set it on the edge of a box with the head hanging over the edge so it will have free airflow).
As has been mentioned already, running the L0D on a 10440 is another matter, because this significantly OVERDRIVES the emitter. Some L0D's have been fried by 10440's, because they just couldn't handle the high voltage and current levels from the 10440's. They either die outright or loose the lower modes (because the PWM MosFet fries and shorts out).
Even folks who get lucky with their L0D and find it works on 10440's can get a real unpleasant surprise if the light accidentally turns on in their pocket. With the heat trapped in an enclosed space like your pocket, an L0D running on a 10440 will get literally smoking hot in pretty short order.
If you want a little more brightness and don't mind paying a couple bucks each for disposables, the Energizer L92 aaa lithium cells are GREAT. Energizer L92's don't overstress the L0D because they run a different chemistry which gives them the same voltage as standard alkalines.
So, if you stay with Alkaline, NiMH, or L92's, you can use the highest mode on your L0D as much as you want.
