Re: Heat from AKOray K-106 Q5 14500
It's overheating. IF you hold the light and your hand absorbs the heat, to the point where the head tube is cooler, that has a direct relationship to a corresponding reduction in temperature of the driver and LED.
I was concerned about this, it seems that the original 3 mode programmable K-106 is ok with 4.2V Li-Ion, but the other two are like many of DX's lights, they direct drive which is fine with a beefy enough driver and large light/pill, not so much with a little AA diameter light. It's possible with a little AA light but you move to purpose specific materials and overbuilt drivers, rasing the cost compared to all alumium pill, barely double sided boards with no vias on heatsinked pads.
Simple answer that will prolong the life of your batteries and your flashlight, don't charge them past 4.0V so the flashlight never direct drives at such a high voltage.
For the benefit of others if you would measure the battery current yours consumes on this high mode, we can add it to the collective knowledge about these new K-106 variants.
I should add, when I wrote it is overheating I am trying to be objective. Subjectively, given some people don't use their light for long periods and that LEDs get better every year, and that the light is so inexpensive, so long as it doesn't go
at a critical moment, it could be useful to have it a bit brigher... but too many people feel it is a lottery, it may work one day and be gone the next if it feels that hot that quickly.
How you'll know depends on how hot it gets internally, and can change with random variations in quality control. Running that hot it tends to degrade the LED over time, including immediate reduction in efficiency so you end up using more battery current for little if any more light than if set at a little lower mode (especially since eyes adjust well to a few dozen % difference in output). Worst case is some people see a sudden failure, presumably repetitive overheating of the transistor delaminates the copper on the driver board and it overheats and/or the copper deforms and oxidizes away, opening the circuit.
It's overheating. IF you hold the light and your hand absorbs the heat, to the point where the head tube is cooler, that has a direct relationship to a corresponding reduction in temperature of the driver and LED.
I was concerned about this, it seems that the original 3 mode programmable K-106 is ok with 4.2V Li-Ion, but the other two are like many of DX's lights, they direct drive which is fine with a beefy enough driver and large light/pill, not so much with a little AA diameter light. It's possible with a little AA light but you move to purpose specific materials and overbuilt drivers, rasing the cost compared to all alumium pill, barely double sided boards with no vias on heatsinked pads.
Simple answer that will prolong the life of your batteries and your flashlight, don't charge them past 4.0V so the flashlight never direct drives at such a high voltage.
For the benefit of others if you would measure the battery current yours consumes on this high mode, we can add it to the collective knowledge about these new K-106 variants.
I should add, when I wrote it is overheating I am trying to be objective. Subjectively, given some people don't use their light for long periods and that LEDs get better every year, and that the light is so inexpensive, so long as it doesn't go
at a critical moment, it could be useful to have it a bit brigher... but too many people feel it is a lottery, it may work one day and be gone the next if it feels that hot that quickly.How you'll know depends on how hot it gets internally, and can change with random variations in quality control. Running that hot it tends to degrade the LED over time, including immediate reduction in efficiency so you end up using more battery current for little if any more light than if set at a little lower mode (especially since eyes adjust well to a few dozen % difference in output). Worst case is some people see a sudden failure, presumably repetitive overheating of the transistor delaminates the copper on the driver board and it overheats and/or the copper deforms and oxidizes away, opening the circuit.
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50.0g) Head Dia.
