hot/warm flashlight, what does it mean? (Fenix LD15)

hello, i have a fenix LD15 and as i was using it last night it was getting very, very warm, almost hot. its not the first time its happened. i had been using it on high mode consistantly for about 30mins before i turned it off. my question is why is my light getting so hot?:thinking: and with it being so hot, will that affect the lifespan of my light? does it cause any damage to the bulb, batteries, or flashlight? is this supposed to be normal? any input is appreciated. thanks in advance.

LED's do get hot, especially when operating at high output for extended periods of time, this is normal most of the time, although I don't own an LD15 so it's difficult for me to determine how hot that light should get under certain conditions, but judging from your description I'm not concerned with any issues. If the light is just hot, the best idea is to ramp down the output level and give it a chance to cool. If the light is so hot you can't hold onto it, then you're running it way too hard or their may be some other type of issue. Yes, excessive heat can have a significant effect on the led's lifespan, but that's only in certain cases where the light gets extremely hot for an extended period of time.

What type of battery are you using?

I've noticed the same thing with my LD15. After all it's a very small 1AA flashlight putting out 117lm and it normaIly gets quite warm after 5-10 minutes - it depends on outside temperature and whether it's held in hand or not (it doesn't get too hot to touch, though).

LD15's LED and driver are potted inside the brass pill, and getting warm on its outer surfaces means that its heatsinking works (heat is drawn away from the vital components). As ebow86 said, switch it to Low and let it cool for a while if it gets hot.

Cheers,

Tam

Looking at the specs,
Max Lifespan: 50,000 Hours
Max Output: 117 Lumens
Max Runtime: 39 Hours
I doubt you get the maximums all at the same time. I'd ask Fenix what lifespan you can expect at 117 lumens. For almost anything, hotter temps shorten life.

If you have a resistor with the same surface area as this flashlight you can run some watts into it and compare surface temps and get some idea of how many watts this light is putting out in nonradiant flux.

Or, use an emissivity-adjusted IR meter on your light and run a calculation.