LED Heat Question

Hitthespot

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Just a curiosity question. I have read a lot of threads about people being concerned about their LED drop in or their LED flashlight LED overheating. These questions have just recently been brought up in G2 drop in threads and in threads about Fenix Turbo modes.

Since I have only been around the forum for a month or so, my question is....Is there or has there been problems with any drop ins / Led flashlights burning out the leds due to heat? Again I'm just wondering if this has been a real problem or is it just a concern because one day on brand x or y it could be a problem and I really should watch before buying.
 

Gunner12

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The Seoul P4's phosphor seems to be more affected by heat. The light shifts blue if the LED is overheating.

Specific problems, I don't recall any under normal usage.
 

Hitthespot

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The Seoul P4's phosphor seems to be more affected by heat. The light shifts blue if the LED is overheating.

Specific problems, I don't recall any under normal usage.


That's what I thought. It something you really probably never have to worry about unless a manufacturer makes some grave error which I'm sure they would take care of.

Thanks Gunner I see you've been around for a few posts so if there had been any specific recalls or failures in the last year or so you would have heard about it. Again thanks.
 

Gunner12

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Failures from heat, I've heard of but I don't think any of them would fall under normal circumstances(there's probably a few that have failed from normal circumstances but I don't recall any).

One I remember was a Cree XR-E bare emitter being driven at 2 amps with no heatsink(don't recall the bin or the thread it was posted on). I think it died withing half an hour.

There has been a few posts about cheap 5mm LED lights(mostly 9 led 3 AAA ones) dieing from heat but that is expected.

From what I've seen, these high power LEDs are surprisingly resilient to overdrive and heat compared to the 5mm LEDs.

Edit: There has been a few posts of the Amilite T5 dimming by using a RCR123 battery. I think it was an overheating problem.
 
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Hitthespot

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Failures from heat, I've heard of but I don't think any of them would fall under normal circumstances(there's probably a few that have failed from normal circumstances but I don't recall any)quote]

I was talking about "Normal Circumstances"

Thanks

Bill
 

Gunner12

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The only one I could remember is the Amilite T5 problems during spring this year(Seoul P4 U bin). Some of the lights became dim(bright at first but something broke) when driven with a RCR123 battery(3.7v kind). The RCR123 battery was not supported but some reported no problems while others has browning and dimming LEDs(overheating I think).

Haven't heard of any problems since then.
 

Hitthespot

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It sounds like were all pretty safe. After reading so many threads about overheating an LED I was getting afraid to turn mine on. That's an exageration of course but somewhat true also. I don't think my G2 with Q5 drop in or my Olight T20 Q5 is going to burn up if it takes me an hour to get out of the woods. Well I hope there's no problems, I really like Tiablo's A1 and the New Fenix T1 so I don't plan on slowing down on my purchasing.

Any one know if there is a third party Q5 drop in for the E2E?

Bill
 

hopkins

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Concerning the supposed fatal overheating on the 3watt Petzl MYO XP
if lithium AA's are used.

Against the advice on the Petzl web page on overheating the 3watt Luxeon
I put lithium AA's into my MYO XP, to reduce weight and maximize burntime.

If the outdoor ambient temperature is cold I calculate the LED will not overheat as there is always a little wind (sometimes alot) night hiking/skiing.

But for warmer temps and no wind I'll only use medium and low settings for extended use, say inside tents or sweltering summer night hikes.

The boost funstion used for only a second or two is probably safe or is it ?

Any other MYO XP owners out there who've used lithiums in this fashion
to minimize killing the 3watt Luxeon?

Or does the circuitry fry first ?

I'll probably just use Rayovac hybrid AA's after the lithiums go dead.
 
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