It's really hot!

[spyrish]

I was wearing jeans and carrying my Haiku XR-E in my front pocket today. After a few hours I noticed that my hip area was bothering me. I was sitting and took my pen out of the back pocket thinking that was what was bothering me. Well, my hip kept bugging me and I then looked down to notice that my light was on.

I'm not sure how long it was on, I don't think more than a few minutes, but it was on high, and really hot! I couldn't hold it and had to put it on the counter to cool down. I don't think its ever gotten that hot before, so I was just wondering what could happen.

Is it ok to hold or use any of the Haiku's XR-E, XP-G, XL-M in an open environment sitting or holding on high with a fresh battery from start to finish?

I've had this light for a while and do love it! I hope add another to my collection soon.

 

[McGizmo]

Hi Spyrish,
My personal rule of thumb is don't burn my thumb; that is to say if the light gets uncomfortably hot to hold then back it down. I think you can find that with some lights if you are holding them, you can continue to do so even though they get obviously warm. However should you set the light down it could elevate in temperature further to the point you would not want to hold it. The lights do generate heat and this heat needs to be dissipated. Having a light on in your pocket is certainly a place where it can get too hot. I am frankly not sure how to answer your question about being OK because the ambient temperature and ability of the light to pass on its heat plays a significant role in how hot it might get. The Cree LED's can handle heat well above our comfort threshold. The XM-L by virtue of having the best efficacy of the group will run cooler than the others with all other things equal.

 

[spyrish]

Thanks for the reply Don. :)

That answered my question. I just wanted to know if damaged could occur from heat because of the light running too long. I don't use my lights that way, but one never knows.

 

[Cypher_Aod]

Certainly the LEDs can be damaged by running them at high temperatures, but usually they either need to be sustained (like a few hundred hours) or really really really hot, which I think you would have noticed by the 1st degree burns on your leg.

You should be fine but try to keep an eye on it in the future.

<edit> in case you were interested, Cree specify thermal tolerances in the XR-Es datasheet:
http://www.cree.com/products/pdf/XLamp7090XR-E.pdf

:)
Sent from my HTC Vision using Tapatalk

 

[jumpstat]

What effects that extreme heat does to the batts? If I am not mistaken, protected rechargeable cells do have temp protection, what about primary cells? They are almost double capacity and can run for ages. Venting batts would be an issue.

I did have an experience with a notebook which I thought was off when I put it in the case and went home like 1 hour 30 minutes later and I can tell you that there is a distinctive smell when I open the case after the fact. Lucky for me that the notebook run as usual but the rechargeable couldn't hold much charge after the incident...

 

[fyrstormer]

That answered my question. I just wanted to know if damaged could occur from heat because of the light running too long. I don't use my lights that way, but one never knows.

I don't know if anyone's ever done a hands-off hot-weather full-power battery-drain test on their Haiku, but if damage occurs, you'll see the yellow phosphor start to turn brown. The emitter board is replaceable, however, and even if the emitter board were to become no longer available, someone could install a new emitter on the existing emitter board. In fact, your Haiku will probably last long enough that you'll get the emitter replaced anyway, just to keep up with the times.

The beauty of a modular design is that it can be disassembled and repaired as necessary. Don't sweat too much about it.