More than just using the head to heat water for tea, this looks like some other severe heat issues.
The XM-L datasheet mentions max junction temp of 150C. The thermal path can’t be bad with the head heating so quickly. With the external temp pushing towards 100C after 30 seconds junction temp still has to be high. Accelerated aging of the LEDs is at least not dangerous.
The cells worry me more. The good news is they are reasonably insulated from the body temp. There’s some air gap between them with only a small surface area of shrink wrap actually in contact. The bad news is waste heat from internal resistance is based on the square of current - W = I^2 * R. A quick google just put me in the ballpark of 9-100 mOhm per cell. .027-.3Ohms for the three in series. With a 6A draw that’s .97 to 10.8 Watts of waste heat inside the cells. We can kind of ignore internal resistance heating in most cases but a 6A draw quadruples a 3A draw and is nine times a 2A draws heating. Again they’re pretty well insulated so that won’t spread that quickly once the light is off. The head will cool faster than the cells giving a possibly false impression. This certainly isn’t a light where I would even think about using cells that showed a higher than normal voltage sag under heavy load.
I be interested in some temperature measurements of the cells themselves after a run on max.
Hi FMCamaro, hope you don’t mind I post this in your thread.
Just received my Sky Ray 9xT6 from Ric today. Looks great and all was flawless as FMCamaro indicated in his review. Using 3 Trustfire TF-26650 5000mAh (43000mAh actual) fully charged to 4.20v, current reading on HIGH mode was exactly 3.68 amps. These trustfire batteries don’t sag much at all, no doubt why on high mode the amp draw seems low. I’ll take some beam shots tonight comparing it to my Trustfire TR-J12, Skyray King CW version, and perhaps my DRY.
Use thick wires for current measurement. You could test following, measure tailcapcurent then while you are measuring short the tips of the multimeter if the output of light increase your wires are to thin….hope you get what I mean.
The heat “issue” is only at warm temperatures, so if I now go out in the cold it gets warm but not hot. Wind and convection adds additional cooling. And at all you have think about that the power decreases continuously because we are using 4Ah Batteries for 6A so voltage drops every minute and this beast is not regulated…
If I put it in my living room with 73 degree Fahrenheit (23degree Celsius) and no wind it gets very hot very fast I have done this once and had to cool it with water…outside no problem.
Warm batteries are good because more powerful…
With standard leads I get 3.x amps too.
I’ve done a quick walk outside and this thing is so bright I love it, normally you have a tight spot far away which is bright or you have a floods bright is in front of you, but with this you have everything bright.
No real heat at 30F outside temp. Just normal warm body, so sad that I have no temperature sensor which is suitable for this…
So now I have to charge my batts again, tomorrow there will be snow and with that reflective thing everywhere I will need sunglasses
One thing happens often there is condensation on the middle of the glass, where the three LEDs are in the center….
Okay folks, I switched out my standard DMM cables for much heavier 12 gauge wires and get 4 amps on high mode up from 3.68a. I still think it has something to do with these Trustfire 26650 cells. These cells can really handle a lot of draw put on them.
I also tested it with 3 X Redilast 3100 18650’s charged to 4.2v and got 3.5a on HIGH. This reading was also using the 12 gauge probes on my DMM.
Here are some beam shots comparing the Skyray 9 to a few others. Not the best photos, but I did use a tripod for the camera. Funny thing is there wasn’t much of a difference in output for the first 3 lights until I tried the Skyray 9XT6.
The Trustfire TR-J12 and SkyRay 9XT6 both had fully charged 3X Trustfire 26650 flames 5000mAh installed, and the DryTurbo and Skyray KING had Redilast 18650 3100mAh.
first off. thanks for them beam shots. secondly, i did not know the tr j12, was thaaaat much brighter and floodier than the king. i mean its not that much, but easily noticable.
and i didnt even know that the dry was brighter and floodier than the king, i thought it was the other way around.
but dude, that skyray 9 is a killer! geez that thing is bright. if they made a stubby version, id be all over it!
i still want to wait for review on that new 12xml, if its not as floody, then i may have to purchase this sky 9
Can somebody recommend some good 26650’s for this flashlight? I dont own any of these batteries yet and I’d like to buy some quality ones that will fit in this light. What do you guys recommend?
I was thinking these, but I dont mind paying more for something quality
Those will work just fine. You may want to wait a bit and see if anyone else chimes in who is using them however. My keeppower’s protected’s were too long to allow the tail cap to fully screw down.
Maybe someone can get a length measurement of a protected TF 26650 and ill do the same for my Keeppowers, this way we will know if they definitely fit before you buy them.
I also have to still do those outdoor beamshots. My 26650’s are charging.
I also have some pictures of the inside of the head and the driver.
I use these Trustfire batteries in all my powerful 26650 size lights. They are simply great and afford the maximum runtime. I’ve only purchased them from Manafont and also have 3 more Trustfires on the way, which will live with the Skyray 9T6 exclusively, and should arrive this week. Just be careful you are not purchasing fakes, as they can be dangerous in a powerful light like this.
