Preon 2 Ti gets hot very quickly

[jimahi]

Just got the Preon 2 Ti and it is a really nice light! But I am wondering... on high, is this thing supposed to be used for more than a few minutes? Without holding it properly, it gets quite hot to the touch in about 5 minutes. Even when holding it, it becomes uncomfortably warm to hold after 7 or 8 mins. Another thing I have found is that you have to hold it on the head to get the heatsinking, because the heat doesn't seem to distribute down the body very well. If you hold it about an inch back from the front bezel (about at the head/body junction), then it doesn't seem to get too warm - but 'ouch' if you move your finger up to the front of the head. So when running on high, it seems that you have to hold it right at the front of the head to get the proper body heatsinking - and when doing that it becomes quite uncomfortable after about 8 mins

Is it supposed to get this hot (since there is such a small heat dissipation space), or might I have a bad one? Mine is running on 2 AAA Eneloops.

Jim

 

[jirik_cz]

Another thing I have found is that you have to hold it on the head to get the heatsinking, because the heat doesn't seem to distribute down the body very well.

Seems like exactly the same behavior as shown here http://www.candlepowerforums.com/vb/showthread.php?t=248274

Maybe it is not a good idea to make such a small and powerful light from titanium alloy.

 

[Gunner12]

Titanium does not transmit heat as well as Al, so the heat can build up.

 

[dudu84]

Just got the Preon 2 Ti and it is a really nice light! But I am wondering... on high, is this thing supposed to be used for more than a few minutes? Without holding it properly, it gets quite hot to the touch in about 5 minutes. Even when holding it, it becomes uncomfortably warm to hold after 7 or 8 mins. Another thing I have found is that you have to hold it on the head to get the heatsinking, because the heat doesn't seem to distribute down the body very well. If you hold it about an inch back from the front bezel (about at the head/body junction), then it doesn't seem to get too warm - but 'ouch' if you move your finger up to the front of the head. So when running on high, it seems that you have to hold it right at the front of the head to get the proper body heatsinking - and when doing that it becomes quite uncomfortable after about 8 mins

Is it supposed to get this hot (since there is such a small heat dissipation space), or might I have a bad one? Mine is running on 2 AAA Eneloops.

Jim

I expected it to get rather hot on max, especially for the Ti Preon II, which is exactly the reason why I decided not to make it a present to a non-flashaholic friend.

Assuming the same losses due to optics as in Quark Turbo (@250mA) of ~17%, to get 160 lumens OTF, the R5 is probably fed with a current of ~500mA that can be too much for the tiny Preon head. Preon I shouldn't have overheat problems I think.

Just my 2c

 

[f22shift]

Titanium does not transmit heat as well as Al, so the heat can build up.

so the aluminium version would be better if getting the 2aaa setup?

 

[jahxman]

so the aluminium version would be better if getting the 2aaa setup?

What's most important to the health of the flashlight is how hot the emitter is getting, which we wan't know without direct measurement, but I imagine 4sevens has made sure it stays within spec for the emitter.

The aluminum version is likely to condict heat away from the emitter more efficiently, which means that the surface of the light is likely to get warm and then possibly hot faster than the titanium - and the heat will spread more evenly across the body. The Titanium version will get most hot directly over the emitter, with a sharper temperature gradient down as you get further away.

So at steady state, some surface areas on a Ti light will be hotter (near emitter)than the Al version, and some will be cooler (near tail.)

 

[kaichu dento]

I'm another one not surprised that these tiny high output lights are getting hot, but I don't really worry about it as I think of high on most of my lights as a very short term selection and find medium to be usable for the majority of regular flashlight usage. YMMV.

 

[f22shift]

i wonder if this is why fenix used the aluminum body with their 2aa.

 

[davidt1]

Would Preon owners please test the lights with 10440 battery? I know what 4Sevens says, but they are just being cautious. CC says the same thing about using 10440 in the Maratac, but I have been using 10440 in my Maratac without any problem. The Preons should work the same way. I would much appreciate seeing some 10440 testing done with the Preons. I can't ask on the 4Sevens forum cos I am not registered there cos I refuse to register twice.

 

[EngrPaul]

i wonder if this is why fenix used the aluminum body with their 2aa.

But the head of the LD05 is stainless, wouldn't that be just as bad?

I don't plan to use my Preon II Ti on high except for burst. I wish there was a fourth output.

 

[OfficerCamp]

I think the max voltage the Preon head can handle is 3v (per 47 website), you may end up blowing up your new light if you throw in a lithium ion.

 

[Marduke]

Would Preon owners please test the lights with 10440 battery? I know what 4Sevens says, but they are just being cautious. CC says the same thing about using 10440 in the Maratac, but I have been using 10440 in my Maratac without any problem. The Preons should work the same way. I would much appreciate seeing some 10440 testing done with the Preons. I can't ask on the 4Sevens forum cos I am not registered there cos I refuse to register twice.

But the XPG has an even lower Vf, making direct drive off a 10440 quite dangerous.

Also, isn't it a bit childish to refuse to register in the MarketPlace? You can use the same login and password so it seems like a single forum with CPF proper.

 

[moses]

I did not recoomend the Ti precise for that concern, electing to go with Al models for my friends. It'll be interesting to see what others are finding as these become popular. It is a remarkable light - so many lumens for so small a light.

Moses

 

[gswitter]

Would Preon owners please test the lights with 10440 battery? I know what 4Sevens says, but they are just being cautious. CC says the same thing about using 10440 in the Maratac, but I have been using 10440 in my Maratac without any problem. The Preons should work the same way.

What are you basing this statement on?

The MaraTac AAA and Preon are two different lights from two different companies (probably two different manufacturers) with two different drivers. Why would you assume two different drivers in two different hosts behave the same way when both are powered by voltage that's above spec?

I would much appreciate seeing some 10440 testing done with the Preons.

How about frying your own light?!?!

 

[Dobbler]

 

[madmook]

Crud, never though about this when I ordered a Ti Preon 2 (still waiting for USPS to deliver mine). Never had a titanium light before, and thought, "What the hey I'll give it a try."

The 160 lumen high is what convinced me to get a Preon, but if I can only use it 7 minutes at a time on that brightness before it gets too hot to hold, that's gonna put a damper on how I feel about it...

 

[Pontiaker]

But the head of the LD05 is stainless, wouldn't that be just as bad?

I don't plan to use my Preon II Ti on high except for burst. I wish there was a fourth output.

Actually it would be worse, Ti handles the heat sinking better than stainless steel...Same as aluminum is better than Ti.

 

[Pontiaker]

Does anyone know if the Ti used is CP or an alloy like 6al4v?


I could care less if my light gets hot when I use it on high, as long as its not too hot to touch. If it is thats what the lower modes are for or I hold it by the back end....Kind of seems like common sense here guys...If its so bad that people are getting burned or the LED is not lasting long Iam sure 4 7's will take care of it. The onlt reason I would ever use a AAA light is for a ultra small bright single cell, you start stacking it up and you defeat the purpose, might as well go with a couple of 123 for way more power, and a shorter though fatter light....

 

[dudu84]

i wonder if this is why fenix used the aluminum body with their 2aa.

If you meant 2aaa -> Not only that, they advertise max brightness of only 100 lumens (probably LED lumens) for the LD05, meaning the current will be less than 350mA so the LED will be under-driven on all modes.

I think thus far, Fenix has always played safe by not over-driving the LEDs on any of their series and up-front about overheat issues, which are good for long-term use but might seem a little "boring" for many of us

 

[Pontiaker]

If you meant 2aaa -> Not only that, they advertise max brightness of only 100 lumens (probably LED lumens) for the LD05, meaning the current will be less than 350mA so the LED will be under-driven on all modes.

I think thus far, Fenix has always played safe by not over-driving the LEDs on any of their series and up-front about overheat issues, which are good for long-term use but might seem a little "boring" for many of us

Thats why we build things like the Streamix, the Streamlight body and clicky tailcap with the Fenix LOD or LD01 head and run a 10440 battery.This thing screams compared to any other single aaa light I have ever used. I dont mind the short runtime on High or the heat issue, thats what the other two moeds are for....